Produced by Nick Hodson of London, England




The Red Room, by William Le Queux.

________________________________________________________________________















________________________________________________________________________
THE RED ROOM, BY WILLIAM LE QUEUX.

CHAPTER ONE.

THREE INQUISITIVE MEN.

The fifteenth of January, 1907, fell on a Tuesday.  I have good cause to
remember it.

In this narrative of startling fact there is little that concerns
myself.  It is mostly of the doings of others--strange doings though
they were, and stranger still, perhaps, that I should be their
chronicler.

On that Tuesday morning, just after eleven o'clock, I was busy taking
down the engine of one of the cars at my garage in the High Road,
Chiswick.  Dick, one of my men, had had trouble with the "forty-eight"
while bringing home two young gentlemen from Oxford on the previous
night, and I was trying to locate the fault.

Suddenly, as I looked up, I saw standing at my side a man who lived a
few doors from me in Bath Road, Bedford Park--a man who was a mystery.

He greeted me pleasantly, standing with his hands thrust into the
pockets of his shabby black overcoat, while, returning his salutation, I
straightened myself, wondering what had brought him there, and whether
he wished to hire a car.

I had known him by sight for a couple of years or more as he passed up
and down before my house, but we had not often spoken.  Truth to tell,
his movements seemed rather erratic and his shabbiness very marked, yet
at times he appeared quite spruce and smart, and his absences were so
frequent that my wife and I had grown to regard him with considerable
suspicion.  In the suburbs of London one doesn't mix easily with one's
neighbours.

"Can I speak to you privately, Mr. Holford?" he asked, with a slight
hesitancy and a glance at my chauffeur Dick, who at that moment had his
hand in the gear-box.

"Certainly," I said.  "Will you step into my office?"  And I led the way
through the long garage to my private room beyond, through the glass
windows of which I could see all the work in progress.

My visitor was, I judged, about fifty, or perhaps fifty-five, an
anxious, slight, intellectual-looking man, with hair and moustache
turning grey, a pair of keen, dark, troubled eyes, a protruding,
well-shaven chin, an aquiline face, sniffing dimly the uncertain future,
a complexion somewhat sallow, yet a sinewy, athletic person whose
vocation I had on many occasions tried to guess in vain.

Sometimes he dressed quite smartly in clothes undoubtedly cut by a
West-End tailor.  At others, he slouched along shabby and apparently
hard up, as he now was.

My wife--for I had married three years before, just after I had entered
the motor business--had from the first put him down as an adventurer,
and a person to be avoided.  Her woman's instinct generally led to
correct conclusions.  Indeed, one night, when out with her sister, she
had seen him in evening dress, seated in a box at a theatre with a lady,
in pale blue and diamonds, and another man; and on a second occasion she
had witnessed him at Charing Cross Station registering luggage to the
Continent.  He had with him two smartly-dressed men, who were seeing him
off.

I myself had more than once seen him arrive in a hansom with well-worn
suit-cases and travelling kit, and on several occasions, when driving a
car through the London traffic, I had caught sight of him in silk hat
and frock-coat walking in the West End with his smart friends.

Women are generally inquisitive regarding their neighbours, and my wife
was no exception.  She had discovered that this Mr. Kershaw Kirk was a
bachelor, whose home was kept by an unmarried sister, Miss Judith, about
nine years his junior.  They employed a charwoman every Friday, but, as
Miss Kirk's brother was absent so frequently, they preferred not to
employ a general servant.

Now, I was rather suspicious of this fact.  The man Kirk was a mystery,
and servants are always prone to pry into their master's affairs.

My visitor was silent for a few moments after he had taken the chair I
had offered.  His dark eyes were fixed upon me with a strange, intense
look, until, with some hesitation, he at last said:

"I believe, Mr. Holford, you are agent for a new German tyre--the
Eckhardt it is called, is it not?"

"I am," I replied.  "I am sole agent in London."

"Well, I want to examine one," he exclaimed, "but in strict confidence.
Other persons will probably come to you and beg to see this particular
tyre, but I wish you to regard the fact that I have seen it as entirely
between ourselves.  Will you do so?  A very serious issue depends upon
your discretion--how serious you will one day realise."

I looked at him in surprise.  His request for secrecy struck me as
distinctly peculiar.

"Well, of course, if you wish," I replied, "I'll regard the fact that
you have seen the Eckhardt non-skid as confidential.  Is it in
connection with any new invention?"  I asked suspiciously.

"Not at all," he laughed.  "I have nothing whatever to do with
motor-cars or the motor trade.  I merely wish to satisfy myself by
looking at one of the new tyres."

So I went upstairs, and brought down one of the German covers for his
inspection.

He took it in his hands, and, very careful that Dick should not observe
him from the outside, closely examined the triangular steel studs with
which the cover was fitted.

From his pocket he took a piece of paper, and, folding it, measured the
width of the tyre, making a break in the edge of the folded paper.  Then
he felt the edges of the studs, and began to ask questions regarding the
life of the new tyre.

"The inventor, who lives at Cologne, was over here three months ago, and
claimed for it that it lasted out three tyres of any of the present
well-known makes," I replied.  "But, as a matter of fact, I must admit
that I've never tried it myself."

"You've sold some, of course?"

"Yes, several sets--and I believe they've given satisfaction."

"You are, I take it, the only agent in this country?"

"No; Farmer and Payne, in Glasgow, have the agency for Scotland," I
replied, greatly wondering why this tyre should attract him if he had no
personal interest in cars.

A second time he examined the cover, again very closely; then, placing
it aside, he thanked me, apologising for taking up my time.

"Mind," he said, "not a word to a soul that you have shown me this."

"I have promised, Mr. Kirk, to say nothing," I said; "but your
injunctions as to secrecy have, I must confess, somewhat aroused my
curiosity."

"Probably so."  And a good-humoured smile overspread his thin, rather
melancholy face.  "But our acquaintance is not very intimate, is it?
I've often been on the point of asking you to run in and have a smoke
with me.  I'm a trifle lonely, and would be so delighted if you'd spend
an hour with me."

My natural curiosity to discover more about this man, who was such a
mystery, prompted me to express a mutual desire for a chat.

So it was arranged that I should look in and see him after dinner that
same evening.

"I travel a good deal," he explained, in a careless way, "therefore I
never like to make engagements far ahead.  I always believe in living
for to-day and allowing to-morrow to take care of itself."

He spoke with refinement, and, though presenting such a shabby exterior,
was undoubtedly a gentleman and well bred.

He looked around the garage, and I showed him the dozen or so cars which
I let out on hire, as well as the number of private cars whose owners
place them in my care.  But by the manner he examined them I saw that,
whatever ignorance he might feign regarding motors, he was no novice.
He seemed to know almost as much about ignition, timing, and lubrication
as I did.

And when I remarked upon it his face only relaxed into a smile that was
sphinx-like.

"Well, Mr. Holford," he exclaimed at last, "I'm hindering you, no doubt,
so I'll clear out.  Remember, I'll expect you for a chat at nine this
evening."  And, buttoning his frayed overcoat, he left, and walked in
the direction of Turnham Green.

Half an hour later I was called on the telephone to the other side of
London, where I had a customer buying a new car, and it was not before
six o'clock that I was back again at the garage, where I found my
manager, Pelham, who during the morning had been out trying a car on the
Ripley road.

"Funny thing happened this afternoon, sir," he said as I entered.  "Two
men, both mysterious persons, have come in, one after the other, to see
an Eckhardt non-skid.  They had no idea of buying one--merely wanted to
see it.  The second man wanted me to roll one along in the mud outside
to show him the track it makes!  Fancy me doing that with a new tyre!"

His announcement puzzled me.  These were the persons whose visit had
been predicted by Kirk!

What could it mean?

"Didn't they give any reason why they wanted to see the cover?"

"Said they'd heard about it--that was all," my manager replied.  "Both
men wanted to take all sorts of measurements, but I told them they'd
better buy a set outright.  I fancy it's some inventor's game.  Somebody
has got a scheme to improve on it, I expect, and bring it out as a
British patent."

But I kept my counsel and said nothing.  I was already convinced that
behind these three visits there was something unusual, and I determined
to endeavour to extract the truth from Kershaw Kirk.

Little did I dream the reason why the Eckhardt tyre was being so closely
scrutinised by strangers.  Little, likewise, did I dream of the curious
events which were to follow, or the amazing whirl of adventure into
which I was to be so suddenly launched.

But I will set it all down just as it happened, and try to present you
with the complete and straightforward narrative--a narrative which will
show you what strange things can happen to a peaceful, steady-going,
hard-working citizen in this Greater London of ours to-day.

CHAPTER TWO.

SOME STRANGE FACTS.

Mr. Kirk opened his front door himself that evening, and conducted me to
a cosy study at the end of the hall, where a fire burned brightly.

In a black velvet lounge coat, a fancy vest, and bright,
bead-embroidered slippers, he beamed a warm welcome upon me, and drew up
a big saddle-bag arm-chair.  From what I had seen of the house, I was
surprised at its taste and elegance.  There was certainly no sign of
poverty there.  The study was furnished with solid comfort, and the
volumes that lined it were the books of a studious man.

The cigar he offered me was an exquisite one, though he himself
preferred his well-coloured meerschaum, which he filled from an old
German tobacco bowl.  In one corner of the room stood his pet, a large
grey parrot in a cage, which he now and then addressed in the course of
his conversation.

One of his eccentricities was to think audibly and address his thoughts
to his queer companion, whose name was Joseph.

We must have been chatting for fully half an hour when I mentioned to
him that two other persons had called that afternoon to inspect the new
Eckhardt tyre, whereupon he suddenly started forward in his chair and
exclaimed:

"One of the men wore a dark beard and was slightly bald, while the other
was a fair man, much younger--eh?"

I explained that my manager, Pelham, had seen them, whereupon he
breathed more freely; yet my announcement seemed to have created within
him undue consternation and alarm.

He pressed the tobacco very carefully and deliberately into his pipe,
but made no further comment.

At last, raising his head and looking straight across at me, he said:

"I may as well explain, Mr. Holford, that I had an ulterior motive in
asking you in this evening.  The fact is, I am sorely in want of a
friend--one in whom I can trust.  I suppose," he added--"I suppose I
ought to tell you something concerning myself.  Well, I'm a man with
many acquaintances, but very few friends.  My profession?  Well, that is
surely my own affair.  It often takes me far afield, and sometimes
causes me to keep queer company.  The fact is," he said, after a
moment's hesitation, "I'm a dealer in secrets."

"A dealer in secrets!"  I echoed.  "I don't quite follow you."

"The secrets sometimes confided to my keeping would, if I betrayed them,
create a worldwide sensation," he said slowly, looking straight into the
fire.  "At times I am in possession of ugly facts concerning my
fellow-men which would eclipse any of the scandals of the past twenty
years.  And at this moment, as I tell you, I am in sad need of a
friend."

He was quick to notice the expression upon my face.

"I want no financial aid," he hastened to assure me.  "On the contrary,
if at any time I can be of any little assistance to you, I generally
have a few pounds lying idle."

I thanked him, my curiosity growing greater.  He was seated in a big,
high-backed grandfather's chair, his head leaning against the padded
side, his gaze, a trifle melancholy, fixed upon the dancing flames.  At
his back was an open roll-top writing-table, very tidy, with a clean
blotting-pad, and everything in its place, spick and span.

"To be quite frank with you, Mr. Holford," he said, "I may as well tell
you that an incident has occurred which has rendered it necessary that I
should come to you, a comparative stranger, for friendship and
assistance.  Ah," he added, with a sharp and curious glance at me, "I
see that you don't trust me!  You should never judge a man by his
clothes."

"I never do," I protested.  "But you haven't explained the reason why
you are so anxious for my friendship!"

For a few minutes he was silent.  Then, of a sudden, he turned to the
big grey parrot and asked in a shrill, squeaky tone, almost a croak:
"Shall I tell him, Joseph?  Shall I tell him?"

"Good night!" answered the loquacious bird.  "Good night!  Good night!
Josef!"

"Well," my host said slowly, knocking the ashes from his pipe into the
fender, "it is a matter, a serious and very curious affair, of which as
yet the public have no knowledge.  Some things are not allowed to leak
out to the papers.  This is one of them.  I wonder," he went on
thoughtfully, after a pause--"I wonder if I told you whether you would
keep the secret?"

"Certainly," I said, full of curiosity, for I could not see Kirk's
motive in asking my assistance, and my natural caution now asserted
itself.

"By the way," he echoed suddenly, "do you know any other language
besides English?"

"I know French fairly well," I replied, "and a smattering of Italian."

"Nothing else?  German, for instance?"

I replied in the negative.

He rose, and relit his pipe with a spill.  Then he chatted for some
minutes with Joseph, all the time, it seemed, reflecting upon what he
should say to me.  At last, reseating himself in his old-fashioned
chair, he again looked me straight in the face and said:

"You have given me your promise of silence, Mr. Holford.  I accept it
from one whom I have watched closely for a long time, and whom I know to
be a gentleman.  Now I am going to tell you something which will
probably alarm you.  A crime, a very serious crime, has been committed
in London during the past forty-eight hours, and I, Kershaw Kirk, am
implicated in it--or, rather, suspected of it!"

I sat staring at the man before me, too surprised to reply.  He had
always been an enigma, and the mystery about him was increasing.

"Tell me more," I urged at last, looking into the face of the suspected
criminal.  "Who is the victim?"

"At present I am keeping the affair a strict secret," he said.  "There
are reasons, very potent reasons, why the public should not know of the
tragedy.  Nowadays publicity is the curse of life.  At last the Home
Office have recognised this.  I told you that I am a holder of secrets.
Well, besides myself, not more than three persons are aware of the
astounding affair."

"And you are suspected as the assassin?"  I remarked.

"Unfortunately, I shall be," was his reply, and I saw that his
countenance fell; "I foresee it.  That is why I require your aid--the
aid of a man who is honest, and who is a gentleman as well."

And he broke off again to chatter to Joseph, who was keeping up a
continual screeching.

"I am anxious to hear details of the affair," I said eagerly.

"I wish I could tell you the details," he answered, with a bitter smile;
"but I am not aware of them myself.  The affair is a mystery--one of
which even the police must be kept in ignorance."

"Haven't the police been informed?"

"No," was his prompt reply.  "In certain cases information to the police
means publicity.  In this case, as I've already told you, there must be
no publicity.  Therefore, though a crime has been committed, it is being
kept from the police, who, not knowing the facts, must only bungle the
inquiries, and whose limited scope of inquiry would only result in
failure."

"You interest me, Mr. Kirk.  Relate the known facts to me," I said.
"Why, pray, will you be suspected of being a murderer?"

"Well," he said, with a long-drawn sigh, "because--well, because I had
everything to gain by the death of the murdered person.  He had filched
from me a very valuable secret."

"Then the murdered person was not your friend?"

"No; my enemy," he replied.  "You, Mr. Holford, as an Englishman, will
no doubt think it impossible that I may be arrested, tried in secret,
and sent to penal servitude for life for a crime of which I am innocent.
You believe that every man in this isle of unrest of ours must have a
fair trial by judge and jury.  Yet I tell you that there are exceptions.
There are certain men in England who would never be brought before a
criminal court.  I am one of them."

At first I was inclined to regard Kirk as a madman, yet on looking into
his face I saw an expression of open earnestness, and somehow I felt
that he was telling me the curious truth.

"I certainly thought there were no exceptions," I said.

"I am one of the few," he replied.  "They dare not place me in a
criminal dock."

"Why?"

"For certain reasons"--and he smiled mysteriously--"reasons which you,
if you become my friend, may some day discover.  I live here in this
by-road of a London suburb, but this is not my home.  I have another--a
long way from here."

And, turning from me suddenly, he addressed questions to Joseph, asking
him his opinion of me.

"Where's your coat?" screeched the bird.  "Where's your coat?  Good
night!"

The whole scene was strangely weird and incongruous.  Kirk at one moment
speaking of a remarkable tragedy and at the next chaffing his pet.

At last, however, I fixed my host to the point, and asked him straight
out what had occurred.

"Well," he said, placing down his pipe and resting His protruding chin
upon his right hand, as he gazed across at me, "just follow me for a few
moments, and I'll describe, as best I can, all that is known of the
affair--or, rather, all I know of it.  Do you happen to know Sussex
Place, Regent's Park?"

I replied in the affirmative.  It was, as you probably know yourself, a
highly respectable crescent of large houses overlooking the park.
Entrance was gained from the road in the rear, for the houses faced the
park, perhaps one of the pleasantest rows of residences in London.  The
occupiers were mostly City merchants or well-to-do ladies.

"Well," he said, "in one of those houses there has lived for the past
five years or so Professor Ernest Greer, the well-known chemist, who,
among other appointments, holds the Waynflete Professorship of Chemistry
at Oxford University.  Though his age is only about fifty-five, his
whole career has been devoted to scientific research, with the result
that he has amassed a considerable fortune from royalties gained from
the new process he patented four years ago for the hardening of steel.
I dare say you've often seen his name mentioned in the papers.  He was a
most popular man, and, with his daughter Ethelwynn, often went into
society.  In addition to the Regent's Park house, they had a pretty
seaside cottage down at Broadstairs."

"I've seen the Professor's name very often in the papers," I remarked,
"in connection, I think, with the British Association.  I read, not long
ago, an account of one of his interesting lectures at the London
Institution."

"Then you realise his high standing," said Kirk, interpolating an aside
to Joseph.  "Well, Mrs. Greer is dead, and the household at Regent's
Park consists of the Professor, Ethelwynn, her maid Morgan, two
housemaids, a female cook, and the butler Antonio Merli, an elderly
Italian, who has been in the Professor's service for nearly twenty
years.  On the evening before last--that was Sunday--at twenty minutes
to five o'clock, the Professor and his daughter were together in the
large upstairs drawing-room, which overlooks the park, where Antonio
served tea.  Five minutes later Antonio re-entered and handed his master
a telegram.  The Professor, having read it, placed it upon the fire, and
remarked that he would be compelled to go to Edinburgh that night by the
11:30 from King's Cross, but would return in three days' time, for the
girl had accepted an invitation for the grand ball at Sutherland House
to-morrow."

"The Professor sent no reply to the message?"  I asked, much interested.

"No; but half an hour later his actions struck his daughter as somewhat
peculiar, for, having suddenly glanced up at the clock, he rose, crossed
to one of the three long windows--the end one--and drew up the blind.
Then, after a pause, he lowered it again.  Then twice he pulled it up
and down quickly, and returned again to where he was sitting.  At least,
that is his daughter's story."

"He signalled to somebody--using the Morse code, I should say."

"Exactly my theory, Mr. Holford.  I note that you follow me," exclaimed
the friendless man.  "You possess a keen sense of deduction, I see!"

"Apparently you don't believe this statement of Miss Ethelwynn's?"  I
said.

He sniffed quickly, but did not at first reply.

"The fact that he drew the blinds up and down at a preconcerted hour
shows that he communicated with somebody who was awaiting the signal
outside in Regent's Park," he remarked at last.

"Well, what then?"

"At eight he dined, as usual, with his daughter, and after dinner the
faithful Antonio packed his kit-bag and suit-case, putting in only
sufficient clothes for a stay of three days.  At her father's order
Ethelwynn telephoned to the station-master's office at King's Cross and
secured a sleeping berth in the 11:30 express for Edinburgh.  At a
quarter to eleven o'clock he kissed his daughter good night, and went
away in a cab to the station, promising faithfully to be back to take
her to the ball."

"And he disappeared--I suppose?"

"No, he didn't," my companion exclaimed, as, turning to the bird, he
said, "Mr. Holford jumps to conclusions just a little too quickly,
doesn't he, Joseph?"  And he slowly relit his pipe, which had again gone
out.

"First," he went on, "let me tell you of the arrangement of the
Professor's house.  The whole of the ground and first floors are devoted
to reception rooms.  The remaining two floors and attics are bedrooms.
Now, on the first floor, reached by passing through what is known as the
Red Room, a small boudoir at the back, and then through a short passage,
one comes to a large and spacious studio, an addition made by a former
owner, a well-known artist.  The only entrance is through the Red Room.
The Professor rented the house on account of this studio, and had it
fitted up as a laboratory.  Here, secure from intrusion, he frequently
carried on his experiments, making those remarkable discoveries which
have rendered him world-famous.  The laboratory is shut off from the
boudoir by this short passage, there being two doors, one in the boudoir
itself and one at the entrance to the Professor's workshop.  To both
these doors are patent locks, of which the Professor keeps the keys,
carrying them upon his watch-chain.  No one else has a key, while the
door from the conservatory over the porch is walled up.  This is in
order that no prying person shall enter in his absence and discover what
experiments are in progress--a very natural precaution."

"Then they were secret experiments he was making?"  I remarked.

"Yes.  And now for the mysterious sequence of facts.  They are as
follows: Next morning, when the servants opened the house, one of the
maids found, lying upon the hall table, a note addressed to Miss Greer.
When Ethelwynn opened it, she found it to be from her father, telling
her with regret that he must be absent abroad for several months, but
that she was not to feel uncomfortable, and giving her certain
directions, as well as how to obtain money during his enforced absence."

"Well?"

Joseph, the parrot, set up a loud screeching, trying to attract his
master's attention.

"Two hours later Antonio discovered upon the stairs leading up to the
drawing-room a curious little gold and enamel charm in the form of a
child's old-fashioned wooden doll--a beautifully-made little thing," he
went on; "and half an hour later a maid, while cleaning the boudoir
outside the locked door giving entrance to the laboratory, was surprised
to find a small spot of blood upon the white goat-skin mat.  This seems
to have aroused Antonio's apprehensions.  A telegram to the Professor at
the North British Hotel in Edinburgh, sent by his daughter, brought,
about three o'clock in the afternoon, a reply stating that he was quite
well, and it was not until seven o'clock last evening that Ethelwynn
communicated with me, her father having suggested this in the note she
had received.  I called upon her at once, and was shown the note, the
little golden doll, and the ugly stain upon the mat.  By then my
curiosity became aroused.  I went out to a telephone at a neighbouring
public-house, and, unknown to anybody, got on to the reception clerk at
the North British Hotel in Edinburgh.  In answer to my inquiry, the
young lady said that during the day a telegram had arrived addressed to
Professor Greer, and it had been placed upon the board where telegrams
were exhibited.  Somebody had claimed it, but no one of the name was
staying in the hotel."

"You have now said that the Professor was your friend," I remarked.  "I
understood you to say that he was an enemy."

"I'll explain that later," said my companion impatiently, drawing hard
at his pipe.  "Let me continue to describe the situation.  Well, on
hearing this from Edinburgh, I drove to King's Cross, and, somewhat to
my surprise, found that Professor Greer had left London by the train he
had intended.  The sleeping-car attendant who had travelled with him up
North was just back, and he minutely described his passenger, referring
to the fact that he refused to have an early cup of tea, because tea had
been forbidden by his doctor."

"A perplexing situation," I said.  "How did you account for the
bloodstain?  Had any of the servants met with an accident?"

"No, none.  Neither dog, nor cat, nor any other pet was kept, therefore
the stain upon the mat was unaccountable.  It was that fact which caused
me, greatly against Miss Ethelwynn's consent, to seek a locksmith and
take down the two locked doors of the laboratory."

And he paused, gazing once more straight into the flames, with a curious
expression in those deep-set brown eyes.

"And what did you find?"  I eagerly inquired.

"I discovered the truth," he said in a hard, changed tone.  "The doors
gave us a good deal of trouble.  At the end of the laboratory, huddled
in a corner, was the body of the Professor.  He had been stabbed to the
heart, while his face presented a horrible sight, the features having
been burned almost beyond recognition by some terribly corrosive fluid--
a crime which in every phase showed itself to be due to some fiendish
spirit of revenge."

"But that is most extraordinary!"  I gasped, staring at the speaker.
"The sleeping-car conductor took him to Edinburgh!  Besides, how could
the two doors be locked behind the assassin?  Were the keys still upon
the victim?"

"They are still upon the dead man's watch-chain," he said.  "But, mark
you, there is still a further feature of mystery in the affair.  After
her father's departure for the station, his daughter put on a
dressing-gown and, sending Morgan to bed, seated herself in her
arm-chair before the fire in the Red Room, or boudoir, and took a novel.
She read until past four o'clock, being in the habit of reading at
night, and then, not being sleepy, sat writing letters until a
drowsiness fell upon her.  She did not then awake until a maid entered
at seven to draw up the blinds."

"Then she was actually at the only entrance to the laboratory all the
night!"

"Within a yard and a half of it," said Kershaw Kirk.  "But the affair
presents many strange features," he went on.  "The worst feature of it
all, Mr. Holford, is that a motive--a very strong motive--is known to
certain persons why I myself should desire to enter that laboratory.
Therefore I must be suspected of the crime, and--well, I admit at once
to you I shall be unable to prove an alibi!"

I was silent for a moment.

"Unable to prove an alibi!"  I echoed.  "But the police have as yet no
knowledge of the affair," I remarked.

"No; I have, however, reported it in another quarter.  It's a most
serious matter, for I have suspicion that certain articles have been
abstracted from the laboratory."

"And that means--what?"

"It means, my dear sir, very much more than you ever dream.  This is at
once the strangest and the most serious crime that has been committed in
England for half a century.  You are a man of action and of honour, Mr.
Holford.  Will you become my friend, and assist me in trying to unravel
it?" he asked quickly, bending forward to me in his earnestness.

"Most certainly I will," I replied, fascinated by the amazing story he
had just related, quite regardless of the fact that he was the suspected
assassin.

I wonder whether if I had known into what a vortex of dread, suspicion,
and double-dealing that decision of mine would have led me I would have
so lightly consented to render my help?

I think not.

"Well," he said, glancing at his watch, "the place has not been touched.
If you consent to help me, it would be best that you saw it and formed
your own independent theory.  Would you care to come with me now?  You
could run along and make some excuse to Mrs. Holford."

The remarkable mystery, surrounding as it did one of the best-known
scientists in the land, had already gripped my senses.  Therefore I did
as he suggested, and about an hour later alighted from one of my own
cars at the portico of that house of tragedy.

A white-faced, grave-eyed man in black, the man Antonio, opened the door
in response to our ring, but on recognising my companion he gripped him
quickly by the arm, gasping:

"Ah, signore, I had just telephoned to you!  I had no idea you were
returning here to-night.  Madonna Santa, signore, it's terrible--
terrible!  Something else has happened.  The young lady--she's--"

"What do you mean?  What has happened now?" asked Kirk quickly.  "Tell
me; she's--what?"

But the old Italian could not speak, so overcome and scared was he.  He
only pulled my companion forward into the dining-room on the left, and
with his thin, bony finger pointed within.

And as I entered the big room my eyes fell upon a sight that staggered
me.

Like the old servant, I, too, stood aghast.

Truly Kershaw Kirk had spoken the truth when he had said that the
mystery was no ordinary one.

At that moment the problem seemed to me to be beyond solution.  It
already ranked in my mind as one of those mysteries to which the key is
never discovered.  Who _did_ kill Professor Greer?

CHAPTER THREE.

THE HOUSE OF MYSTERY.

What I saw in the house of Professor Greer on the night of that
fifteenth of January formed indeed a strange and startling spectacle.

Ah, I am haunted by it even now!

That sallow-faced man who had conducted me there was himself a mystery,
and upon his own confession was suspected of a foul crime.  Besides, it
was being kept rigorously from the police, which, to say the least, was
a proceeding most unusual.

What could it all mean?  Who was this Kershaw Kirk, this "dealer in
secrets," as he called himself, who was immune from public trial, even
though not immune from arrest and imprisonment?  The whole intricate
problem launched upon me during those past few hours held me in
fascination as nothing had ever held me before.

I could see that the man Antonio held Mr. Kirk in great fear or great
regard, for he was urbanity itself.

But what we saw within the fine, solidly-furnished dining-room, with its
carved buffet filled with antique shining silver, was so unexpected that
even my companion gave vent to an exclamation of amazement.  Upon the
dark carpet near the empty grate, her head pillowed upon a yellow silken
cushion, lay a very pretty, fair-haired girl of about twenty-two.  Her
hat was off, otherwise she was in walking dress, with a short fur jacket
and a fine blue fox boa, which, loosened, showed the delicacy of her
white throat.  Her face contour was bloodless; but all one side of her
face was swollen, disfigured, and white as marble.

"Great heavens!" cried Kirk, as he fell on his knees beside her and
grasped her hands.  "Why, look!  She's been disfigured, just as her
father has been!"  And he bent until his ear was against her heart.

"Get me that little mirror from the wall--over there, Mr. Holford.
Quick!" he urged.

I sprang to do his bidding, and he placed against her mouth the little
carved bracket wherein the square of looking-glass was set.  When he
withdrew it, it was unclouded.

"She may not be dead?"  I exclaimed.  "Shall I go for a doctor?"

"No," Kirk snarled; "we want no doctors poking their noses about here.
This is a matter which concerns only myself, Mr. Holford!"  And he bent
to the prostrate girl to make a more minute investigation in a manner
which showed me that he understood the various symptoms of death.

"As you know, signore," Antonio said, "Miss Ethelwynn left last night to
stay at her aunt's, Lady Mellor's, in Upper Brook Street, and I have not
seen her since, until ten minutes ago I chanced to enter here, when, to
my amazement, I found her lying just as you see her, except that I put
the pillow beneath her head before telephoning for you.  I didn't know
whom to call."

"You've told no one else of this?"  Kirk asked quickly.

"Only my brother, signore.  He's staying with me.  The girls have all
left, and Morgan, Miss Ethelwynn's maid, is at Lady Mellor's."

"Your brother!" repeated Kirk reflectively.

"Yes, signore.  He's here."  And a respectably-dressed man a trifle
younger than Antonio, who had been standing out in the hall, entered and
bowed.  "Pietro keeps a tobacconist's in the Euston Road," he explained.
"I asked him here, as I don't care to stay in this place alone just
now."

Kirk regarded the new-comer keenly, but made no remark.  His attention
was upon the unfortunate girl, who as far as we could gather, had
returned in secret, entered quietly with her latch-key, and removed her
hat, placing it upon the couch, sticking its pins through it, before she
had been struck down by some unseen hand.

There was no perceptible wound, and Kirk could not determine whether she
was still alive, yet he refused to summon medical aid.  I confess to
being somewhat annoyed at his obstinacy, and surprised at the secrecy
with which he treated the whole of the remarkable circumstances.  That
very fact tended to strengthen the suspicion that he himself knew more
about the crime than he had admitted.

Surely the police should be informed!

He was very carefully examining the girl's clothing, seeking to discover
a wound; but, as far as we could see, there was none, yet the pallor of
the countenance was unmistakably that of death, while the hard, white
disfigurement of the face was weird and horrible.  The eye was closed,
distorted, and screwed up by pain, and both mouth and ear seemed
shrivelled out of shape.

"Who's responsible for this, I wonder?" growled Kirk to himself.  "Why
did she wish to return here in secret--to the house wherein she knew her
father was lying dead?  There was some strong motive--just as there is a
motive for her death as well as her father's."  Then, looking up to me,
he added, "You know, Mr. Holford, this poor young lady was her father's
assistant and confidante.  She was in the habit of helping him in his
experiments, and making notes at his dictation of certain results."

I knelt at the other side of the inert, prostrate form, and took the
ungloved hands in mine.  The stiffening fingers were cold as ice.

"It's brutal--blackguardly!" cried Kirk in a frenzy of anger.  "Whoever
has thus sacrificed the girl's beauty deserves a dog's death.  The
motive in both cases must be vengeance.  But for what?"

Antonio and his brother were active in getting brandy, sal volatile,
ammonia, hot water, and other restoratives; but, though Kirk worked
unceasingly for half an hour in a manner which showed him to be no
novice, all was to no purpose.

There was no sign of life whatever.  Indeed, the colour of the
disfigured portion of the fair countenance seemed to be slowly changing
from marble-white to purple.

Kirk watched it, held his breath, and, staying his hand, shook his head.

"Why don't you call a doctor?"  I again urged.  "Something may be done,
after all.  She may not be dead!"

"I can do all that a doctor can do," was his calm, rather dignified
reply, and I saw by the dark shadow upon his brow that he was annoyed at
my suggestion.

So I straightened myself again and watched.

At last my eccentric companion came to the conclusion that no more could
be done for the unfortunate girl, and we all four lifted her from the
carpet on to the large leather sofa set near the window.

Then Kirk led the way up the broad, thickly-carpeted staircase to the
floor above.  Entering an open door leading from the square landing, he
touched an electric switch, revealing a small elegantly-furnished room,
a boudoir, upholstered in dark red silk.  The walls were enamelled dead
white, relieved by a beading of gold, and set in the panels were two
fine paintings of the modern Italian school.

The red room was a veritable nest of luxury, with low easy chairs, a
cosy corner near the fire, and a small reading table, whereon stood a
selection of the latest novels from the library.  In the cosy corner I
noticed that the cushions were crushed, just as they had been left by
the unfortunate girl as she had been aroused from her sleep by the
entrance of the maid at early morning.

One side of the room was occupied by a big bay window of stained glass,
that probably faced a blank wall, while about four feet to the right of
the cosy corner was a closed white-enamelled door--the door which gave
entrance to the passage leading to the laboratory.  The carpet was a
pale grey, with a wreath of small roses running round the border, and
before the door lay the white goatskin mat.  My companion pointed to it,
and I saw there the tell-tale stain of blood.  The fire had been left
just as it had died out on the morning of the tragedy.

"You see," Kirk said, advancing to the closed door which led to the
laboratory, "there is here a patent lock--an expensive make, which has
but one key.  This door I found still locked!"

Opening it, we passed into a short passage about twelve feet long,
closed by a similar door.  This also he reopened, and I found myself in
a large long apartment, very lofty, and well lit by a long high window
along the side towards the street and at the end, while a skylight
occupied part of the roof.

Upon rows of shelves were many bottles of chemicals, retorts, and
delicate experimental apparatus, while on the right was a small furnace.
There were also three zinc-covered tables with the miscellaneous
accumulation of objects which the owner of the place had been using.  I
saw a blocked-up door on the right, which my companion explained let
into the conservatory over the portico.

"Look!" whispered my friend in a low voice.  "This way."  And he
switched on the lights at the further end of the great high apartment.

I stepped forward at his side, until I distinguished, huddled up in the
further corner, a human figure in dark grey trousers and black
frock-coat.  It seemed as though he had been propped in the corner, and
his grey head had fallen sideways before death.

I went further forward, holding my breath.

The victim was apparently nearly sixty, with hair and moustache turning
white, rather stoutly built, and broad-shouldered.  His position was
distorted and unnatural, as though he had twisted himself in the final
agonies of death.  The thin waxen hands were clenched tightly, and the
linen collar was burst from the neck, while the Professor's dark blue
fancy vest bore a stain where the assassin's knife had struck him
unerringly in the heart.

Of his features I, a stranger, could distinguish but little, so swollen,
livid, and scarred were they that I was instantly horrified by their
sight.  The disfigurement had been so terrible that there remained
hardly any semblance to a human face.

"Well," exclaimed Kirk at last, "you have seen it!  Now what is your
opinion?"

We were standing alone in the great laboratory, for Antonio and his
brother had remained downstairs at my companion's suggestion.

I looked round that great silent workshop of one of the most
distinguished chemists of the age, and then I gazed upon the mortal
remains of the man upon whom so many honours had been showered.  Warped,
drawn, crouching, with one arm uplifted almost as though to ward off a
blow, the body remained a weird and ghastly object.

"Has it been moved?"  I inquired when I recovered speech.

"No; it is just as we found it--just as the unknown assassin left it,"
he said.  "The disfigurement, as far as I can judge, has been caused by
some chemical agency--some acid or other substance placed upon the face,
with fiendish cruelty, immediately before death."

I bent closer to the lifeless face in order to examine it, and
afterwards agreed with him.  It was undoubtedly a murder prompted by a
fierce and bitter vengeance.

"The work of a madman, it may be," I suggested.

But Kershaw Kirk shook his head, saying: "Not of a madman, but of a very
clever murderer who has left not a trace of his identity."

"Do you think that the Professor was struck down at the spot where he
now is?"  I asked, for my friend seemed to be something of an expert in
the habits of the criminal classes.

"I think not.  Yet, as you see, the place is in no way disordered.
There is no sign whatever of a struggle."

I looked around, and as far as I could discern everything was as it
should be.  Upon the nearest table in the centre was a very delicate
glass apparatus in which some experiments had recently been made, for
certain yellowish liquids were still within.  Had this table been
violently jarred, the thin glass tubes would have been disarranged and
broken, a fact which showed conclusively that the fatal blow had been
struck with great suddenness and in silence.

It had not occurred to Kirk to examine the dead man's pockets before,
and now, kneeling at his side, he was in the act of doing so.

The various objects he took out, first examined, and afterwards handed
them to me.  There were several letters, none of any great importance,
some chemical memoranda scribbled in pencil upon a piece of blank paper,
a gold presentation watch and chain, fifteen pounds odd in money, and a
few minor trifles, none of which threw any light upon the mysterious
tragedy.

My companion made another careful examination of the body.  Then, rising
to his feet, he walked slowly around the laboratory, in further search,
it seemed to me, of anything that the assassin might have left behind.
But by his countenance I saw that this eccentric man who dealt in
secrets, as he had admitted to me, was much puzzled and perplexed.  The
enigma was complete.

So complicated and extraordinary were the whole circumstances that any
attempt to unravel them only led one at once into an absolute
_cul-de-sac_.

To whom had the dead man signalled in the Morse code by raising and
lowering the blind?

Someone, friend or enemy, had been waiting outside near Clarence Gate in
Regent's Park in the expectation of a message.

He received it from the Professor's own hands, those hands which before
the dawn were cramped in the stiffness of death.

CHAPTER FOUR.

A SILENT MESSAGE.

For a full hour we remained there in the presence of the dead.

Before that huddled figure I stood a dozen times trying to form some
feasible theory as to what had actually occurred within that room.

The problem, however, was quite inexplicable.  Who had killed Professor
Greer?

There, upon the end of the unfortunate man's watch-chain, were the two
keys which he always carried, keys which held the secrets of his
experiments away from the prying eyes of persons who were undesirable.
Many of his discoveries had been worth to him thousands of pounds, and
to public companies which exploited and worked them hundreds of
thousands of pounds more.  There, in that very room in which I stood,
had the Greer process of hardening steel been perfected, a process now
used in hardening the armour-plates of our newest Dreadnoughts.  Yet the
master brain which had thought out those various combinations, and by
years of patience had perfected the result, was now before me, inactive
and dead.

I shuddered at sight of that disfigured face, hideous in its limp
inertness and horrible to the gaze.  But Kershaw Kirk, his eyes narrower
and his face more aquiline, continued his minute investigation of every
object in the room.  I watched him with increasing interest, noticing
the negative result of all his labours.

"I shall return again to-morrow when it is light," at last he said;
"artificial light is of little use to me in this matter.  Perhaps you'll
come with me again--eh?"

"I'll try," I said, though, to be candid, I was not very keen upon a
second visit to the presence of the disfigured body of the Professor.  I
could not see why Kirk was so anxious to avoid the police and to keep
the affair out of the papers.

"The body must be buried before long," I remarked.  "How will you obtain
a medical certificate and get it buried by an undertaker?"

"Mr. Holford," he said, turning to me with an expression of slight
annoyance upon his face, "I beg of you not to anticipate difficulty.  It
is the worst attitude a man can take up--especially in trying to solve a
problem such as this.  The future kindly leave entirely with me."

At that moment I was fingering a small test-tube containing some thick
grey-coloured liquid, and as I turned I accidentally dropped it upon the
tiles with which the Professor had had the place paved.  In an instant
there was a bright flash, almost like a magnesium light, so brilliant
that for a second we were both blinded.

"I wonder what that was?" he remarked, startled by the result.  "One
must be careful in handling what the dead man has left behind."

"Evidently," I said; "we cannot tell what these various experimental
apparatus and tubes contain.  Therefore we should handle them
delicately."

And I bent to the table to examine another tube containing some bright
red crystals held over an extinguished spirit-lamp by a brass holder, an
action which my companion, I noticed, watched with a curious expression.

Was it suspicion of myself?

"Well, my dear friend," he exclaimed suddenly as he stood beside the
table, "the problem is, as you see, rendered the more difficult of
solution by the inexplicable fate which has overtaken the Professor's
daughter.  Here is a man against whom, as far as we know, nobody in the
world had a grudge, who receives a telegram which he is careful to
destroy, makes a preconcerted signal at his drawing-room window, and
goes upon a journey to Edinburgh.  We know that he went, for the
conductor recollects asking if he would take an early cup of tea.
Again, he received his daughter's telegram and replied to it.  Yet at
the same time he was in Edinburgh he was in this very room behind two
locked doors of which he alone had the key, the victim of a brutally
murderous attack!  These doors were locked, and to enter here both he
and the assassin must have passed through the boudoir within a yard or
so of his daughter."

"Is there no other means of access except through the boudoir?"  I
asked.  "Have the windows been examined?"

"Yes; all the windows were screwed down on the inside.  To-morrow, in
the light, you shall satisfy yourself.  I must come here to search for
any finger-prints," was his hasty reply.  "When I caused these doors to
be opened, I was careful not to allow the locksmith to see that any
tragedy had occurred.  The man was paid, and went away in ignorance.
Yet when Miss Ethelwynn realised the truth she was as one demented.  At
first she refused to leave the place, but I persuaded her, and she went
with her maid to her aunt's.  I impressed upon her the value of silence,
and she gave me her word that she would say nothing of what had
occurred."

"What about her maid Morgan?"

"She is ignorant of the truth," he said, with a grim smile.  "Well, this
evening, it appears, the dead man's daughter returns in secret, enters
with her latch-key the house where her father is lying, removes her hat
carefully, and then--"

"Yes," I said.  "And then?  What do you believe occurred?"

He was silent, his deep-set eyes downcast in thought.

"Well, I--I hardly know what to think," he declared.  "It almost seems
as though she shared the same fate as her father.  That horrible
disfiguration is most remarkable."

"Her entry here in secret and the strange fate that has overtaken her
increases the mystery tenfold!"  I declared.  "Why didn't she call
Antonio?"

"Perhaps that was her intention, but she was prevented," suggested my
friend.  And I saw that his glance was fixed upon me curiously, as
though he were deliberately gauging my character and intelligence.

"But to me it appears as though her intention might have been to reach
the laboratory unobserved," I said.  "She may, indeed, have been up here
for aught we know to the contrary."

"I hardly think so.  She was far too horrified at sight of the body of
her father, to whom she was so devoted.  The scene when she saw him dead
was very painful."

"But might she not have been induced to return by morbid curiosity?"  I
suggested.

"You've already told me that she was beside herself with grief."

"Well," he replied, with a sigh and a final glance across to where the
dark object was huddled in the opposite corner, "no purpose, I think,
can be served by remaining here longer to-night.  We must return in the
morning.  I only brought you here in order that you might fully
understand the exact problem now before us.  Come along."

"But I don't see, Mr. Kirk, how it is possible for me to help you.  I'm
quite a novice in this kind of thing," I said.

"You are not a detective.  If you were, I should not seek your aid," he
snapped, as he led the way to the door and switched off the lights.  "I
know you think it rather strange that I have not called a doctor and the
police, and had a post-mortem, and allowed the newspaper reporters to
`work up' a big sensation; but, as I've already told you, our success
depends upon absolute secrecy.  The affair is a startling one to you, no
doubt; but if you were aware of what the tragedy really means you would
be dumbfounded.  Why, the newspapers could make a world-wide sensation
of it if only they got at the true facts; but they never will, I assure
you--never."

"Then even I may not know the true facts?"  I asked, as I stood with him
again in the boudoir.

"As far as the tragedy is concerned, you already know them.  They are
just as I have told you.  But there are other facts--facts concerning
myself and also the Professor--which I am not permitted to divulge.
They must," he added, "remain a secret."

"Well--if you are not perfectly frank with me, Mr. Kirk," I protested,
"I cannot see how I can regard you as a sincere friend.  This is a
serious and complicated problem, in which you require my assistance in
an endeavour to seek a solution.  How can I form any conclusions or help
you if you deliberately hold back from me some of the circumstances?"

"I have held back none," was his hasty response--"at least, none which
have any bearing whatever upon the tragedy.  It is of myself and my own
connection with Greer that I am speaking.  I was the first person
called, before there was even a suspicion of anything wrong.  The fact
is, the dead man trusted me implicitly."

"And, according to your showing, certain enemies of yours suspected the
truth--that your friendship for the Professor was only feigned."

My companion looked me straight in the face with his narrow-set eyes,
and replied:

"My dear Mr. Holford, what my enemies say was, I admit, perfectly
correct.  I have sought to conceal nothing.  Greer believed that I was
his friend, but I hated him.  I had good cause to do so!"

The man's crafty eyes again met mine, and I saw in them an expression
which I had never noticed before.  Was it possible that he was the
unknown assassin, and was only misleading me by clever and cunning
devices?

I recollected that he had told me that the Professor had stolen from him
some valuable secret.  Well, if he did not fear the crime of retaliation
being brought home to him, why did he not go openly and lay the facts
before the police?  His evasive replies and thin excuses appeared to be
utterly ridiculous.  In my foolish ignorance I still believed Kershaw
Kirk to be an ordinary individual, much like myself.  The remarkable
truth had not then been revealed to me--as it was later.

We descended to the dining-room, where Antonio and his brother Pietro
were still watching beside the couch whereon lay the poor girl who had
met with such a strange and inexplicable fate.

Kirk again knelt beside her, and for a long time searched for any wound
she might bear.  But he found none.

"Remember, Antonio, no person must enter this house under any pretext
whatever," my companion ordered.  "You are responsible."

"No one shall know anything, signore," replied the man.  "Morgan and the
maids are all in ignorance--for you, signore, kept it so cleverly from
them."

"A woman never can keep a secret," Kirk answered sharply, "and if we are
to fathom the mystery of your master's death not a word must leak out.
You know what I have told you."

"I recollect, signore," the man replied.  And, using the Italian oath,
he said, "I have promised you, upon the tomb of my sainted mother."

"Then close this room, and with your brother keep a watchful vigil until
to-morrow."

And we both went out, and were soon running in the car back towards
Bedford Park.

Arrived at his house, he insisted that I should enter for a "night-cap,"
it being then just past three o'clock.  Therefore, reluctantly, I
accompanied him within.

In his study a tantalus-stand and glasses were upon the table.  He had
thrown off his overcoat, and was about to pour me out some whisky, when
the telephone bell suddenly rang.  He put down the glass, and, walking
to the instrument, answered the summons.

"Hulloa?  Yes?" he said.

Then, as he listened intently, his face blanched.  He spoke some quick
words in German, which, unfortunately, I could not follow.  They seemed
like instructions.

Again he listened, but suddenly whatever he heard so appalled him that
the receiver dropped from his thin, nerveless fingers, and with a low,
hoarse cry he staggered across to his big grandfather chair, near which
I was standing, and sank into it, rigid, staring, open-mouthed.

If ever guilt were written upon a man's face, it assuredly was written
upon that of Kershaw Kirk at that moment.

CHAPTER FIVE.

CERTAIN SUSPICIONS STRENGTHENED.

To Mabel, my wife, I said nothing.  In the circumstances, I deemed
silence golden.

Kirk's attitude at the telephone had filled me with suspicion.

During the hours I spent in bed before the dawn I lay thinking.  The
problem was utterly inexplicable, the more so now that the dead man's
daughter was also dead.

I was convinced, as I lay there in the darkness, that there was
something very suspicious in the fact that Kirk, who seemed to rule the
household, would not allow the police to have any knowledge of what had
occurred.  Indeed, my own position was somewhat unenviable, for, being
aware that a murder had been committed, was I not legally bound to give
information?  Was I not liable to prosecution if I failed to do so?

The mystery surrounding Kershaw Kirk had increased rather than
diminished in that final quarter of an hour I had spent with him as he
had sat staring straight into the fire, uttering scarce a word.

What had been told him over the telephone had caused an entire change in
his manner.  Previously he had been dictatorial and defiant.  He was now
cringing, crushed, terror-stricken.

The grim scenes I had witnessed surged through my brain.  The mystery of
it all had gripped my senses.  Carefully I analysed each event, trying
to discern some light as to its cause and motive.  But I was not a
professional detective.  This was the first time I had found myself
mixed up in a crime by which human life had been lost.

That the death of Professor Greer was no ordinary crime of violence I
had quickly recognised.  There was some subtle motive both in the crime
itself and in the supposed presence of the Professor in Edinburgh,
whereas in reality he was already lying dead in his own laboratory.

Those instructions to his daughter, which seemed to have been written
after his departure from King's Cross, also formed an enigma in
themselves.  The dead man had actually sought the assistance of his
worst enemy!

Yet, when I weighed the circumstances as a whole calmly and coolly, I
saw that if the unknown person to whom the Professor had signalled on
that fateful night could be found a very great point would be gained
towards the solution of the problem.

The pulling up and down of the drawing-room blind was, no doubt, in
order to inform some person waiting without of his journey north.  Was
that person who received the signal afterwards the assassin?

Yet the fact that the crime was committed behind locked doors, that both
the victim and the assassin had to pass within a few feet of where Miss
Ethelwynn was seated, and that into the unfortunate Professor's face
some terribly corrosive fluid had been dashed, formed a problem which
held me mystified.

There was something uncanny in the whole inexplicable affair.  I now
realised for the first time how complete was the mystery of the
Professor's death, even apart from the other facts of his signals and
his journey north.

Kirk, this dealer in secrets, admittedly posed as a friend of the
family.  Greer trusted him.  To him Ethelwynn had fled for assistance at
the first suspicion of anything being wrong.  Therefore would it not
have been easier for him than for anyone else to enter the house in
secret and kill the man who had stolen from him that mysterious secret?

Yet, try how I would, I was unable to rid myself of the grave conviction
that my new acquaintance was cognisant of more than he had told me.  He
was naturally a reserved man, it was true; yet there was an air of
cosmopolitanism about him which spoke mutely of the adventurer.

His refusal to allow a doctor to see the Professor's daughter was
nothing short of culpable.  Had Antonio, that sly, crafty Italian, to
whom I had taken such instinctive dislike, summoned a doctor at once, it
was quite possible that the poor girl's life might have been saved.

But why had she returned to the house in a manner so secret?  Why had
she crept into the dining-room and removed her hat?  It would almost
seem as though she had returned for good, for if she had intended to go
back to her aunt's she would not have taken off her hat and laid it
aside.

And why had she done so in the dining-room, of all places?  Why had she
not ascended to her own room?  And why, most of all, had she not
summoned Antonio?

Was it because of fear of him?

Kirk and Antonio were friends.  That I had detected from the very first.
The Italian was polite, urbane, servile, yet I saw that the bow was
only a shallow make-believe.  Alone together, the pair would, no doubt,
stand upon an equal footing.

The reason she had returned home was mysterious enough, yet the greater
problem was the reason why she also had been struck down and the same
corrosive liquid flung into her fair countenance.

I could not think that Kirk was responsible for this second
assassination, for, unless Antonio had lied, it had been committed at
the very hour when I had been seated with my mysterious neighbour only a
few doors away from my own house.

So, as you may readily imagine, I was still sorely troubled when at last
the maid brought me my hot water and I rose to dress.

I quite saw now that the reason why Kirk had called to inspect the new
Eckhardt tyre was merely in order to make my acquaintance.  Yet it was
certainly curious that he should have predicted the visits of the two
other men for the same purpose.  After breakfast I went, as usual, to
the garage, but my mind was still full of the events of the previous
night.

Kirk had arranged to call for me at eleven and return to Sussex Place,
where he intended to search for any finger-marks left by the assassin.
Eleven o'clock struck, but he did not arrive.  In patience I waited
until one, and then returned home to luncheon, as was my habit.

His non-arrival confirmed my suspicions.  What, I wondered, could have
been the purport of that mysterious message in German that he had
listened to on the telephone just before we had parted?

At two o'clock I called at his house and rang the door-bell.  There was
no response.  Both Kirk and his sister were out.

So I returned to the garage, and with Dick Drake, my stout, round-faced,
dare-devil driver, who held two records at Brooklands, and was
everlastingly being fined for exceeding the speed limit, I worked hard
upon the refractory engine of a car which had been sent to me for
repair.

All day it was misty, but towards evening the fog increased, until it
became thick even in Chiswick, therefore I knew that it must be a
regular "London particular" in the West End.  One driver, indeed, who
had come in from Romford, said he had taken four hours to cross London.
Hence I resolved to possess my soul in patience and spend a quiet
evening at home with my wife and her young sister, who lived with us.

Curiously enough, however, I found myself, towards six o'clock, again
seized by a sudden and uncontrollable desire to return to Sussex Place
in search of my mysterious neighbour.  I felt within me a keen,
irrepressible anxiety to fathom the curious problem which that shabby
man, who declared himself immune from trial in a criminal court, had
placed before me.  Who could he be, that, like the King himself, he
could not be brought before a judge?

At times I found myself laughing at his absurd statements, and regarding
them as those of a lunatic; but at others I was bound to admit that his
seriousness showed him to be in deadly earnest.

Well, to cut a long story short, at eight o'clock I took Dick Drake and
managed to creep over in the fog to Regent's Park on one of the small
cars.

The door was opened, as before, by Antonio, who perceptibly started when
he recognised me.

Yes, Mr. Kirk was there, he admitted, and a few seconds later he came to
me in the hall.

He was a changed man.  His face was thinner, sallower, more haggard, and
the lines about his mouth deeper and more marked; yet he greeted me
affably, with many apologies for not keeping his appointment.

"I was here, very busy," he explained.  "I rang you up twice on the
'phone, but each time you were engaged."

"Well," I asked, going straight to the point, "what have you
discovered?"

"Very little," he said.  "I've searched all day for finger-prints, but
up to the present have found none, save those of Antonio, Ethelwynn, and
members of the household."

"You do not suspect any of the servants?"  I whispered, full of
suspicion of the crafty-looking Italian.

"Of course not, my dear sir.  What motive could they have in killing
such an excellent, easygoing master as the Professor?"

"Revenge for some fancied grievance," I suggested.

But he only laughed my theory to scorn.

I followed him upstairs, through the red boudoir to the laboratory, to
which the fog had penetrated, and there watched him making his test for
recent finger-prints.  His examination was both careful and methodical.
He drew a pair of old grey suede gloves over his hands, and, taking up
one after another of the bottles and glass apparatus, he lightly coated
them with some finely powdered chalk of a grey-green colour, afterwards
dusting it off.

On one or two of the bottles prints of fingers were revealed, and each
of these he very carefully examined beneath the light, rejecting them
one after the other.

To me, unacquainted as I was with the various lines of the finger-tips,
all looked alike.  But this shabby, mysterious neighbour of mine
apparently read them with the utmost ease, as he would a book.

In its corner, in the same position in which we had left it on the
previous night, lay the hideous body of the Professor, crouching just as
he had expired.  But Kershaw Kirk worked on, heedless of its presence.

I remarked to him that he was a careful and painstaking detective,
whereupon he straightened his back, and, looking me in the face, said:

"Please don't run away with the idea that I'm a detective, Mr. Holford.
I am not.  I have no connection whatever with the police, whom, I may
tell you, I hold in contempt.  There's far too much red-tape at Scotland
Yard, which binds the men hand and foot and prevents them doing any real
good work.  Look at the serious crimes committed in London during the
past three years to the perpetrators of which the police have no clue!
The whole police system in London is wrong.  There's too much
observation upon the speed of motor-cars and too little latitude allowed
the police for inquiry into criminal cases."

"Then you are not a police officer?"  I asked, for within the last few
hours I had become suspicious that such was the fact.

"No, I am not.  The reason I am inquiring into the death of Professor
Greer is because, for the sake of my own reputation, and in order to
clear myself of any stigma upon me, I must ascertain the truth."

"And only for that reason?"  I queried.

He hesitated.

"Well--and for another--another which must remain a confidential matter
with myself," he replied at length.  "The Professor was in possession of
a certain secret, and my belief is that this secret was stolen from him
and his mouth afterwards closed by the thief."

"Why?"

"Because, had the unfortunate man spoken, certain complications, very
serious complications, involving huge losses, would have accrued.  So
there was only one way--to kill poor Greer!  But the manner in which
this was accomplished is still an absolute enigma."

"Has it not struck you that the telegram sent from Edinburgh may have
been despatched by the assassin?"  I asked.

But he was uncertain.  He had as yet, he said, formed no theory as to
that portion of the problem.

"Where is the unfortunate girl?"  I asked, for I had noticed that she
was not in the dining-room.

He looked at me quickly, with a strange expression in his peculiar eyes.

"She's still here, of course," he declared.  "That second phase of the
mystery is as complicated as the first--perhaps even more so.  Come with
me a moment."

I followed him through the boudoir and into the study, where, opening a
long cupboard in the wall, a small iron safe was revealed, the door of
which opened at his touch.

"Here," he explained, "the Professor kept the valuable notes upon the
results of his experiments.  The safe was closed when I first called,
but this morning I found it open, and the contents gone!"

"Then the person who killed Professor Greer was not the thief!"  I
remarked.

"Unless he returned here afterwards," was Kirk's reply, with his eyes
fixed upon mine.

Then he glanced at his watch, and without a word turned upon his heel
and passed out of the room.

CHAPTER SIX.

A FURTHER MYSTERY.

I stood awaiting his return for a few moments, and then followed him out
upon the landing, where my feet fell noiselessly upon the thick Turkey
carpet.  Almost opposite, across the open staircase, I could see into
the large drawing-room, and there, to my amazement, I saw Kirk raising
and lowering one of the blinds.

He was making the same signal to someone outside in the park as that
made by the Professor before his death!

I slipped back to the study, much puzzled, but in a few moments he
returned, smiling and affable.

What signal had he made--and to whom?  It was foggy outside, therefore
the watcher must have been in the close vicinity.

Antonio appeared at the door, whereupon Kirk gave the manservant certain
instructions regarding the payment and discharge of the servants.
Apparently one of them had returned and asked for her wages in lieu of
notice.

"Be liberal with them," urged my companion.  "We don't want any
grumbling.  There is no suspicion as yet, and liberality will disarm
it."

"Very well, signore," replied the man, "I will pay them all and get rid
of them as soon as possible."

"Yes, at once," Kirk snapped, and the man went down the stairs.

"Well," I asked, after he was out of hearing, "what do you intend doing
now?"

"I never set out any line of action.  In such a case as this any such
method is folly," he replied.

"But at least you will do something with the bodies of the victims?
They must be buried," I exclaimed, for the gruesomeness of it all was
now preying upon me.  This was the first time that I had ever been
implicated in a murder mystery--_and such a mystery_!

"The disposal of the bodies is my own affair, Mr. Holford," he said
quietly.  "Leave that to me.  As far as the world knows, Professor Greer
and his daughter are away visiting."

"But Lady Mellor!  Is she not anxious regarding her niece's
whereabouts?"

"Lady Mellor is on the Riviera.  Her house in Upper Brook Street is in
charge of servants, therefore she is unaware that anything extraordinary
has transpired."

"Your only confidant is Antonio?"

"And your own self," he added.  "But have I not already impressed upon
you, my dear friend, the absolute necessity of secrecy in this affair?"

"You have given me no actual reason," I demurred.

"Because certain circumstances bind me to secrecy," was his reply.
"From what I have already told you I dare say you have gathered that I
am no ordinary individual.  I am vested by a high authority with a power
which other men do not possess, and in this case I am compelled to
exercise it."

He saw the look of disbelief upon my countenance.

"Ah," he laughed, "I see you doubt me!  Well, I am not surprised; I
should do so were I in your place.  But, believe me or not, Mr. Holford,
you will lose nothing, by assisting me in this affair and performing a
secret service for the high authority who must be nameless, but whose
trusted agent I am--even though the onus of this strange tragedy may be
cast upon me."

"The whole affair is a mystery," I remarked--"an inscrutable mystery."

"Yes," he sighed, "one that has been rendered a hundredfold more
inscrutable by a discovery made to-day--the discovery which prevented me
calling upon you at eleven o'clock.  But remain patient, trust in me,
assist me when I desire assistance, and it will, I promise, be well
worth your while."

For a moment I was silent.  Then, a trifle annoyed, I answered:

"My legitimate profession of motor-engineer pays me quite well, and I
think I prefer, with your permission, to retire from this affair
altogether."

"What!" he exclaimed.  "After giving me your promise--your word as a
gentleman!  Can't you see, my friend, that you can assist in furthering
the ends of justice--in fastening the guilt upon the assassin?"

"That, I maintain, should be left to the police."

"Bah!  The police in this case would be powerless.  The problem is for
us, you and I, to solve, and by the exercise of patience and
watchfulness we shall, I hope, be able to elucidate the mystery.

"The inquiries may carry us far afield; I have a keen presentiment that
they will.  Therefore if I am suddenly absent do not trouble on my
account.  My silence will mean that I am watchful and active.  When I am
abroad I make a point of receiving no letters, therefore do not write.
I always communicate with my friends through the advertisement columns
of the _Times_.  To you I shall be `Silence.'

"Take the paper daily and watch for any message I may send you.  You
have a car outside, I suppose?  I wonder whether you would take me to
Tottenham Court Road?" he asked.

Thereupon we went below, and after a whispered conversation with
Antonio, who was waiting in one of the back rooms, he mounted into the
car, and Dick drove us very slowly through the fog half-way down
Tottenham Court Road, where Kirk alighted.

"Shall I wait for you?"  I asked.

"No," he replied; "I really don't know how long I shall be.  Besides, I
shall not return to Bedford Park to-night.  It's very kind of you, but I
won't trouble you further.  Good night, Mr. Holford!  Perhaps I shall
see you to-morrow.  If not, then recollect to keep an eye upon the
_Times_ for a message from `Silence.'"

And he shook my hand, descended, and went forward into the yellow fog.

My curiosity was aroused; therefore in an instant I had resolved to
follow him and ascertain whither he went.

In the direction he had taken towards Oxford Street, I started off, but
before me the lights blurred in the misty obscurity.  Foot-passengers on
the pavement loomed up in the uncertain light and melted again, and as I
hurried on I discerned the figures before me with difficulty.  Where the
shopfronts were lit were patches of red mist, but where they were closed
it was almost complete darkness, for in that neighbourhood the fog was
thicker than further westward, and Dick had had considerable trouble in
finding his way there at a snail's pace.

In my haste I collided with several persons coming my way, apologising
and going forward again until I came to a corner where a shop was
well-lit.  Of a sudden I distinguished the man I was following; he had
halted in conversation with the shop-keeper, who was pointing up the
side street.

In the fog, Kirk was evidently out of his bearings.

I drew back, so as to escape observation, but I watched him plunge into
the darkness of the side street, and I was soon at his heels.  It was a
squalid neighbourhood into which we had entered.  I had been through it
before, but was not certain which street it might be down which we were
going.

Guided by his footsteps I went on behind him.  Fortunately my tread was
soft, owing to the rubber heels I wore.  At the crossing I listened, at
first uncertain whether he had turned to the right or left, or gone
straight on.

Again the footsteps sounded out of the obscurity, which now caused my
eyes to smart, and I knew that he had gone straight forward, so on I
went.

At the next corner I was nearer him, near enough to distinguish that he
crossed the road and suddenly turned along the pavement to the right.
We were evidently going in the direction of Fitzroy Square, though in
which street I had no idea.  In fear lest his quick ears should detect
that I was following, I fell back a little, allowing him to get further
in front.  The houses we were then passing were good-sized private ones
interspersed with shops, substantial houses of the usual style found in
the decayed districts of London, dark, gloomy, and mysterious-looking.
I recognised that we were in Cleveland Street.  Then we turned again--
the first turning on the left round the corner by a laundry.

Of a sudden I heard Kirk halt, as though in doubt.  It seemed as though
he was retracing his steps, having passed the house of which he was in
search.  Quick as thought, in order to avoid meeting him face to face, I
stepped off the kerb into the roadway.

He passed by within a few yards of me, yet entirely unconscious of my
proximity.  Then he repassed, as though having satisfied himself that he
had not yet reached his goal.  In a London fog, one house is very much
like another, especially in a side street.  In the distance I saw a red
glimmer--the light of a surgery.

Two dark, evil-looking men lurched past me, and then a woman,
half-drunken and reeling.  For a few seconds I lost his footsteps, but
again they reached my ears.  The sound was a different one.  He had
ascended one of the flights of steps!

I hurried forward, but as I did so I heard a door close sharply.  He had
entered one of those dark houses, but which of four or five I was,
unfortunately, utterly at a loss to decide.

The exterior of each I examined carefully, taking note of their number.
In two of them yellow gas-jets were burning over the grimy fanlights,
throwing out a faint light into the pall of the fog, while in one a
light was burning in the front room of the ground floor.

All were let in squalid apartments, for there seemed a general
frowsiness about that undesirable neighbourhood, where the greater part
of the inhabitants were foreigners of the working class.  Each house,
with its railings and deep area, had but little to distinguish it from
its neighbours, all were dirty, neglected, and forbidding in that
darkness and gloom.

I stood in chagrin at having thus lost sight of my mysterious friend,
and could only wait for his exit.  Two of the houses were within the
zone of the weak light thrown by the street-lamp; the other three were
in obscurity.

In one of them--which one I knew not--Kershaw Kirk had kept an
appointment, arranged, perhaps, by that signal which he had made by the
raising and lowering of the blind.

My position was most tantalising, yet I felt that if I remained there on
watch I should most certainly see him come out, and then at least know
the number of the one he had visited.

Midnight rang out from a church clock somewhere, but there had been no
sign of him.

Dick must, I knew, have grown tired of waiting, and, thinking me lost in
the fog, would slowly creep homeward.  The ever-watchful vigil I was
keeping in that terrible atmosphere fagged me.  I became numbed with
cold, and very hungry.

Yet I dare not leave the spot lest Kirk should come forth, so I stood
leaning against the railings in patience, full of wonder and
apprehension.

More than once I feared that the "dealer in secrets" might notice me
from within if he chanced to look out.  Hence from time to time I
changed my position.

My impression was that he had entered with a latch-key, for scarce had
he reached the top of the steps when he was inside, with the door closed
behind him; either that, or else someone was waiting there to admit him.

Another hour had nearly passed, when suddenly I was startled by a loud
scream--a woman's piercing scream--which appeared to come from the first
of the houses which lay in the darkness.

Twice was that cry repeated, and I sped to the house whence it emanated.
The place was in complete darkness.  No light shone from any window of
the gloomy, dismal house.

A third time was the shriek repeated, coming from the room behind the
railing on a level with the door.  As I stood upon the pavement I was
only a few feet from the window.

"Help!  Help!  For God's sake, help!  You brute!  I thought I had
escaped you.  No!  Ah!  Don't!  I beg--I implore you!  Ah!" shrieked a
refined voice, the voice of a young woman.  And then, in despairing
tones that grew fainter with every syllable, I heard the words long
drawn out.  "Ah!  You--you've--killed--me!  Killed me!--just as you
killed my--dear--father!"

I stood listening to that dying appeal, bewildered, utterly staggered.

What could I think?  Place yourself in my position and ask yourself what
you, in those circumstances, would have thought?

CHAPTER SEVEN.

ANOTHER PERSON BECOMES INQUISITIVE.

I was uncertain what to do.  Was it best to ascend the steps, knock
boldly at the door, and inquire the reason of that frantic appeal?  Or
should I remain silent and watch?

If Kirk had caused the Professor's death, then why had he enlisted my
aid?  But was I not a complete novice, in the detection of crime, and
might not all his protestations of friendship be a mere blind, a clever
ruse to cover the truth?

I stood on the pavement, my ears strained to catch any sound within.
But all was silent again.

Those final words of the woman's desperate appeal for help rang in my
ears: "_You've killed me, just as you killed my dear father_!"

The woman who had shrieked could surely have no connection with the
tragedy in Sussex Place, for, alas!  Ethelwynn Greer was dead.  I had,
with my own eyes, seen her stiff and stark.

Then what did it all mean?  Was this an additional phase of the already
inscrutable problem?

I gazed at the window, where no light escaped through the lowered
Venetian blinds.  The very darkness struck me as strange, for either
there were closed shutters upon the blinds, or some heavy curtains had
been drawn carefully across to exclude any ray of light from being seen
without.

In the neighbourhood wherein I was, I recollected there were many
mysterious houses--secret clubs where waiters and foreigners of the
lower class danced, drank, and played faro, and were often raided by the
police.  Those streets bore a very bad reputation.

After all, I was not exactly certain that the house whence emanated the
shrieks was the actual house into which Kirk had entered.  Hence I was
both undecided and bewildered.  For that reason I waited, my eyes glued
upon the dark door and house-front.

Suddenly, above the fanlight, I saw the flickering light of a candle
carried down the hall, and a moment later the door opened.  In fear of
recognition I sprang back into the roadway, where, at that distance, the
fog obscured me.

Someone descended the steps, and, turning to the left, went in the
direction whence I had come.  I followed stealthily for some distance
until I at last made out the figure in the weak light of a street-lamp.

It was not Kirk, only a forbidding-looking old woman in faded bonnet and
shawl--a typical gin-drinking hag of a type one may see in hundreds in
that neighbourhood.  I had followed her down into Cleveland Street,
where she turned to the left, when it suddenly occurred to me that, in
my absence, Kirk might make his exit.  Therefore I rather foolishly
abandoned pursuit, and retraced my steps.

Judge my chagrin, my utter disgust with myself when, on returning, I
failed to recognise from which house the woman had come!  In that
puzzling pall of fog, which grew thicker and more impenetrable every
moment, I hesitated to decide which of three or four houses was the
place whence the woman's cries had emanated.

That hesitation was fatal to my success.  In my excitement I had taken
no notice of the number upon the door, and now I paced backwards and
forwards before the railings of four houses, all almost exactly similar,
all in darkness, all equally dingy and mysterious.  Which of those
houses held Kershaw Kirk I knew not, neither could I decide from which
of the four had come those despairing cries.

I had been a fool, a very great fool, for not going boldly to the door
and demanding an explanation, even though I might have received a rough
handling, alone and unarmed as I was.  So I returned to the street-lamp
and tried to recognise the house from the point where I had stood when
the first cry had fallen upon my ears.  But, alas! again I could not
decide.

My impulse to follow the woman had been my undoing, for I somehow felt a
strong conviction that Kirk had escaped during my absence in Cleveland
Street, for though I waited in that dense and choking blackness beneath
the red lamp of a surgery at the further corner for still another hour,
he came not.

Therefore I was compelled very reluctantly to grope my way back into the
Tottenham Court Road, where at last I found a hansom, and with a man
leading the horse, I fell asleep as we went westward, so fagged and
exhausted was I by that long and unpleasant vigil.

The wife of a motorist like myself is used to her husband's late hours,
therefore I had little difficulty in excusing myself to Mabel, yet when
I retired to bed no sleep came to my eyes.

That woman's shrill, despairing cry rang ever in my ears.  Those words
of hers were so mysterious, so ominous.

"_You've killed me, just as you killed my dear father_!"

Should I go to the police in the morning and make a clean breast of the
whole affair?

At dawn I found the fog had lifted, therefore, after looking in at the
garage, I called upon Kirk, resolved to pretend ignorance of his visit
to the house off the Tottenham Court Road.  But again I was
disappointed, for he had been absent all night.  His sister was ignorant
of his whereabouts, but, as she explained, his movements were ever
erratic.

This caused me to make another visit to the house, which, in the light
of day, I found to be in Foley Street, an even more squalid
neighbourhood than I had believed.

At the corner of Cleveland Street was the laundry, the windows of which
were painted grey so that the passer-by could not peer within.  The
street seemed to be the play-ground of numberless dirty children, while
the houses, all of which were let in tenements, were smoke-grimed and
dismal.

At some of the windows the cheap lace curtains hung limp and yellow, and
at others the windows had been white-washed to prevent people looking
in.  The neighbourhood was one that had sadly decayed, for even the
public-house a little way up the street was closed and to let.

I stood outside the easily recognised surgery in order to take my
bearings, and quickly discovered the three or four houses from one of
which had come that cry in the night.

Yet which house it was, I knew not.  Therefore what could I do?  To
remain there might attract Kirk's attention if he were within.  Hence I
was afraid to loiter, so I passed on into Langham Street, and thus out
into Portland Place.

I had become obsessed by the mystery of it all.  I returned to Chiswick,
and tried to give my mind to the details of my business, but all without
avail.  I saw that Pelham, my manager, was surprised at my apparent
absent-mindedness.  I knew it was incumbent upon me to go to the
police-station, which was only a few hundred yards from me on the
opposite side of the road, and tell the inspector on duty the whole
story.  Yet somehow the affair, with all its mysterious features, had
fascinated me, and Kershaw Kirk most of all.  The information was mine,
and it was for me to solve this remarkable enigma.

Kirk's absence from home, and his failure to communicate with me, showed
that either he mistrusted me, or that he was purposely misleading me for
the attainment of his own ends.

He had sought my friendship and assistance, and yet next day he had
abandoned me in doubt and ignorance.

I managed to get through the day at the garage, and eagerly bought the
evening paper, anxious to see whether the tragedy had become public
property; but as yet it was unknown.  I dined at home, and I suppose my
manner was so preoccupied that Mabel, my wife, asked:

"What's the matter, Harry?  You seem unusually worried?"

"Oh!  I don't know, dear," I replied, trying to laugh.  "I've had a lot
of things to do at the office to-day," I added in excuse; "I've got to
go back this evening."

Mabel pouted, and I knew the reason.  I had promised to run her and her
sister over to Teddington to see some friends with whom we had promised
to spend the evening.

But I was in no mood for visiting friends.  I went along to Kirk's
house, and, finding him still absent, took the train from Hammersmith to
Baker Street, and walked through Clarence Gate to Sussex Place.

It had just struck nine when I halted at the Professor's door, but I
drew back suddenly when I saw a tall, well-dressed, clean-shaven young
man in hard felt hat and overcoat, standing in the doorway.

He had rung, and was evidently awaiting an answer to his summons.

The place was, I noticed, in darkness.  Antonio had evidently omitted to
switch on the light in the hall.

What could that young man want at the house of death?

Unfortunately, I had not been quick enough, for as I halted he turned
upon me, realising that to call there was my intention.

"This is strange!" he remarked to me, "I've been ringing here nearly
half an hour, and can get no reply.  Yet when I passed the front of the
house there was a light in the small drawing-room.  I've never before
known the place to be left; there are always servants here, even if the
Professor and his daughter are absent."

It occurred to me that Antonio had detected him from within, and that he
might be an unwelcome visitor.  I recollected Kirk's strict injunctions
to the faithful Italian.

"Antonio may be out," I suggested.

"But the maids would surely be at home," he argued.  "I wonder if
thieves are inside?  I somehow suspect it," he whispered.

"Why?"

"Because I distinctly heard a movement in the hall about ten minutes
ago," he answered.  "Will you go round to the front and see if there are
lights in any of the rooms, while I remain here?  You'll soon see the
house--the first with the long columns at the drawing-room windows."

I consented, and was quickly round at the front.

But the whole place was in total darkness.  Not a light showed anywhere.

I returned, and suggested that in passing he might have been mistaken.
There were lights in the windows of the adjoining house.

"No," declared the young man, who, by his speech, I recognised was well
educated, "I made no mistake.  There's some mystery here.  I wired from
Paris to Miss Greer this morning, making an appointment this evening.
It's curious that she's out."

"You are a friend of the family, I suppose?"  I asked, eager to know who
the young fellow was.

"Yes," he replied; "and you?"

"I am also," was my answer.  What other reply could I make?  "I believe
the Professor is up in Scotland," I added.

"But where is Antonio and all the other servants?" he argued.

"Well," I said, "their master being absent, they may all be out,
spending the evening; servants have a habit of doing so in the absence
of their masters."

"Then how do you account for the movements I have heard inside?" he
asked.  "No; if the servants are out, then the thieves are within.  Will
you stay here to bar their exit, while I go out and find a constable?"

Mention of the police caused me to wince.  This young man was in
ignorance of what had really occurred.

"I should remain patient a little while if I were you," I said.
"Antonio may return at any moment; he surely cannot have gone far."

"On the contrary, I think he has."

"Why?"

"Well, curiously enough, this afternoon, when I alighted from the Paris
express and was passing through the buffet at Calais, I caught sight of
a man who strangely resembled him.  He turned his head and hurried away.
At the moment I failed to recognise the likeness, and not until half an
hour later, when the boat was already on its way across to Dover, did I
recollect that he was very like the Professor's faithful Antonio."

I held my breath.

CHAPTER EIGHT.

A FRESH TURN IN AFFAIRS.

Here was the whole affair in danger of being exposed to the police and
public by this young man's encounter with the Professor's servant!  If
it were exposed, then I should be compelled to give some account of
myself.  It would certainly be difficult to convince the police that I
had no knowledge of the Professor's death.

"Well," I remarked, "that Antonio should be leaving Calais seems
somewhat curious, but perhaps it may have only been somebody resembling
him."

"Of course, I'm not quite sure," the young man replied; "but is it not
curious that Miss Greer and the servants are all out?  The Professor is
always so very careful of his experiments and the contents of his
laboratory that the house is never left untenanted."

"I've called quite by chance and upon business," I explained.  "I'm a
motor-car engineer, and I live in Chiswick.  My name is Holford."

"Mine's Langton--Leonard Langton," he answered.  Then, after a second's
hesitation, he added, "Ethelwynn--Miss Greer--is to become my wife.
That's why I'm surprised that she hasn't kept the appointment I made."

I was silent.  What if I told him of the girl's mysterious death?  What
would he say?  How would he act?

He seemed a smart, active, well-set-up fellow, quick, energetic, with a
pair of merry grey eyes and a good-natured smile.  Indeed, I took to him
from the first.  Yet how dare I divulge a word of what I knew?

"The only thing is to wait," I suggested.

"But if the Professor is in Scotland, as you say, why have you called
this evening?" he asked, with some little suspicion, I thought.

For the moment I was nonplussed.

"I wondered whether he had returned," was my rather lame reply.  "I
simply called on the off-chance of seeing him."

"Was your business of a pressing nature?" he asked, still wondering, I
think, whether I might not have some connection with thieves who might
be within.  Perhaps he now suspected me of being an accomplice, set to
watch outside.  My hesitation when he suggested calling the police had
no doubt aroused his suspicion.  Besides, I suppose my agitation had
caused him some surprise, for I was in deadly fear lest the police
should be called, and should enter there.

The dead girl's lover was a man of strongly marked character, that I
could see.  When once he learned the truth I should surely be suspected
of having secret knowledge of the crime!

"Well?" he asked, as we still stood before the closed door, "what shall
we do?"

"Wait," I again suggested, "the Professor is evidently still away.  He
may have sent Antonio across to the Continent upon some business."

"If so, then there are undoubtedly thieves within.  Since I've been
waiting here the light in the small drawing-room overlooking the Park
has been extinguished--put out, no doubt, immediately I rang.  No," he
went on, "we must call the police.  Will you go and get a constable--or
shall I?"

"You go," I said, in a blank voice.  "I--I'll wait here."

I saw that the game was up.  His suspicions were aroused, and he
intended to take immediate action.

"There's sure to be a policeman along at Clarence Gate," he said; "I've
often noticed a man on point-duty there.  But," he added, suddenly
facing me and looking straight into my eyes, for the street-lamp shone
brightly upon the spot where we were standing, "tell me, Mr. Holford,
have you told me the actual truth?"

"The truth!"  I echoed.  "Why, of course I have!  Here is my card," and
I gave him one from my cigarette-case, wherein I always carried them.

He read it eagerly, and in exchange gave me one of his, laughing as he
said:

"I feared, perhaps, that you might be in association with the men
inside.  Forgive me for suspecting you, won't you?"

"Of course.  I knew you doubted me," I answered, smiling.  "I'll remain
here until you return, though, to be frank, I don't see very much cause
for alarm."

"I do.  There's a mystery here--one which we must fathom.  Keep watch.
I'll be back in a few moments."

And he left the steps and, turning to the left, disappeared round the
corner.

I stood outside the door, my ears strained to catch the slightest sound.
The young man's presence there was indeed an unfortunate contretemps.

In the silence I could hear my own heart thumping.  Of a sudden,
however, I thought I could detect a sound of movement within.  I
listened attentively.  Yes, I was not mistaken, someone was actually in
the hall!  What if it were the unknown assassin, returned to the scene
of his crime?

My heart-beats quickened.  The dead girl's lover had not been mistaken.
The lights had been put out when the person or persons inside were
disturbed by his ring.  In a few moments he would be there with the
police, and the crime would be properly investigated.  But what account
could I myself give of the reason of my call?  If I were suspected, the
police might inquire into my movements during the past few days and gain
knowledge of my visits there!

My position was growing to one of great seriousness.  Every moment
increased my peril.

Across the narrow road rose the great blank wall of a mews, while in the
room on the first floor above where showed the high, dark window
stretching across nearly the whole frontage of the house, lay huddled, I
knew, the body of the dead Professor.

I was still listening, full of wonder as to who might be lurking in that
house of death, when, of a sudden, I heard the latch touched, and slowly
and silently the big door opened.

I drew back, prepared for a fight, but next second a cry of amazement
escaped my lips when I saw in the darkness of the cautiously-opened door
a man's face--the thin, sallow, frightened face of Kershaw Kirk.

"It's I, Holford!" he gasped.  "I must get away.  Langton must not see
me.  Remember you must not breathe a single word of your knowledge of
myself!  Success now depends entirely upon your silence.  I will wire an
appointment with you to-morrow.  Be careful, or you yourself may now be
suspected."

"But why not tell the police?"  I demanded, barring his way.

"Police be hanged!" he cried impatiently.  "Have I not already told you?
I have no time to argue.  Langton must not see me--he must know nothing
of me.  A word from you would mean loss incalculable, and all hope of
elucidating the mystery would instantly be at an end.  Which way did
young Langton go?"

"Towards Clarence Gate," I replied almost mechanically, for his sudden
appearance there had startled me.

"Good!" he cried; "then I'll go in the opposite direction.  Be silent,
Holford, and rely upon me.  Whatever you may discover, do not betray any
surprise.  In this affair you will probably meet with a good deal that
will surprise you--as it has already surprised me."

"Where's Antonio?"  I demanded.

"Gone."

"Abroad?"

"I--well, how can I tell?  He's left here.  That's all I know," replied
this mysterious man very lamely.

I sniffed in suspicion.

"Do, I beg of you, tell me more of this affair, Mr. Kirk," I urged,
speaking quickly.  "If you are really my friend, if you really wish me
to assist you, why not instruct me how to act?  If you will tell me the
truth, I will keep a still tongue."

"You will be more silent if you remain in ignorance," was his response.
"Listen!  I must get away," and before I could prevent him he had closed
the door quietly behind him.  I noticed that he was attired in clothes
quite different from his usual habit.  Indeed, he was smartly dressed,
wearing a black overcoat with a velvet collar, and well-ironed silk hat.

"Stay and face Langton," I urged.  "Take him into your confidence.
Surely no good can be served by this elusiveness."

"You don't know what you're saying, man!" he cried.  "Let me pass.  I've
been listening to all you told the young man.  Your story was quite a
feasible one.  Keep it up, and affect entire ignorance of me.  It is the
only way if we are to place our hand upon poor Greer's assassin."

"The proper course for me to pursue, Mr. Kirk, is to--"

"Footsteps!  I must go!" he cried hoarsely, in a voice which plainly
betrayed his intense agitation and anxiety not to come face to face with
the dead girl's lover.  "I'll try and see you to-morrow or next day.
Remain in patience till you hear from me.  Good-bye."

And the next instant he ran lightly down the steps and sped away to the
left, out of sight.  All this had happened within three minutes.

Scarce had he disappeared, when Langton, accompanied by two constables,
turned the corner, and found me on guard at the door.  I felt
bewildered.  Kirk's sudden appearance at the door of that house of
mystery had taken me so aback that I had scarcely yet recovered.  Did
not his admission that the faithful Antonio had left bear out Langton's
story of having seen the fellow passing through the buffet at Calais
station?

The young man had, I saw, been explaining his suspicions to the
constables on their way to the house.  I was glad that there was only a
blank wall opposite, otherwise my action in allowing Kirk to leave the
place might easily have been observed and misconstrued.

What, I wondered, was the reason of my strange friend being in there
alone?  Why had the lights been so suddenly extinguished when Langton
had rung the bell?  That he feared Langton was evident.

Why?

Within myself I resolved to put some guarded questions and ascertain, if
possible, what Ethelwynn's lover knew of this man who had so ingeniously
drawn me into that maelstrom of doubt and grim tragedy.

The two constables were instantly on the alert.  They examined the lock
of the front door, conversing in low whispers, then, after a brief
consultation, one of the pair left hurriedly, in order to place a guard
upon the front of the premises, overlooking the garden, which divided
the crescent from the park.

Presently he returned, accompanied by a brown-bearded sergeant, who
recognised Langton as having been witness in a motor-car accident in
Cumberland Terrace a couple of months before.

The sergeant pressed the button of the electric bell for a long time,
and though we waited anxiously there was, of course, no response.

"I'm certain somebody is within," declared Langton excitedly; "I saw the
light quite distinctly."

"Very well, sir, if you're certain," replied the sergeant gruffly,
"we'll have to force an entry.  But remember, if you're mistaken, it
will be a trifle awkward.  The owner might come upon you for damage."

"I'll stand the racket of all that," declared the young man readily.
"There are thieves in here, I'm certain."

"It may be only a maid who has a visitor, and who believes her master,
or young mistress, has returned," I suggested, full of apprehension at
the alarming discovery which must be made as soon as the police entered
and searched the place.

"Then all the worse for her, sir," answered one of the constables
grimly.

And again they banged at the door and continued ringing.  All, however,
was silence and darkness.

What would they have thought had they known that I had allowed the
mysterious Kirk, who had been lurking there, to escape?

Had I acted foolishly in doing so?  I was forced to the conclusion that
I had.

While sergeant and constables were in counsel as to what course should
be adopted, an inspector, who had been warned by the constable on guard
at the front, arrived, and was told Langton's story.

"This is Professor Greer's," he remarked; "I think we'd better force an
entry, sergeant.  That basement window down there looks easy of access,"
and he pointed to a window of the back-kitchen.

"Yes," replied the bearded man addressed, as a constable shone his
lantern down upon it, "we could break the glass and turn back the catch.
There are no bars there."

This course was quickly adopted.  The inspector, taking one of the men's
truncheons, tapped the glass lightly until he had cracked it, and then
pulled the pieces forward till he could insert his hand and release the
catch.

The window thus opened, the two constables, truncheons in hand and
lights turned on, crept into the kitchen and disappeared, while we stood
waiting anxiously without, our ears strained in listening.

A few moments later, one of the men threw open the front door, and
together we entered the dark and silent house of mystery.

I stood back, passing into the wide hall last of all.  There was now no
hiding the grim, astounding truth from police and public.

I held my breath, awaiting the sensation that must be caused by the
discovery.

As I anticipated, a discovery was made very quickly.

But, strangely enough, it was not at all what I had looked for.  It only
added further mystery to the altogether inscrutable problem.

CHAPTER NINE.

I DISCOVER SOMETHING.

On the light being switched on in the dining-room, I held my breath,
expecting that Langton would there find the body of the girl he loved.

It had, however, been removed.

The yellow cushion was still there, flung upon the leather couch where
the unfortunate girl had lain, but there was no sign of any tragedy
having been enacted.

Strangely enough, however, a bright fire burned in the grate, while upon
the table were the remains of a repast--dinner, no doubt--of which three
persons had partaken.  Dessert had been finished, and the three
coffee-cups had been drained, while about the room was a strong odour of
cigars.

Who had been entertained there by Kirk?

The set table did not, of course, strike any of my companions as at all
unusual, and so they passed across to the morning-room on the opposite
side of the hall, one of the constables remaining at the foot of the
stairs in order to prevent the escape of any persons who might be
secreted in the house.

In the dining-room I loitered, for I had noticed in the grate a quantity
of burnt paper.  Therefore, when I was alone, I stooped, and snatched up
a few half-consumed scraps--leaves of a manuscript-book they appeared to
be.  But at the moment, having no time to examine them, I crushed them
into the pocket of my jacket, and followed the quartet on their tour of
investigation.

Every nook and corner, behind chairs, in cupboards, everywhere they
searched, expecting to discover somebody secreted.  But they, of course,
found the house untenanted.

In the smaller drawing-room, where the clean-shaven young man had
noticed the light, there was a fire burning and an odour of cigars,
showing that some man or men had been in the room.  What consultation, I
wondered, had taken place there?

The large drawing-room--the room from whence the Professor had
signalled--was cold and cheerless, while in the study nothing had
apparently been disarranged.

"I think, sir," remarked the inspector to young Langton, "that you must
have been mistaken.  I don't see any evidence of the presence of thieves
here.  The master is away, and the servants are all out for this
evening.  That's all."

"But I'm quite certain there was a light when I first rang," declared
Langton.

"Then if anyone was here, he or she must still be here," replied the
officer with a slightly incredulous smile, while at the same moment I
recollected that as dinner had been served in the dining-room, there
must also have been servants there during that evening.

"Is there no other door--no back door?"  I queried.

"No," replied Langton promptly; "both front and back doors are in Sussex
Place.  The door leading to the park was bricked up by the Professor, as
he was always afraid that undesirable people might enter and steal the
secrets of his experiments.  There are two locked doors leading to the
laboratory, of which he always keeps the keys.  I'll show you them in a
moment."  And he led the way across the landing from the study to the
boudoir.

Here I noticed that the drawers of Miss Greer's little rosewood
escritoire stood open, and that upon the table was a miscellaneous
collection of odds and ends; letters, fancy needlework, and other
things, as though a hasty search had been made among the dead girl's
effects.  To me it appeared that whoever had been making the
investigation had been disturbed in the act and had escaped.

The police noticed it, while Langton exclaimed:

"Look!  Ethelwynn is usually so very tidy!  Somebody has, no doubt, been
turning over her treasures.  For what reason?" and he halted before the
open door leading to the passage to the laboratory.  "Look!"

Inspector, sergeant, and constable all looked, but saw nothing unusual.
The door stood open--that was all.

"Don't you see!" cried the young man excitedly.  "This door--the door
which Professor Greer always keeps fastened--has been burst open.
Somebody has been here!  I was not mistaken after all!"

And he made his way along the passage, opening the second door and
entering the darkness of the great lofty room.  The constable followed
with his lamp, while I held behind, knowing that in a few seconds the
ghastly truth must be discovered.

Langton quickly found the switch, and the place was flooded with light.

At the same moment a strong and pungent smell of some acid greeted our
nostrils, causing us to catch our breath.  It was due, we noticed, to a
bottle of some liquid which had been knocked off the table nearest us,
and lay smashed upon the tiled floor.

Full of fear and trembling, I glanced to the corner in which I had seen
the Professor's huddled-up body; but my heart gave a quick bound of joy.
It was not there!

Already evidences of the double tragedy had been removed.  Was it for
that reason, in order to remove them, that Kershaw Kirk had been there?

"Why!" exclaimed Langton.  "Look! the furnace is alight.  The Professor
certainly cannot be in Scotland!"

I glanced to the left where he had indicated, and saw that the
good-sized brick furnace built in the right-hand wall, in which, by
means of a great electric fan, the Professor could generate, by forced
draught, the intense heat he sometimes required for his experiments, was
aglow.  A fierce fire had evidently been burning there, but it was now
slowly dying out.  The warmth of the laboratory and of the brickwork of
the furnace showed that the draught fan must have been used.

"I wonder what the Professor has been doing to-day?" remarked the
inspector, examining the place with considerable curiosity.

"I wonder rather what intruders have been doing here!" exclaimed
Langton.  "You forget that both doors have been forced."

The inspector stood gazing round the place in silent wonder.

"Well," he exclaimed at last, "I don't see the slightest evidence of
burglars here, sir."

"They may be hidden upstairs," suggested the young man.  "Remember there
are many people very anxious to obtain knowledge of the Professor's
discoveries.  That is why he is always so careful to keep these doors
locked.  His daughter, Ethelwynn, is the only person he ever allows in
here.  He and she even carry in the coal for the furnace, the servants
being excluded."

"But thieves would hardly light up the furnace!" said the officer.

"Unless they wished to destroy something in the fire," responded the
other.

That suggestion held me aghast.  Upon me, like a flash, came the
astounding suspicion that that furnace might have been lit for the
purpose of destroying the evidence of the mysterious crime.  I
remembered Kirk's curious and guarded response when I had referred to
the burial of the body.

Was this, then, the reason why I had found him alone in the house?

I stood staggered by the suggestion.

I was near the furnace--nearer than the others.

Then, when I found speech again, I said:

"If there are intruders in this place, they could not have escaped; they
must certainly be upstairs.  I agree with Mr. Langton that it is
certainly very curious that these doors should have been forced."

"How did you know that the Professor is in Scotland?" he inquired of me
eagerly.

In an instant I had a ready reply.

"Antonio told me so when I called on Monday."

"Did he say when his master would be back?" asked the inspector.

"He said he expected him to return last night, as he had an engagement
to go with his daughter to a ball."

"Then he may have returned and gone to the dance," remarked the officer.
"He may also have lost his keys and been compelled to break open the
doors--quite a likely circumstance.  Three persons dined downstairs
to-night.  He and his daughter and a friend probably dined and
afterwards went out; while the servants, knowing they would not return
before midnight, may have followed them out to spend the evening.  That
at least is my theory at the present."

"That certainly seems to be the most logical conclusion, inspector," I
remarked.

"We must search the upper premises before I accept it," exclaimed
Langton, who, I could see, was still very suspicious that something
unusual had happened.  The meeting with Antonio in the buffet at Calais
had caused him to doubt, and most naturally so.

My eager eyes were fixed upon the glowing furnace, the large, square,
iron door of which was still red-hot, though the heat was now
decreasing.  At the side was a large air-shaft, in which were fitted
electric fans, while on the wall were three switches by which a strong
forced draught could be obtained.

Before the furnace door was a portion of the tiled floor railed off, to
prevent the cinders from being trodden about, and in there I saw a
quantity of ashes.  At the side were several large crucibles, one of
which, still gripped by the iron tongs or holders, contained some metal
which looked like steel.

Carelessly I made a tour of the place, passing the corner where had lain
the Professor's body.  I saw that all traces of blood had been carefully
removed from the tiles.  No one would suspect that any tragedy had
occurred there.

Was this Kirk's work?  Had the man who had such a contempt for the
police--whom he denounced as red-taped blunderers--succeeded in removing
all trace of the crime?

If so, was not that sufficient proof of his own guilt?  Was he not
fooling me when, all the time, he was the actual assassin?

Every fresh fact as presented in that house that night increased rather
than elucidated the mystery.

I longed to take the dead girl's lover into my confidence and tell him,
there and then, all I knew, just as I have told you; but I hesitated.
Had I not given my word of honour to be silent?  And, moreover, like a
confounded fool, I had allowed Kirk to escape!

So now, more than ever, were my lips sealed.  I was bound hand and foot.

In a few moments the four men passed out of the laboratory, while I, as
I had done below, remained behind for a moment.

I stood before the furnace peering into the ashes.

I saw there something which they had overlooked, or, if they had seen
it, could convey nothing to them.

Among those grey ashes lay a black horn overcoat button!

This I snatched up and transferred to my pocket.

Had that bottle of acid been purposely smashed in order to dispel any
unpleasant odour arising from the furnace?

I longed to throw myself upon my knees and examine those ashes, but,
alas!  I dare not.

So I was compelled to follow my companions, rigid and speechless.

CHAPTER TEN.

LEONARD LANGTON MAKES A STATEMENT.

Search of the upper portion of the premises revealed nothing--nothing,
at least, to arouse the undue suspicions of the searchers.

My eager glance was everywhere, but I discerned nothing further of an
unusual nature.  The one great truth had become impressed upon me that
the man Kirk, madman or master criminal, had got rid of the evidences of
his crime.

He must have disposed of the poor girl's body in the same manner as that
of her father!

I recollected that when seated with him in Bath Road, Bedford Park, he
had admitted that he possessed another home.  Was it in Foley Street,
that squalid house where I had heard a woman's frantic screams?

I knew my duty, yet I still hesitated to perform it.  My duty as a good
citizen was to tell the police, openly and frankly, all that I knew.
Yet if I did so, would I be believed?  Now, after I had allowed them to
search the place, I should, if I spoke, surely be suspected of trying to
shield myself.

No, having assumed an attitude of ignorance, I saw I was now compelled
to retain it.  Kirk, clever, crafty, and far-seeing, had most
ingeniously sealed my lips.

Yet why, if he were the actual criminal, had he taken me, a perfect
stranger, into his confidence?  And again, what connection could the
Eckhardt tyre have with the strange affair?

Who were those two mysterious callers who had followed his visit, and
whom Pelham had seen?  What could have been their object?

I stood in the large drawing-room listening to the discussion between
the searchers, who had now returned there disappointed.

"I can only repeat, sir," remarked the inspector, addressing Langton,
"that you must have been mistaken regarding the light in the window of
the next room."

"I'm certain I was not," replied the young man doggedly.  "Someone was
in this house--someone who, when I rang, extinguished the light and
escaped!"

"But how could he have escaped?" queried the officer.

"Ah! that's the mystery.  By the roof, perhaps."

"The trap-door is bolted on the inside," declared the constable; "I
examined it, sir."

"Or by a window leading out on to some leads somewhere?"  I suggested.

"There are no windows unfastened by which anyone could have escaped,"
the sergeant exclaimed; "I've looked at them all."

"Well," exclaimed the young man with a puzzled air, "nothing will ever
convince me that I've brought you all here upon a fool's errand.  I
still maintain that something unusual has happened.  Why has Antonio
fled to France?"

"We must ask the Professor," replied the inspector.  "He may have been
sent by his master upon perfectly legitimate business.  He was entirely
trusted, you say."

"But he saw me in the buffet at Calais, and, turning, hurried away,"
Langton said.  "In other circumstances he would certainly have raised
his hat in greeting; he is a most polite, tactful man."

"Well, sir," laughed the officer, "I don't think we can assist you any
further.  Just go out, 403," he added, turning to the constable, "and
tell the two men in the park that we've finished, and they can go back
to their beats."

"Very well, sir," responded the man, replacing his truncheon as he left
the room.

Both inspector and sergeant soon followed him, leaving Langton and
myself alone.

After the front door had closed, we returned to the big dining-room.

"Well," he exclaimed, "I don't know what your theory is, Mr. Holford,
but I'm absolutely certain that something has happened here.  There is
some crooked circumstance," and I saw deep lines of thought upon his
shrewd, clever, clean-shaven countenance.

Why dare not Kirk meet him?

"The absence of everybody is certainly mysterious," I admitted.

"Doubly mysterious when one takes into consideration the fact that the
doors leading into the laboratory have been forced," he remarked
quickly.  "Three persons dined here to-night.  The Professor entertained
a man-friend.  Who was he?"

"That we can only discover when the servants return," I said.

"Or from the Professor himself," he suggested.

I held my breath.  What would he have said if I had told him the truth--
that the Professor was dead, and that a button from his overcoat had
been lying among the ashes of the furnace?

I glanced around the comfortable room where the fire glowed cheerfully
and the electric lights were so cunningly shaded.  The Professor was,
among other things, a connoisseur of old silver, and upon the sideboard
were a number of fine Georgian pieces, tankards, salvers, candelabra,
salt-cellars, decanter stands, and other things, all of which I
recognised as perfect specimens.

My hand went to my jacket pocket, and I there felt the button.  I
withdrew my fingers in horror.

We had decided to await the return of the Professor.  Await his return!
Surely we would have a long time to wait for his arrival?

I was on my mettle.  I alone knew the truth, and to conceal my secret
knowledge from this shrewd and active young man would, I saw, be
difficult.

We seated ourselves beside the fire, and, having offered me a cigarette
from his case, he began to endeavour to learn more about me.  But at
first I was very wary, and exercised caution in my replies.

He apologised for mistaking me for an accomplice of thieves, whereat I
laughed, saying:

"When we meet the Professor he will perhaps tell you of our long
friendship."

"Curiously enough," he said, looking straight across at me, "I never
recollect Ethelwynn speaking of you."

"I knew very little of the young lady," I hastened to explain; "the
Professor is my friend.  He has, on several occasions, told me what a
great help she was to him in his experiments."

"She is his right hand," declared the young man.  "Her knowledge of
certain branches of chemistry is, perhaps, unequalled in a woman."

"And yet she is delightful and charming, and nothing of a blue-stocking,
I understand," I remarked.

He smiled, for was he not the happy lover!  Ah! what an awakening must
be his ere long!

But we gossiped on.  His face, however, betrayed a great anxiety, and
time after time he expressed wonder why Ethelwynn had not remained at
home to keep the appointment, or left him some message.

Indeed, we searched both her boudoir and her bedroom to find his
telegram, but all in vain.  Then again we returned to the dining-room.

"I suppose you've known the Professor for some years," I remarked,
hoping that he would tell me the story of their acquaintance.

"Oh, yes," answered the young man, twisting a fresh cigarette between
his fingers.  "I first met him and Ethelwynn at the Gandolfi Palace, in
Rome, four years ago.  I was staying with my aunt, the Marchesa
Gandolfi, and they were at the Grand Hotel.  I saw quite a lot of them
all through the Roman season.  The Professor gave some lectures before
one of the Italian learned societies, and I had frequent opportunities
to take Ethelwynn out to see the sights of the Eternal City.  I happen
to know Rome very well, for I spent all my youth there with my aunt, an
Englishwoman, who married into the Roman nobility, and who, like every
other Englishwoman who takes such a step, repented it afterwards."

"You mean she was not very happy with her husband?"  I said.  "I've
heard before that mixed marriages in Italy are never very successful."

"No," he sighed; "my poor aunt, though she became a Marchesa and
possessed a dozen different titles and probably the finest palazzo in
Rome, was very soon disillusioned.  The Marchese was an over-dressed
elegant, who lived mostly at his club, ogled women each afternoon in the
Corso, or played baccarat till dawn.  And Roman society was not at all
kind to her because she was just a plain Englishwoman of a county
family.  Gandolfi was thrown from his horse while riding over one of his
estates down in Calabria two years ago."

"The Professor was a friend of your aunt's, I suppose?"

"Yes, an old friend.  At the time when we met, Ethelwynn had, I found,
an ardent admirer in a young Italian lieutenant of infantry, who had met
her once or twice at the Grand and in the English tea-rooms on the
Corso, and had fallen desperately in love with her.

"The Professor told me of this, and in confidence asked whether I knew
the grey-trousered popinjay.  I did not.  He had apparently told the
Professor of his family and high connections in Bologna, had declared
his love for Ethelwynn, and with her consent had asked the Professor for
her hand in marriage.

"I consulted my aunt, who was much against the matrimonial union of
English and Italians, and in secret I went to Bologna to investigate the
lieutenant's story.  What I found was rather interesting.  Instead of
being the son of a noble but decayed family, he was the only child of an
old man employed as a gardener at a big villa out on the Via Imola, and
so erratic had been his career and so many his amours, that his father
had disowned him.

"I returned to Rome with the father's written statement in black and
white."

"And what happened then?"  I asked, interested.

"The amorous fortune-hunter spent a rather bad quarter of an hour in the
Professor's sitting-room, and was then quickly sent to the right-about.
He quietly got transferred to another regiment up in Cremona, while
Ethelwynn, of course, shed a good many tears."

"And, her disillusionment over, she repaid you for your exertions on her
behalf by becoming engaged to you, eh?"

"Exactly," was his answer as his mouth relaxed into a smile.  "A very
strong attachment exists between the Professor and myself.  I am happy
to believe, indeed, that I am one of his closest friends--at least, that
is what he declared when I asked his permission to marry Ethelwynn.
Perhaps as regards finance I am not all that he might desire," he said
frankly.  "I'm not by any means rich, Mr. Holford.  In fact, I'm simply
a hard-working business man, but I have a very generous and kind
employer in Sir Albert Oppenheim, and my position as his confidential
secretary is one of great trust."

"Sir Albert Oppenheim!"  I echoed.  "Why, he's supposed to be one of the
wealthiest men in England!"

"He probably is," laughed my friend.  "Every rich man, however, has
enemies, and he is no exception.  I've read and heard spoken many very
unkind libels about him; but take it, from one who knows, that no man in
all England performs more charitable work in secret than he."

The name recalled several rumours I had heard, ugly rumours of
dishonourable dealings in the City, where he was one of the greatest,
shrewdest, and most powerful of modern financiers.

I had grown to like Leonard Langton for his frankness.  That he was
devoted to the unfortunate girl was very plain, and naturally he was
anxious and puzzled at her failure to be at home to receive him after an
absence of a month in Portugal, where he had, he told me, been engaged
upon the purchase of the tramways of Lisbon by an English syndicate
formed by Sir Albert.

He lived in chambers in Wimpole Street, with a great chum of his who was
a doctor, and he invited me to look him up, while I began to tell him a
little about myself, my motor business, and my friends.

He was a motor enthusiast, I quickly found; therefore I, on my part,
invited him to come down to Chiswick and go out for a day's run on the
"ninety."

Thus it occurred that, seated in that house of mystery, nay, in that
very room where I had seen his well-beloved lying cold and dead, we
became friends.

Ah! if I had but known one tithe of what that hastily-formed friendship
was to cost me!  But if the future were not hidden, surely there would
be neither interest nor enjoyment in the present.

Suddenly, and without warning, I launched upon him the one question
which had been ever uppermost in my mind during all the time we had sat
together.

"I have met on several occasions," I said, "a great friend of the
Professor's, a man you probably know--Kirk--Kershaw Kirk."

I watched his face as I uttered the words.  But, quite contrary to my
expectations, its expression was perfectly blank.  The name brought no
sign of recognition of the man to his eyes, which met mine unwaveringly.

"Kirk?" he repeated thoughtfully.  "No, I've never met him--at least,
not to my knowledge.  Was he young--or old?"

"Elderly, and evidently he is a very intimate friend of Greer's."

The young man shook his head.  If he was denying any knowledge he
possessed, then he was a most wonderful actor.

Perhaps Kirk himself had lied to me!  Yet I remembered that towards him
Antonio had always been most humble and servile.

I tried to discern any motive Langton could have to disclaim knowledge
of the mysterious Kirk.  But I failed to see any.

As far as I could gather, my companion was not acquainted with the man
whom I had so foolishly allowed to escape from the house.

Yet had not Kirk himself expressed a fear at meeting him?  Had he not
told me plainly that by mere mention of his name to that young man, all
hope of solving the enigma would be at an end?

Perhaps, after all, I had acted very injudiciously in admitting my
knowledge of Kirk.  For aught I knew my remarks might now have aroused
further suspicion in his mind concerning myself.  Yet was not the
temptation to put the question too great to be resisted?

At my suggestion we again ascended the stairs, and re-entered the
forbidden chamber.

I gave as an excuse that I was curious to examine some of the delicate
apparatus which the Professor used in his experiments.  My real reason,
however, was again to examine those ashes before the furnace.

Circumstances, fortunately, favoured me, for almost as soon as we were
inside the laboratory we heard the telephone bell ringing out upon the
landing.

"I wonder who's ringing up?"  Langton exclaimed quickly.  "I'll go and
see," and he hurried away to the study where I had noticed the
instrument stood upon a small side-table near the window.

The moment he had gone I bent swiftly and poked over the dust and ashes
with my hand.

Yes!  Among them were several small pieces of cloth and linen only
half-consumed, some scraps of clothing, together with a silver
collar-stud, blackened by fire.

I feared lest my companion should observe the unusual interest I was
taking in the furnace-refuse, therefore I cleaned my hand quickly with
my handkerchief and followed him.

He had his ear to the telephone, still listening, when I entered the
study.

Then he placed the receiver upon its hook, for the person with whom he
had been conversing had evidently gone.

Turning, with his eyes fixed upon mine, he made in a few clear words an
announcement which fell upon my ears like a thunderbolt.

I believe I fell back as though I had been struck a blow.  By that
plain, simple declaration of his, the dark vista of doubt and mystery
became instantly enlarged a thousand-fold.

I stood staring blankly at the young man, absolutely refusing to believe
my own ears.

What he told me was beyond all credence.

CHAPTER ELEVEN.

THE STORM GATHERS.

"I've just been speaking to Ethelwynn," Langton said.  "She's down at
Broadstairs."

"At Broadstairs!"  I echoed, staring straight at my companion.

"Yes," he replied.  "She tells me that her father went up to Edinburgh,
but was suddenly called abroad upon business connected with one of his
newly-patented chemical processes.  She rang up Antonio, intending to
leave a message for me."

I stood listening to him, utterly dumbfounded.  The young man was being
misled.  Had I not with my own eyes seen the poor girl lying cold and
dead in the room downstairs?  Besides, was it possible that she, who
knew of her father's fate and had seen him lifeless, would tell her
lover that great untruth!

Could this be one of Kirk's ingenious subterfuges in order to gain time?

"Then you are satisfied?"  I managed at last to stammer.

"To a certain degree, yes," he replied, looking at me with a good deal
of surprise, I saw.  "But it does not explain why Antonio is absent
abroad, or--"

"Gone to meet his master most probably," I interrupted.

"Perhaps.  But why has the laboratory been broken open; and, again, why
has the furnace been lit?  Who were the three persons who dined here
this evening?  The Professor is away!"

"Miss Ethelwynn might have entertained two friends before leaving for
Broadstairs," I suggested.

"They were men.  Ethelwynn does not smoke cigarettes."

"Did she say whether she is returning to London?"  I inquired.

"She will let me know on the 'phone tomorrow."

"She didn't tell you her father's whereabouts?"

"She doesn't know.  He's somewhere in Germany, she believes.  He has
been in communication with a strong German syndicate, which it seems has
been formed in Hamburg to work one of his discoveries.  And in his
absence somebody has undoubtedly been prying into his experiments."

"Somebody who you believe was disturbed by your ring at the door, eh?"

"Exactly!" replied the young man, glancing at his watch.  "But now, Mr.
Holford, I think I shall go to my rooms.  I'm tired after my journey.
The Channel crossing was an exceptionally bad one this afternoon.
You'll call and see me very soon, won't you?"

I promised, and together we descended the stairs and left the silent
house.

By his side I walked out by Clarence Gate as far as Baker Street
Station, where we shook hands and parted.

After he had left me I halted on the kerb, utterly bewildered.

It had dawned upon me that there was just a chance of discovering
something further among the ashes of the furnace.  The window, broken by
the police, would afford an easy means of access.  Now, and only now,
was my chance of obtaining knowledge of the actual truth.

Therefore I turned back again, and, loitering before the house, seized
my chance when no one was nigh, opened the basement window and was again
inside.

In a few minutes I was again standing in the laboratory, over which the
glowing furnace threw a red light.  I dared not switch on the
electricity, lest I should give warning to anybody watching outside,
hence I was compelled to grope by the fitful firelight among the ashes.

My examination--a long and careful one--resulted in the discovery of a
metal cuff-link much discoloured by fire, a charred pearl shirt-button,
and a piece of half-burned coloured linen.  As far as I could ascertain
there were no human remains--only traces of burnt clothing.  But charred
bones very much resemble cinders.

Yet were not those remains, in conjunction with the words of Kershaw
Kirk, sufficient evidence of a grim and ghastly occurrence?

I left the house by the window, just as I had entered it, and, walking
as far as the Marylebone Road, entered a small private bar, where, being
alone, I took out the scraps of half-burned paper and eagerly examined
them.  Alas! most of the faint-ruled pages were blank.  The others,
however, were covered with a neat feminine calligraphy, the words, as
far as I could decipher, having reference to certain chemical
experiments of the Professor's!

Those precious notes by Ethelwynn at the Professor's dictation had, it
seemed clear, been wantonly destroyed.

What could have been the motive?  If that were found, it would surely
not be difficult to discover the perpetrator of that most amazing crime.

I returned home more than ever mystified, but carrying in my pocket a
cabinet photograph of the dead man, which I had abstracted from a silver
frame in his daughter's boudoir.  It was theft, I knew, but was not
theft justifiable in such unusual circumstances?

Next morning I was early at the garage in order to carry out a plan upon
which I had decided during the grey hours before the dawn.  In the
telephone book I searched for, and found, the Professor's number at his
seaside cottage at Broadstairs, and asked the exchange for it.

In a quarter of an hour I was informed that I was "through."

"Is Miss Ethelwynn at home?"  I inquired.  "No; she's gone out for a
walk," replied a feminine voice--that of a maid, evidently.  "Who are
you, please?"

"Mr. Kershaw Kirk," I replied, for want of something better to say.

"Oh, Mr. Kirk!" exclaimed the woman.  "Is that you, sir?  Your voice
sounds so different over the 'phone.  Miss Ethelwynn left word that, if
you rang up, I was to tell you that Mr. Langton is back, so you had
better keep out of the way."

"What does Langton know?"  I asked, quickly on the alert.

"Nothing yet; only be very careful.  Are you coming down here?"

"I don't know," I replied.  "I'll ring your mistress up later on to-day.
Is there any other message for me?"

"No, my mistress said nothing else, sir."

"Very well," I said.  "Good morning!" and I rang off.

That conversation created further doubts in my mind.  Here was a girl
whom both Kirk and myself had seen dead, yet she was still alive, and
actually acting in conjunction with him to keep her father's death a
secret!  It was incomprehensible!

What could it mean?

Pelham came to me with some questions concerning the business, but I
only answered mechanically.  I could think of nothing--only of the
mysterious, inscrutable affair in Sussex Place.  The mystery had
possessed my soul.

At eleven o'clock, suppressing all suspicion I held of Kershaw Kirk, I
called at his house; but his sister showed me a telegram she had
received soon after nine o'clock that morning.  It had been handed in at
Charing Cross Station, and was to the effect that he was just leaving
for the Continent.

Another curious circumstance!  He had gone to join that crafty-faced
servant, Antonio Merli.  Now that Leonard Langton had returned, he
evidently thought it wise to make himself scarce.  And yet Langton had
calmly denied all knowledge of him!

A little before five o'clock that afternoon, while sitting in my glass
office in the garage, the man Dick Drake brought me a telegram.  It had
been handed in at the Gare du Nord, in Paris, and was from Kirk.  His
enigmatical words were:

  "Recall all I told you.  I thank you sincerely for helping me over a
  difficulty last night.  Shall rejoin you shortly.  If questioned say
  nothing.  All depends upon you.  Silence!"

I read it through in wonder half a dozen times.

I longed to ring up Ethelwynn Greer again.  It would be a weird
experience to converse with one whom I had seen dead.  Yet I could think
of no excuse.  Kirk had, no doubt, telegraphed to her, for it seemed
that their association was, after all, a very close one.

The day's work ended, I got into a car and drove to the address in
Wimpole Street given me by Leonard Langton.

His chambers were particularly cosy and well-furnished; but his man, a
young foreigner, told me that his master had left for Broadstairs by the
"Granville" from Victoria that afternoon.

Therefore I remounted in the car, and turned away down into Oxford
Street, entirely nonplussed.

I could not discern Kirk's motive in exposing the tragic circumstances
to me.  I did not see in what way I could assist him, even though his
version of the affair were the true one.

Who was this Kershaw Kirk?  That was the main question.  Either he was a
man of extraordinary power and influence, or else a most cunning and
ingenious assassin.  Yet was there no suspicion upon Antonio Merli, the
foreign servant, who seemed hand-in-glove with Kirk?

Recollection of this caused me to turn the car towards the Euston Road
and search along that long, busy thoroughfare for the tobacconist's shop
kept by Antonio's cadaverous-looking brother, Pietro--the only outsider,
apparently, aware of the Professor's death.

For fully half an hour I searched, until, near the Tottenham Court Road
end, I came across a little shop where stationery, newspapers, and
tobacco were displayed in the window.

Entering, I asked the dark-eyed girl behind the small counter if Mr.
Merli kept the establishment.

"Yes, sir, he does," was her reply.

"Can I see him?"

"He's been suddenly called abroad, sir," answered the girl; "he left
London this morning."

"By what train?"

"Nine o'clock from Charing Cross."

"Do you happen to know a Mr. Kershaw Kirk?"

"Yes; he was here last night to see him," replied the girl.  "That's the
only time I've ever met him."

"When do you expect Mr. Merli back?"

"Oh, I don't know, sir!  He's gone to Italy, I expect; and when he goes
there he's generally away for some weeks."

"Then he often goes abroad?"

"Yes, sir; very often.  He has some business, I think, which takes him
away travelling, and he leaves this shop in charge of my married sister
and myself.  He's not married, as I dare say you know."

"He's seldom here, then?"  I remarked, gratified at all this
information.

"He lives out at Acton, and only comes here occasionally."

"You know his brother, of course?"  I asked, after I had purchased some
cigarettes.

"You mean Mr. Antonio?  Oh, yes; he's been here once or twice--for
letters he has addressed here."

"In another name--eh?"  I laughed lightly.

"Yes, they're letters in a lady's hand, so perhaps we'd better not be
too inquisitive," laughed the girl.  And then, after some further
conversation, I told her I would call again in a week's time to
ascertain if she knew her employer's whereabouts, and, re-entering the
car, drove back to Chiswick, my mind clouded by many anxious
apprehensions.

The outlook was every moment growing darker and more perplexing.

CHAPTER TWELVE.

A STRANGE STORY UNFOLDED.

I confess to having been half-inclined, when I returned home that night,
to take Mabel into my confidence.  But I hesitated, because I knew that
her frankness and sense of justice would lead her to suggest that I
should go to New Scotland Yard and lay the whole facts before the
Criminal Investigation Department.

I had no secrets from her--I loved her far too well.  But in this
crooked affair I had most foolishly given my word of honour to say
nothing.

All Kirk's strange declarations and allegations now recurred to me.
Hence I was compelled to abandon all idea of making Mabel my confidante.

I knew, however, by the way she looked at me, that she was troubled and
puzzled by my manner.  Indeed, that evening when I returned and found
her beside the fire in our cosy sitting-room, her slim fingers busy with
some fancy needlework, I recognised by her pointed questions that she
regarded me with considerable apprehension.

Again she asked me what was the matter, and again I replied evasively
that I had just then a good many business worries.  And we dropped the
subject because Gwen, her younger sister, entered the room.

All next day I debated within myself what course I should now adopt,
but, alas!  I could not decide upon any.  The whole affair was such an
entire enigma.  The more I had tried to probe the mystery, the more
utterly inexplicable did it seem.

Reflect for a moment, and you will fully realise the peril of my
position.  To me, it seemed quite plain that I had by my readiness to
accept Kirk's friendship, given myself entirely into the hands of the
conspirators.

If Kirk were truly an honest man and not afraid, he certainly would have
called in the police.  Yet had he not openly admitted his inability to
prove an alibi?

That afternoon, a damp and dismal one, I had to run out on a car to
Tunbridge Wells to see a customer who was purchasing the car which I
drove.  I took Dick with me, and, the car being a "forty-eight," we sped
along pretty swiftly until we halted before the entrance to that
old-world promenade, the Pantiles, near which my customer lived.

Before we got home again it was near midnight, but on that night drive I
resolved that on the morrow I would embark upon the work of amateur
detective, and endeavour to discover something on my own account.

To solve such a complete enigma as that now presented one must, I
realised, begin at the beginning.  And that was what I intended to do.
Therefore, on the following night, at half-past eleven, I left King's
Cross in a sleeping-car for Edinburgh, having first ascertained that the
conductor was the same who had travelled by that train on the night of
the Professor's alleged journey.

He was a tall, lean, fair-whiskered Scot, whose uniform seemed too big
for his shrunken frame, but who bustled up and down the corridor as soon
as the train had started, inquiring of the passengers at what hour they
would like to be called, and whether they would take tea.

I waited until he came to my compartment, and then I put to him certain
questions regarding his passengers on the night of Sunday, the
thirteenth, asking whether he remembered Professor Greer.

"Why, yes, sir," was his answer with a strong northern accent.  "Another
gentleman asked me about the Professor when I got back to King's Cross."

"Did you take the Professor up to Edinburgh?"

"Certainly, sir.  I remember the name.  Indeed, here it is in my book,"
and, turning back a few pages, he showed me the name among those who had
secured sleeping berths in advance.  "As I told the other gentleman who
inquired, he wouldn't have any tea, and told me to call him at Dunbar."

"And when you called him did you then see him in his berth?"

"Yes, sir, he pulled the door back and inquired what kind of a morning
it was."

"Where did he alight?"

"At Waverley, of course.  I handed him out his bags, and one of the
porters of the North British Hotel took them."

"You're quite certain of that?"

"As certain as we're going north to-night, sir," replied the man.

Then I drew forth the Professor's photograph from my pocket and showed
it to him.

"That's the same gentleman, and a very nice gentleman he was, too, sir,"
he declared, the instant his eyes fell upon it.  "But for what reason do
you ask this?  You're the second person who has made inquiries."

"Only--well, only because the Professor is a little eccentric," I
replied diplomatically, "and we are rather anxious to know of his doings
up in Scotland.  Nearly all great men of genius," I added, "are slightly
eccentric, you know."

"Well, he went to the North British," replied the conductor.  "They'll
be certain to recollect him there."

"Do you know the porter who took his bag?"

"Yes, it was Walter Macdonald.  I'll call him when we get to Waverley in
the morning, and you can ask what questions you like."

And the man left me and bustled away, while soon afterwards, as the
great express began to gather speed towards Hatfield, I turned into the
narrow little bed, while we roared along through the dark night.

When I drew aside the blind next morning we were skirting the grey misty
sea, within sight of the Bass Rock.  Therefore I leisurely dressed, and,
punctual to time, stepped out upon the long platform at Edinburgh at
half-past seven.

At a whistle from the conductor, a smartly-uniformed hotel porter
stepped up, and I explained, in a few brief words, the object of my
visit to Edinburgh.

"I remember the gentleman quite well, sir," replied Macdonald, after I
had exhibited the photograph.  "I took his suit-case and kit-bag and
gave them over to the hall-porter.  The gentleman did not engage a room,
I think.  But his first inquiry was for the telegraph-office, and I
directed him to the General Post Office, which is almost next door here.
That's about all I know of his movements."

I gave the man a tip, and, ascending in the hotel lift, passed through
the lounge and entered the big coffee-room which overlooks Princes
Street, where I breakfasted.

Afterwards I lounged about the main hall which opens upon Princes
Street--the entrance from the station being from deep below at the back
of the premises.

I saw that outside the reception office, upon a green baize-covered
board and placed beneath tapes, telegrams for visitors were exhibited,
and the addressees took them themselves.  It would, therefore, be quite
easy for anyone not staying in the hotel to have a telegram addressed
there, and to receive it in secret.  It would also be just as easy for a
person to take anybody else's telegram that happened to be there.

Two young lady clerks were behind the brass grille, and presently I
addressed the elder of the pair, and showed her the photograph.
Neither, however, recognised it.

I turned up the visitors'-book, and saw that on Monday the fourteenth no
person of the name of Greer had registered.

"He was a chance customer, evidently," remarked the elder of the girls
in neat black.  "He arrived, you say, by the morning East Coast express,
therefore he may just have had breakfast and gone on.  Many people do
that, and catch their connections for the North.  In such a case we
never see them.  Both myself and my friend here were on duty all day on
Monday."

"I certainly have never seen the gentleman to my knowledge!" declared
the other.

"But he must, I think, have received two telegrams."

"I remember one telegram, but I do not recollect the other.  We have so
many wires here in the course of the day, you know," the girl replied.
"But what I do recollect is being rung up on the telephone from London
on the following day, with an inquiry whether the gentleman was staying
here."

"You don't know who rang you up?"  I asked.

"I haven't any idea!" she laughed.  "It may have been the police.
They've done so before now."

"Of course he might have stayed here in another name and taken telegrams
addressed to him as Greer," I suggested.

"I scarcely think so," replied the elder of the pair, a tall, smart,
business-like woman.  "If he had, one of us would, no doubt, have
remembered him.  I'd have a chat to the hall-porter at the
station-entrance if I were you," she added.

I therefore sought out the tall, liveried man she had indicated, and
again to him exhibited the portrait.

He remembered the Professor quite distinctly, he told me.  The visitor
deposited in his charge a kit-bag and suit-case, remarking that he was
not quite certain if he would remain the night, and passed on into the
hotel.  "That was about 7:35 in the morning."

"When did you see him again?"

"About noon, when he passed through to the lift, and descended into the
station.  I noticed that he was then wearing a different hat from the
one he had on when he arrived from London," the hall-porter replied.

"When did he take his luggage?"

"About half-past three.  A porter took it below, and it was placed in
the cloak-room."

"You didn't see him again?"

"No, sir.  He probably left by a later train that day."

That was all the information I could gather in that quarter.  The
remainder of the morning I spent idling about Princes Street, that
splendid thoroughfare which has few equals in the world, trying to
decide upon my next course of action.  I had exhausted Edinburgh, it
seemed, and clearly my way lay south again.

Suddenly, on re-entering the hotel to get lunch, a thought occurred to
me, and I sought out the hair-dressing department, making inquiry of the
man in charge, a fair-haired, well-spoken German.

As soon as I showed him the portrait, he exclaimed:

"Ja!  I recollect him--quite well."

"Tell me what you know of his movements," I urged.

I saw that the man regarded me with considerable suspicion.

"I presume, sir," he said, "that you are an agent of police?"

"No, I'm not," I assured him, rather surprised at his remark.  "I'm
simply making inquiry because--well, because my friend is now missing."

"Then I'll tell you what occurred, sir," answered the German, with a
slight accent.  "The gentleman came in about four o'clock and asked me
to shave him.  When I began to put on the soap I realised, however, that
he had himself been cutting off his beard closely.  But I shaved him,
and made no comment.  We hairdressers are used to such things, yet they
sometimes cause us a little wonder."

"Ah!"  I cried.  "Then he left here with his beard shaven clean!  He
intended to disguise himself!"

"No doubt, sir," replied the man, who seemed a particularly intelligent
fellow.  "Because, earlier in the day, while crossing the corridor, I
had noticed him standing near the lift.  He then had a full beard.  I
recollected the clothes he was wearing."

"Did he talk to you?"

"Very little, sir.  He seemed a gloomy, rather silent man."

That was all he could tell me, though he declared that the gentleman had
seemed very agitated and upset while he was being shaved.  His hair was
also cut, and his moustache trimmed.

"Did it alter his appearance much?"  I inquired.  "Very greatly, sir.  I
should scarcely have known him when he left here."

"And you told nobody?"

"It is not my business to pry into customers' affairs," responded the
man, and very justly; "but I took good note of his countenance."

What he told me was certainly remarkable.  The whole of the facts were,
indeed, astounding.

While the unfortunate Professor lay dead in his laboratory in London he
was, at the same time, here, in Edinburgh, making an attempt at
disguise, and sending a reassuring telegram to his daughter!

That Professor Greer had been killed there was not the slightest doubt--
killed, too, behind locked doors, in circumstances which themselves
formed a complete and inscrutable mystery.  Then, if so, who was this
man who had left London with the Professor's luggage, had arrived in
Edinburgh, and whom the hotel-servants and others had identified by his
portrait?

If he were not the Professor, then who could he have been?  One thing
was certain, he could not have been the actual assassin.  Yet if not,
why had he taken such pains to disguise his appearance?

The theory of Greer having a double I put aside at once.  Doubles only
exist in the realms of fiction.  Here, however, I was dealing with hard,
solid facts.

Each phase of the intricate problem became more and more complicated as
I endeavoured to analyse it.  That grey, wintry afternoon I wandered
about the damp streets of Edinburgh, gazing aimlessly in the shop
windows, and afterwards sat for a full hour upon a seat in the deserted
public gardens below the Castle, thinking and wondering until the gloomy
twilight began to creep on, and the lights along Princes Street
commenced to glimmer.

Then, rising, I set off again across the North Bridge, and through High
Street and Johnstone Terrace to the Caledonian Station, and by George
Street and St. Andrew's Street back to the Waverley, a tour of the
centre of the city.  I was merely killing time, for I had decided to
take the night express back to King's Cross.

When I re-entered the hotel it was nearly seven o'clock, and, as I did
so, the porter at the revolving door in Princes Street touched his cap
and informed me that the hairdresser desired to see me again.

I ascended to the first floor, and entered the saloon, where I found the
German with whom before luncheon I had spoken.  He was seated alone,
reading a newspaper.

"Ach, sir!" he exclaimed; "I thought perhaps you had left!  I'm very
glad you are still here!  A most curious circumstance occurred this
afternoon when I went off duty as usual from three till five.  I live in
Forth Street, at the back of the Theatre Royal, and while walking
towards home along Broughton Street, I came face to face with the
gentleman for whom you are searching."

"You've seen him!"  I gasped, half inclined to disbelieve the man's
story, for he was evidently on the look-out for a substantial tip.

"Yes, he recognised me, and tried to avert his face.  But I managed to
get a good look at him, and am absolutely certain that I'm not mistaken.
He was dressed differently, and looks many years younger than when I
first saw him wearing his beard."

"Then he is still in hiding here!"  I gasped quickly.  "Did you follow
him?"

"I did.  I had to exercise considerable caution, for he evidently fears
that he is being traced.  His attitude was essentially that of a man
dreading recognition.  He may be suspicious that you are here, sir."

"But have you discovered where he is living?"  I demanded breathlessly,
my heart leaping.

"Yes, sir," replied the German; "I have."

CHAPTER THIRTEEN.

I LEARN SOMETHING INTERESTING.

Ten minutes later I was with the German hairdresser on a tram-car, going
up Regent Road, towards Abbey Hill.  On turning into the London Road at
the station, we descended, and, crossing the main thoroughfare, entered
one of the narrow, ill-lit turnings on the left, the name of which I was
unable to see.

"I don't know whom to ask for," I remarked to my companion, as we
hurried along together.

"I can only point you out the house where your friend is in hiding,"
replied the man.  "You, of course, know more of his habits than I do."

In a few moments we passed before a tall, drab, dingy-looking house,
which the German pointed out was the false Professor's secret abode.

I longed for the presence of Kershaw Kirk, for I knew not how to act.  I
reflected, however, that the reason of my journey to Edinburgh was to
clear up the mystery, and this thought prompted me to action.

So while he waited in the semi-darkness at the next corner, I returned
to the house and rang the bell.  To the door came a rather dishevelled
girl of about eighteen, evidently the daughter of the occupier.

"You have a gentleman living here," I said.  "Would you kindly tell him
that Mr. Kirk desires to see him?"

"The gentleman's no longer here, sir," replied the girl, in broad
Scotch.

"Gone!"  I ejaculated.

"Yes, sir.  Mr. Martin's who you mean, I suppose, for he's the only
gentleman mother has had.  He packed his things, and left for the
station an hour ago."

My heart fell.  He had evidently realised that the German was following
him, and had escaped us!

"Can I see your mother?"  I asked.  Whereupon I was invited into the
small narrow hall of the musty-smelling house, and a thin-faced, angular
woman in rusty black came forward.

"Pray pardon my troubling you," I said apologetically, "but I have an
urgent message to give to Mr. Martin, who, I understand, has been
staying with you."  It was an advantage that the girl had unwittingly
betrayed the name which the false Professor had adopted.

"Mr. Martin's gone, sir.  He left this evening."

"So your daughter tells me.  But haven't you any idea where he intended
going?"

The woman hesitated, and by that slight pause I felt convinced she knew
something which she intended keeping to herself.

"No, sir, he left quite suddenly," was her hurried reply.  "He had been
out all day, and, returning about five, packed up his things, paid me
what he owed me, together with a week's rent in lieu of notice, and,
getting a cab, drove away."

"To the station--eh?"

"Yes, I heard him tell the man to drive to Princes Street."

"He hadn't been very long with you, had he?"

"About a week.  He came on the Monday, telling me that he had been
recommended by a friend of his, an actor.  I let rooms to
professionals," she added, in explanation.

"He is a very reticent man," I remarked.  "I suppose he seldom went
out?"

"No; he used to read all day, and go for just half-an-hour's stroll at
night.  He struck me as a rather eccentric man."

"So he is," I laughed.  "I'm an old friend of his, so, of course, I
know.  I hope he is not in your debt.  If so, please tell me and I'll
liquidate it."

"Oh, not at all, sir.  He's paid for everything," declared the woman,
upon whom my ready offer to pay her lodger's debts had evidently made an
impression.  "His sudden departure mystified us."

"Did he receive many letters?"

"Only two--and a telegram you sent him--which I found dropped by the
side of his dressing-table."

"From me?"  I echoed, yet next instant recollecting that I had given my
name as Kirk.

"Yes, you telegraphed to him several days ago to meet you at the
Caledonian Hotel in Glasgow.  You are Mr. Kirk, are you not?"

"Ah, of course, I recollect," I laughed.  "Do you think he's gone to
Glasgow?"  I asked, as the sudden thought occurred to me.

"Well, sir," replied the woman, "as you are such an intimate friend of
Mr. Martin's, I think I ought to tell you that, before leaving to-night,
he asked me in confidence to repeat any telegram that might come for him
to the Caledonian in Glasgow, but asking me at the same time to give no
information to anyone who might call and make inquiries as to his
whereabouts."

"Then he's gone to Glasgow to-night!"  I exclaimed, with sudden
enthusiasm.  "If I follow at once, I may find him!"

"I certainly think so, sir," was the woman's response, whereupon I made
a hurried adieu, and, rejoining the German, into whose palm I slipped a
sovereign, was quickly back at the hotel.

I left Princes Street Station at ten minutes to ten that night by the
express due in Glasgow at eleven.  That hour's journey was full of
excitement, for I was now upon the heels of the false Professor, whose
whereabouts and assumed name Kirk knew, and with whom he had made an
appointment.

Was this man, known as Martin, about to meet Kirk?

I laughed within myself when I reflected upon the awkward surprise which
my presence there would give them.  What the lodging-house keeper had
told me proved conclusively that Kershaw Kirk had conspired to cause the
death of poor Greer, and that the story he had told me was untrue.

Yet, again, there arose in my mind the problem why, if he were the
assassin, or an accomplice of the assassin, should he introduce me into
that house of death--myself a comparative stranger!  Alone I sat in the
corner of the railway carriage, thinking it all over, and trying, as I
had so continuously tried, to discern light in the darkness.

I had been a fool--a confounded fool, not to inform the police of my
suspicions at the outset.  The girl Ethelwynn, whom I had seen lying
apparently dead, whose chill flesh I had touched, was alive and well at
Broadstairs!  Was not that, in itself, a staggering mystery, exclusive
of that secret visit of Kirk's to Foley Street, and the woman's cry in
that foggy night?

Was it any wonder, then, that I was neglecting my business, leaving all
to Pelham, with whom I had communicated by telegram several times?  Was
it any wonder that, the circumstances being of so uncanny and intricate
a nature, I hesitated to tell Mabel, my wife, lest I should draw her
into that web of doubt, uncertainty, and grim tragedy?

I had watched the columns of the _Times_ each day to discover the
advertised message promised by Kirk; but there had been none.  I now saw
how I had been as wax in the hands of that clever, smooth-spoken
cosmopolitan.  I believed in men's honesty, a most foolish confidence in
these degenerate days, when morality is sneered at, and honesty is
declared openly to be "the worst policy."

Alas! in this dear old England of ours truth and justice are to-day
rapidly disappearing.  Now that Mammon rules, that divorce is a means of
notoriety, and that charity begins abroad with Mansion House funds for
undeserving foreigners, while our starving unemployed clamour in their
thousands for bread, the old order of things has, alas! changed.

The honest man--though, be it said, there are still honest, sterling men
in business and out of it--goes to the wall and is dubbed a fool; while
the master-thief, the smug swindler, the sweater, and the promoter of
bogus companies may pay his money and obtain his baronetcy, or his seat
in the House of Lords, and thus hall-mark himself with respectability.

While money talks, morality is an absent factor in life, and truth is
but a travesty.  Glance only at the list of subscribers to a Mansion
House Fund, the very basis of which is the desire of the Lord Mayor who
may happen to be in office to get his baronetcy, while its supporters
are in the main part self-advertisers, or donations are given in order
to establish an unstable confidence and extend a false credit.  Thus,
even in our charities, we have become humbugs, because the worship of
the Golden Calf has bred cant, hypocrisy, and blatant self-confidence,
which must ere long be the cause of our beloved country's downfall
beneath the iron-heel of far-seeing, business-like Germany.

Such reflections as these ran through my mind as that night I sat in the
train watching the lights as we neared the great industrial centre on
the Clyde.  I was trying to peer into the future, but I only saw before
me a misty horizon of unutterable despair.

I longed to meet Ethelwynn Greer, and put to her certain questions.  Was
it not a complete enigma, startling and inscrutable, that she, having
seen her beloved father lying lifeless, should utter no word--even to
young Langton, to whom she was evidently devoted?  That fact was utterly
incomprehensible.

At last the train slowed and drew into the great echoing station.  On
alighting I gave my bag to a porter and entered the big Caledonian Hotel
adjoining.  I had stayed there on previous occasions, and knew its huge
dining-room, its long corridors, and its wide ramifications.

I registered in the name of Lamb, deeming it best to conceal my
presence, and while writing in the book, scanned the page for Martin's
name.  It was not, however, there.  I turned back to earlier arrivals
that day, but with no better result.  So I ascended in the lift to my
room on the second floor.

Of course, it was quite within the bounds of possibility that the false
Professor might use yet another name if he wished to avoid being
followed from Edinburgh.  Besides, I had noticed that just as at the
North British at Edinburgh, so here, telegrams were exhibited upon a
board, and could be taken.  Therefore, if a wire came in the name of
Martin, he could quite easily claim it.

After a wash I wandered about the hotel, through the lounge,
smoking-room, and the other of the public apartments.  Yet how could I
recognise a man who was disguised, and whom I had never seen?

I was placed at a disadvantage from the very first by never having met
this man who had posed as the dead Professor.  Yet with the knowledge
that Kirk desired particularly to see him, I felt that there was a
probability of their meeting, and that, if only I remained wary and
watchful, I should come across, amid the hundreds of persons staying
there, the mysterious dweller in Bedford Park.

From my arrival at eleven till half-past one I remained on the alert,
but saw no one I knew.  Therefore I retired to bed, thoroughly worn-out
by that constant vigil.  Yet I was in no way disheartened.  The false
Professor had started from Edinburgh for that destination, and was, I
felt confident, staying there under another name.  It only lay with me
to unmask him, or to wait until the pair met clandestinely, and then to
demand to know the truth.

Surely in all the annals of crime there had never been one so surrounded
by complex circumstances as the tragedy of Sussex Place, and assuredly,
too, no innocent man had been more ingeniously misled than my
unfortunate self.

Next day, from eight o'clock in the morning till late at night, I idled
about the big hotel, ever anxious and ever watchful.  I kept an eye upon
each arrival and each departure.

Then I became slowly and against my will, convinced that the false
Professor had not come to that hotel, but had put up somewhere else,
well knowing that he could obtain the telegraphic message from Kirk
whenever he cared to step in and take it from the board.

Again, even though at the heels of the conspirators, was I yet being
outwitted--a fact which became the more impressed upon me on the third
day of my futile expectancy.

Hourly I watched that telegraph-board, intending to annex quietly any
message addressed to Martin, and act upon any appointment it contained.

But, alas! my watchfulness remained unrewarded.

Twice there had arrived men slightly resembling the dead Professor,
clean-shaven and active, but by careful observation I discovered that
one was a commercial traveller whose samples had been left below in the
station, and the other was a well-known iron merchant of Walsall.

The false Professor, the man who was plainly in association with the
mysterious Kirk, was clearly in Glasgow, yet how was it possible for me
to do more than I was doing towards his unmasking?

Put to yourself that problem, you, my friend, for whom I have chronicled
this plain, unvarnished story of what actually occurred to me in the
year of grace 1907, and inquire of yourself its solution.

"Who killed Professor Greer?"

CHAPTER FOURTEEN.

A REMARKABLE TRUTH.

The morning was cold, with fine driving rain, when at eight o'clock I
alighted from a hansom before my own house in Bath Road, and entered
with my latch-key.  In the dining-room I found Annie, the housemaid, in
the act of lighting the fire, but turning suddenly upon me with
surprise, she exclaimed:

"Oh, sir!  You gave me quite a turn!  We didn't expect to see you back
again just yet."

"Why not?"  I inquired, with some surprise.  "We thought you were with
the mistress, sir."

"With my wife.  What do you mean?"

"Mrs. Holford obeyed your telegram, sir, and has left for Italy."

"For Italy!"  I gasped.  "Where's Miss Gwen?  Go and ask her if she can
see me at once."  And I followed the maid upstairs.

In a few moments Gwen Raeburn, my wife's sister, a young, pretty, dark
girl of seventeen, who wore a big black bow in her hair, came out of her
room wrapped in a blue kimono.

"Why, Harry!" she cried.  "What's the matter?  I thought Mabel had gone
to join you."

"I've just come down from Glasgow, where I've been on business," I
explained.  "Where is Mabel?"

"I don't know, except that I saw her off from Victoria at eleven the day
before yesterday."

"But why has she gone?"

"To meet you," replied the girl.  "The morning before last, at a few
minutes past eight, she received a telegram signed by you, urging her to
meet you at the Hotel Grande Bretagne in Florence at the earliest
possible moment.  Therefore she obeyed it at once, and left by the
eleven o'clock train.  It was a terrible rush to get her off, I can tell
you.  But haven't you been in Florence?"

"No, I've been in Scotland," I repeated.  "Did you read the telegram she
received?"

"Yes; it was very brief, but to the point.  Mabel was annoyed that you
had not told her the reason you had gone abroad without explanation.
She feared that, in view of your preoccupied manner of late, something
disastrous had happened to you.  That's why she left so hurriedly.  I
wanted to go with her, but she wouldn't allow me."

"I wish you had gone, Gwen," I said.  "There's some plot here--some deep
and treacherous conspiracy."

"Why, what has happened?"

"A lot has happened," I said.  "You shall know it all later on.  At
present I haven't time to explain.  I suppose the telegram isn't left
about anywhere?"

"Mabel took it with her."

"You didn't notice whence it had been despatched?"  I asked.

"From Turin.  We concluded that you had halted there, on your way from
Paris."

I was silent.  What plot had those blackguards formed against me and
mine!  Why had my dear wife Mabel been decoyed out to Italy by them?  I
grew apprehensive and furious.

My sister-in-law descended with me to the dining-room.  She saw my
agitation, and after the first surprise had worn off tried to calm me.

"There's a perfectly feasible explanation, I'm sure, Harry," she said.
"Perhaps it is some practical joke being played upon you and Mabel by
your friends.  They want you out in the South for a week or two to
escape from the cold and wet of the London spring.  I wouldn't worry, if
I were you."

"Ah, Gwen!"  I sighed.  "You are unaware of all the grim circumstances,"
I said.  "There's a serious conspiracy here, I'm convinced.  The hand of
a secret enemy has been lifted against me."

Had that crafty servant at Sussex Place dispatched the false message, I
wondered?  Or was it Kirk himself?  And if so, with what motive?  Was
Mabel, my beloved and devoted wife, to fall helplessly into their
unscrupulous hands?  My blood rose within me when I reflected how
innocently I had walked into the trap which my mysterious neighbour had
prepared for me.

I took up a Bradshaw, and saw that if I left Charing Cross by the boat
train at 2:20 I might, by good chance, catch the night mail for Italy by
the Mont Cenis from the Gare de Lyon.  I could only do it if we ran into
the Gare du Nord in time.  But from experience I knew that the afternoon
service to Paris was pretty punctual, and one usually arrived in the
French capital about 9:20.  Then, by the aid of a taxi-cab, I could get
across to the Lyons station in time.

So I decided to make the attempt.  I had been in Italy several times
when a youth, and knew Italian fairly well.  My father, before the smash
in his fortunes, had rented a villa for several years up at Vallombrosa,
in the chestnut-clad mountains above Florence.

"May I come with you, Harry?" pleaded my sister-in-law.  "If Mabel is in
any danger it is only right that you should take me to her."

I knew how devoted the girl was to her sister.  A year ago she had come
to us from Caen, where she had been at school, and among the languages
in which she was proficient was Italian.  I hardly cared, in the
circumstances, to leave her alone; therefore, although a big hole must
be made in my slender bank account, I resolved to take a second ticket
for her.

When I announced my decision her dark eyes sparkled with delight, and
she clapped her hands.

"You are a real good brother, Harry!" she cried.  "I don't want any
breakfast.  I'll go and begin to pack at once.  I've never been in
Italy, you know."

I told her that in the circumstances of the rush we must make across
Paris I could only allow her hand-luggage, and she sped away upstairs to
put on her frock and to commence placing her necessaries together.

Afterwards, greatly agitated and full of dark apprehension, I got on, by
telephone, to the Wagon-Lit office in Pall Mall, and reserved berths for
us both on the Rome express from Paris as far as Pisa, where I knew we
would be compelled to change.  Then I addressed a long telegram to Mabel
at the Hotel Grande Bretagne, on the Lung' Arno, at Florence, explaining
that she was the victim of a bogus message, but that we were rejoining
her at once, in order to bring her home.

I judged that she must already have arrived in Florence, but
unfortunately there would be no time to receive a reply ere we left
London.

Having despatched the message, I went round to the garage, and, telling
Pelham of my sudden call abroad, gave him certain instructions, drew a
cheque for wages, and otherwise left things in order.

Then I called upon Miss Kirk, but she denied all knowledge of her
brother's whereabouts.  The _Times_, which I had just bought in the High
Road, Chiswick, contained no advertised message from him.  Nor did I
expect any.

My intention now was one of bitter retaliation.  I had been befooled by
the man who I had proved held secret knowledge of the mode of the poor
Professor's tragic end.  By this message to my wife someone had touched
my honour, and I intended that he should dearly pay for it.

Gwen, girl-like, was all excitement at the prospect of this flying
journey to the south.  At one moment she endeavoured to reassure me that
nothing was wrong, while at the next she expressed wonder at the motive
of the mysterious message.

At last, however, we found ourselves seated in the corners of a
first-class carriage, slowly crossing the Thames on the first stage of
our dash to Italy.  The outlook was grey and cheerless, precursory,
indeed, of a dismal conclusion to our journey to the far-off land of
sunshine.  We got out at Folkestone Harbour, however, well to time, and
that evening were fortunately only seven minutes late in arriving at the
Gare du Nord.  We had dined in the train, so, therefore, entering a
taxi-cab, we were soon whirled across Paris to the Gare de Lyon, where
we had only eight minutes to spare before the departure of the _rapide_
for Rome.

All that night, as I lay alone in my sleeping-berth while the great
express rocked and rolled on its way to the Alpine frontier, my mind was
full of gravest apprehensions.  Gwen had been given a berth with another
lady at the further end of the car, and I had already seen that she was
comfortable for the night.  Then I had turned in to spend those long
dreary hours in wakeful fear.

I could discern no motive for inveigling my wife--with whom Kirk had
never spoken--to a destination abroad.  Yet one curious point was quite
plain.  That mysterious dweller in Bath Road--the man with the pet
parrot--was well aware of my absence in the north.  Otherwise he would
not have forged my name to a message sent from Turin.

For what reason could he desire Mabel's presence in Florence?  He must
have some object in her absence.  Perhaps he foresaw that her absence
meant also my absence--and that my enforced journey meant a relaxation
of the vigil I had established upon the man who had gone north on the
night of the Professor's assassination.  That was the only feasible
theory I could form, and I accepted it for want of any better.  But in
what a whirlwind of doubt and fear, of dark apprehensions and breathless
anxiety I now existed you may well imagine.

Gwen, looking fresh and bright and smart in her blue serge gown, came to
me next morning, and we had our coffee together at a wayside station.
Though we sat together through the morning hours until we stopped at the
frontier at Modane, she refrained from referring to the reason of
Mabel's call abroad.  The young girl was devoted to her sister, yet she
did not wish to pain or cause me any more anxiety than was necessary.

After passing through the great tunnel, emerging on the Italian side and
coming to Turin, where we waited an hour, the journey became uneventful
through the afternoon and evening until the great bare station of Pisa
was reached, shortly before midnight.

Here we exchanged into a very cold and very slow train which, winding
its way in the moonlight through the beautiful Arno valley all the
night, halted at the Florence terminus early in the glorious Italian
morning.

"_Fi-renze!  Fi-renze_!" cried the sleepy porters; and we alighted with
only about half a dozen other passengers who had travelled by that
_treno lumaca_--or snail-train, as the Tuscans justly call it.

Then, taking one of those little open cabs so beloved by the
Florentines, we drove at once to the well-known hotel which faces the
Arno, close to the Ponte Vecchio.

Florence, in the silence of early morning, looked delightful, her old
churches and ponderous palaces standing out sharply against the clear,
blue sky, while, as we passed a side street we caught sight, at the end
of the vista, of the wonderful black-and-white facade of the Duomo, of
Giotto's Campanile, and Brunelleschi's wondrous red-tiled dome.

A few moments later we stepped from the cab and entered the wide,
marble-floored hall of the hotel.

"You have a Mrs. Holford staying here?"  I asked in English of the
manager, who was already in his bureau.

"Hol-ford," he repeated, consulting the big frame of names and numbers
before him.  "Ah, yes, sir; I remember!  But--" He hesitated, and then
inquired, "Will you pardon me if I ask who you may be?"

"I'm Henry Holford, madame's husband," I replied promptly.

And then the man told us something which caused us to stare at each
other in speechless amazement.

The man was a liar--and I told him so openly to his face.

His astounding words rendered the remarkable enigma more complex than
ever!

CHAPTER FIFTEEN.

A MAN DECEIVES A WOMAN.

The story told me by the bald-headed Italian hotel-keeper was that
another man had usurped my place!

He said that Mrs. Holford, accompanied by her husband, had arrived at
about seven o'clock on the morning of the day before yesterday, remained
there the day, and had left by the express for Rome at five o'clock that
same evening.

"You don't believe it, sir!" the man exclaimed with some warmth.  "Well,
here is the gentleman's signature!"  And he showed me upon a printed
slip, whereon hotel visitors in Italy write their names according to the
police regulations, boldly inscribed in a firm hand, "Mr. and Mrs. Henry
Holford.  Profession, automobile engineer.  Domicile, London.  British
subject."

I stared at the words utterly confounded.  Somebody had assumed my
identity!  Yet how was that possible with Mabel present?

"What kind of man was madame's husband?"  I inquired, while my
sister-in-law stood by astounded.

"He was slightly older than yourself, sir, with a moustache turning
grey."

Surely it could not be that arch-scoundrel Kershaw Kirk!

"Was he about fifty, and rather thin?"

"Yes," replied the _hotelier_.  "He spoke Italian very well; indeed,
with scarcely any accent."

My suspicion at once fell upon Kirk.  Yet how could he so impose upon
Mabel as to be allowed to pass as her husband?  She had never before
spoken to the fellow, and had, I knew, held him in instinctive dislike.

"They were out all yesterday morning driving up to Fiesole," he added.

"You don't happen to know to which hotel they've gone in Rome?"  I
asked.

"No.  There is a telegram here for madame.  It arrived half an hour
after their departure.  They would leave no word with the hall-porter
regarding the forwarding of letters."

"I am her husband," I said, "and that telegram is evidently mine, which
has been delayed in transmission, as messages so often are in this
country.  As her husband, I have a right to open it, I suppose."

"I regret, sir, that I cannot allow that," said the man.  "You have
given me no proof that you are madame's husband."

"But I am!"  I cried.  "This lady here is my wife's sister, and will
tell you."

"Yes," declared the girl, "this is Harry, my brother-in-law.  The other
man, whoever he may be, is an impostor."

The short, bald-headed Italian in his long frock-coat, grew puzzled.  He
was faced by a problem.  Therefore, after some further declarations on
my part, he handed me the message, and I found, as I had expected, it
was my own, which, unfortunately, had never reached her to reassure her.

Of course, I was not certain that Mabel's companion was actually Kirk.
Indeed, as I reflected, I grew to doubt whether she would accept any
word he told her as the truth.  Yet whatever the story related about
myself to her it must be a strange and dramatic one, that it should
induce her to travel across Europe in company with a stranger.

I had never had the slightest reason to doubt Mabel's fidelity.  She had
always been a good, honest and true wife to me, and our strong affection
was mutual.  Indeed, few men and women led more blissful, even lives
than we had done.  Thoroughly understanding each other's temperaments,
we were content in each other's affection.

No, even though this man might tell me this astounding story, I refused
to give it credence.  The grey-moustached stranger, whoever he might be,
was a scoundrel bent upon entrapping my wife, and had done so by
relating some fictitious story about myself.

This theory I expounded to her young sister Gwen as we sat at our coffee
half an hour later.  We had resolved to rest until eleven, when an
express left for Rome.  I intended to follow her and rescue her from the
hands of those who were most certainly conspirators.

More mystified than ever, we therefore travelled south to the Eternal
City, arriving there in the early hours of the next morning, and going
to the Grand Hotel, which was full to overflowing, the Roman season
having already commenced.

To find my beloved wife was now my sole aim.  I thought naught of the
startling mystery of Sussex Place, or of the strange identity of the
false Professor.  I had abandoned the inquiry in order to recover from
peril the woman I loved so dearly.

The young girl, my companion, was; beside herself with fear, dreading
what had occurred; while I myself became more and more puzzled as to the
motive for inveigling Mabel abroad.  She had not the slightest
connection with the secret tragedy; she was, indeed, in ignorance of it
all.  For what reason, therefore, was she being misled, and why, oh,
why, did she allow this perfect stranger to pose as myself?

I hardly slept at all that night, having searched all the published
visitors' lists in vain, and as early as seven o'clock next morning I
started upon a tour of the hotels to make personal inquiry.  At the
Russia, the Modern, the Continental, the Milan, and other well-known
houses of that class I conned the names of the visitors for my own, but
though I was occupied the whole day upon the task, snatching a hasty
luncheon at a little _trattoria_ I knew just behind the Ministry of
Posts and Telegraphs, all was, alas! in vain.

Part of the time Mabel's sister was with me, until she grew tired, and
returned alone to the hotel in a cab.

Earlier in the day I had telegraphed to Pelham to inquire whether Mabel
had sent me any message at home, but the reply came that neither
telegram nor letter had been received.

Though there seemed no connection whatever between the tragedy in Sussex
Place and my wife's flight, yet I could not help suspecting that there
was, and that my apparent abandonment was due to the subtle, satanic
influence of my mysterious neighbour.  I was now all the more anxious to
condemn him to the police.  The remains of the poor Professor had been
cremated in his own furnace, and by the blackguardly hands of the
assassin.

Yet, before I could raise the finger of denunciation, I had to discover
the fellow's whereabouts, and this seemed a task impossible to
accomplish.  I had kept my eye upon the _Times_ daily in the course of
my quick journeys during that most eventful week, but no advertisement
had appeared.

Next day, and the next, I spent alternately searching the hotels and
idling in the Corso, on the Pincian, among the tourists in the Forum, or
in the broad Piazza Colonna, the hub of Roman life.  Among the hosts of
foreigners who walked and drove in the Corso at the hour of the
_passeggiata_, my eyes, and those of my bright little companion, were
ever eager to find my dear wife's handsome face.

But we saw her not.  She and the man posing as myself had entirely and
completely disappeared.

I sought counsel of the Questore, or chief of police, who, on hearing
that I was in search of my wife, ordered the register of foreigners in
Rome to be searched.  But two days later he informed me with regret that
the name of Holford did not appear.

In face of that my only conclusion was that, after leaving Florence,
they had suddenly changed the course of their flight.

Their flight!  Why had Mabel fled from me, after speeding so swiftly to
meet me?  Ay, that was the crucial question.

Late one afternoon I was standing upon the Pincian, leaning upon the
balustrade of that popular promenade of the Romans, and watching the
crowd of winter idlers who, in carriage and afoot, were taking the
fresh, bright air.  I had been there every day, hoping against hope
either to recognise Mabel or the man Kirk among the crowd of wealthy
cosmopolitans who thronged the hillside.

Before me moved the slow procession of all sorts and conditions of
carriages, from the gaudily-coloured, smart motor-car of the young
Italian elegant to the funereal carozza of the seedy marchesa, or the
humble vettura of the tweed-skirted "Cookite."  Behind showed the soft
grey rose of the glorious afterglow with the red roofs, tall towers and
domes of the Eternal City lying deep below.  Against the sky stood the
tall cypresses--high, gloomy, sombre--and over all spread that light
film of mist that rises from old Tiber when the dusk is gathering.

The scene was, perhaps, one of the most picturesque in all Italy, even
surpassing that from the Piazza Michelangelo in Firenze, but to me,
hipped and bewildered as I was, the chatter in a dozen tongues about me
was irritating; and I turned my back upon the crowd, leaning my elbows
upon the stone parapet, and gazing over the gay, light-hearted capital
whence at that moment came up the jangling of bells started by the great
bell at St. Peter's and echoing from every church tower, the solemn call
to evening prayer that is, alas! ever unheeded.  In modern Italy only
the peasant is pious; in the _alto mondo_ religion is unfashionable.

Perhaps you have driven in the Corso, that narrow and most disappointing
of thoroughfares, gossiped in the English tea-shop at five o'clock,
taken your vermouth and bitters in the Aregno, and climbed the Pincian
to see the sunset.  If you have, then you know that life, you recognise
amid that crowd faces of both sexes that you have seen at Aix, at Vichy,
at Carlsbad, at Ostend, or in the rooms at Monte Carlo, many of them
vicious, sin-hardened faces, careless, indolent, blase; few, alas! with
the freshness of youth or the open look indicated by pure-mindedness.

On the Pincian you have the light-hearted thoughtless world which exists
only to be amused, the world which laughs at grim poverty because it
obtains its wherewithal from the labours of those poor, underpaid and
sweated millions in other countries who must work in order that these
few favoured ones may indulge in their extravagances.

Sick to death, disappointed, worn out by a continual vigilance and with
a deep anxiety gnawing ever at my heart-strings, I had turned from the
scene, and was gazing across into the rose-tinted mists, when of a
sudden I heard a voice at my elbow, exclaiming in broken English:

"Why, surely it's the Signor Holford!"

I turned quickly, and to my amazement found myself confronted by the
thin, sinister face of the dead Professor's servant, Antonio Merli.

CHAPTER SIXTEEN.

ANTONIO SPEAKS PLAINLY.

"You, Antonio!"  I gasped, staring at the fellow who, dressed in a dark
grey suit and soft black felt hat, presented an appearance of
ultra-respectability.

"Yes, signore, I am very surprised to find you here--in Rome," he
replied.

"Come," I said abruptly, "tell me what has occurred.  Why did you leave
London so hurriedly?"

"I had some family affairs to attend to," he answered.  "I had to go to
my home at Lucca to arrange for the future of my two nephews whose
father is just dead.  Pietro joined me there."

"And you were joined also by Mr. Kirk?"  I said.

"Ah, no, signore!" protested the thin-faced Italian with an emphatic
gesture.  "I have not seen him since I left London."

"Are you quite certain of that, Antonio?"  I asked slowly, in disbelief,
as I looked straight into his face.

"Quite.  I know that he came abroad, but have no idea of his present
whereabouts."

"Now tell me, Antonio," I urged, "who and what is Mr. Kirk?"

The Italian shrugged his shoulders, answering:

"Ah, signore, you had better not ask.  He is a mystery to me--as to you,
and as he was to my poor master."

"He killed your master--eh?"  I suggested.  "Now tell me the truth--once
and for all."

"I do not know," was his quick reply, with a strange flash in his dark
eyes.  "If he did, then I have no knowledge of it.  I slept on the top
floor, and heard nothing."

"Who was the man who went to Edinburgh on the night of the tragedy?"

"Ah!  _Dio mio_!  Do not reopen all that puzzle!" he protested.  "I am
just as mystified as you yourself, signore."

I looked straight in the man's face, wondering if he were speaking the
truth.  His hard, deep-lined countenance was difficult to read.  The
Italian is such a born diplomatist that his face seldom betrays his
thoughts.  He can smile upon you sweetly, even though behind his back he
grips a dagger ready to strike you to the heart.  And so old Antonio's
face was sphinx-like, as all his race.

"You saw Leonard Langton at Calais," I remarked.

"He told you that!" gasped the dead man's servant, with a start.  "What
did he say of me?"

"Nothing, except what was good.  He told me that you were a trusted
servant of the Professor."

"Ah, my poor, dear master!" echoed the man, his face turned thoughtfully
away towards the afterglow.  "If I knew--ah, _Madonna mia_, if I only
knew the truth!"

"You suspect Kirk?"  I suggested.  "Why not tell me more?"

"I suspect him no more than I suspect others," was his calm reply.  "Be
certain, signore, that there is much more behind that terrible affair
than you suspect.  There was some strong motive for my poor master's
death, depend upon it!  But," he asked, "where did you meet the Signor
Langton?"

Briefly I related the circumstances of Kirk's presence in the house, his
escape, and the discovery I afterwards made in the laboratory.

"You actually found the evidences of the crime had been destroyed!"
cried the man.  Yet my sharp vigilance detected that beneath his
surprise he breathed more freely when I announced the fact that the body
of the Professor was no longer existent.

"Yes," I said, after a slight pause, during which my eyes were fixed
upon his.  "Destroyed--and by Kershaw Kirk, whom I found alone there,
with the furnace burning."

The Italian shook his head blankly.  Whether he held suspicion of Kirk
or not I was unable to determine.  They had been friends.  That I well
knew.  But to me it appeared as though they had met in secret after the
tragedy, and had quarrelled.

I told the man nothing of my journey to Scotland or of the puzzling
discoveries I had made; but in reply to his repeated questioning as to
why I was in Rome I explained that I was in search of my wife, telling
him of the unaccountable manner in which she had been called away from
London by means of the forged telegram.

"And you say that the signora knew nothing of the affair at Sussex
Place?"

"Nothing, Antonio.  It was not a matter to mention to a woman."

"You suspect Kirk, of course, because his description is very like the
man described as being with her in Florence.  What motive could he have
in enticing her away from you?"

"A sinister one, without a doubt," I said.

"But, Antonio, I beg of you to tell me more concerning that man Kirk.
You have known him for a long time--eh?"

"Four years, perhaps.  He was a frequent visitor at the Professor's, but
young Langton hated him.  I once overheard Miss Ethelwynn's lover
telling her father some extraordinary story concerning Kirk.  But the
Professor declined to listen; he trusted his friend implicitly."

"And foolishly so," I remarked.

"Very, for since that I gained knowledge that Kirk, rather than being my
master's friend, was his bitterest enemy.  Miss Ethelwynn was the first
to discover it.  She has been devoted to her father ever since the death
of the poor signora."

"But how do you account for that remarkable occurrence behind those
locked doors?"  I asked, as we stood there in the corner, with the gay
chatter of the society of Rome about us; an incongruous situation,
surely.  "What is your theory?"

"Ah, signore, I have none," he declared emphatically.  "How can I have?
It is a complete mystery."

"Yes; one equally extraordinary is the fact that Miss Ethelwynn, who was
seen by us dead and cold, is yet still alive."

"Alive!" he gasped, with a quick start which showed me that his surprise
was genuine.  "I--I really cannot believe you, Signor Holford!  What
proof have you?  Why, both you and Kirk declared that she was dead!"

"The proof I have is quite conclusive.  Leonard Langton spoke to her on
the telephone to Broadstairs, and he is now down there with her."

"Impossible, signore!" declared the man, shaking his head dubiously.

"When did you last see her?"

"She was lying on the couch in the diningroom, as you saw, but at Kirk's
orders she was removed from the house in a four-wheeled cab.  I
explained to the cabman that she was unwell, as she had unfortunately
taken too much wine.  Some man--a friend of Kirk's--went with her."

"And what was their destination?"  I demanded.

"Ah, signore, I do not know."

"Now, Antonio, please do not lie," I said reproachfully.  "You know
quite well that your master's daughter was removed to a certain house in
Foley Street, Tottenham Court Road."

"Why," he exclaimed, turning slightly pale, and staring at me, "how did
you know that?"

I laughed, refusing to satisfy his curiosity.  In his excitement his
accent had become more marked.

"Well," he said at last, "what does it matter if the signorina is still
alive, as you say?  For my own part, I refuse to believe it until I see
her in the flesh with my own eyes."

"Well," I remarked, "all this is beside the mark, Antonio.  I have
understood from everyone that you were the devoted and trusted servant
of Professor Greer, therefore you surely, as a man of honour, should
endeavour to assist in clearing up the mystery, and bringing the real
assassin to justice."

The man sighed, saying:

"I fear, signore, that will never be accomplished.  The mystery has
ramifications so wide that one cannot untangle its threads.  But," he
added, after a slight pause, "would you object to telling me how you
first became acquainted with Signor Kirk?"

Deeming it best to humour this man, who undoubtedly possessed certain
secret knowledge, I briefly described the means by which Kirk had sought
my friendship.  And as I did so, I could see the slight smile at the
corner of his tightened lips, a smile of satisfaction, it seemed, at the
ingenious manner in which I had been misled by his friend.

"Then he brought you to Sussex Place on purpose to show you the dead
body of my master?"

"He did.  I had no desire to be mixed up in any such affair, only he
begged me to stand his friend, at the same time protesting his
innocence."

"His innocence!" exclaimed the Italian fiercely between his clenched
teeth.

"You believe him guilty, then?"  I cried, quick to notice his lapse of
attitude.

"Ah, no, signore," he responded, recovering himself the next second, a
bland smile overspreading his dark, complex countenance.  "You
misunderstand me; I suspect nobody."

"But you had a more intimate knowledge of the household, and of the
Professor's friends, than anyone else.  Therefore you, surely, have your
own suspicions?"

"No; until one point of the mystery, which has apparently never occurred
to you, has been cleared up, both you and I can only remain in
ignorance, as we are at present."

"Why not be quite frank with me, Antonio?"  I urged.  "I do not believe
you are your master's assassin; I will never believe that!  But you are
not open with me.  Put yourself in my place.  I have been entrapped by
Kirk into a network of mystery and tragedy, and have lost my wife, who,
I fear, is in the hands of conspirators.  I have not been to the police,
because Kirk urged me not to seek their aid.  So--"

"No, signore," he interrupted quickly, "do not tell the police anything.
It would be injudicious--fatal!"

"Ah!"  I cried, "then you are acting in conjunction with Kirk?  You,
too, are trying to mislead me!"

"I am not, signore," he protested.  "On the tomb of my mother," he
declared, making use of the common Italian oath, "I am only acting in
your interests.  The disappearance of your signora adds mystery to the
affair."

"What do you suggest as my next move?  If I find Mabel, I care nothing.
The tragic affair may remain a mystery for ever.  I leave it to others
to discover who killed Professor Greer."

"You actually mean that, signore?" he cried.  "You would really refrain
from seeking further, providing you rediscover your wife?"

I was silent a few seconds.  His eagerness was sufficient admission of a
guilty conscience.

"Yes," I said.  "What matter the affairs of others, so long as the wife
I love is innocent and at my side?  She is the victim of a plot from
which I must rescue her."

The Italian gazed again away across the roofs of the Eternal City, now
growing more indistinct in the gathering mists.

"I fear, Signor Holford," he at last exclaimed with a sigh, "that you
have a very difficult task before you.  You are evidently in ignorance
of certain curious facts."

"Concerning what?"

"Concerning your wife."

"You would cast a slur upon her good name?"  I cried excitedly, my anger
rising.

"Not at all," was his calm, polite response, his lips parted in a
pleasant smile.  "You asked me to assist you, and I was about to give
you advice--that is, provided that you have told me the truth."

"About what?"

"About Miss Ethelwynn--that she still lives."

"Of that there is no doubt," I said.

"And if you found your signora alive and well, you would undertake to
make no further inquiry?" he repeated, with undue eagerness.

"Ah!  You wish to tie me down to that?"  I cried.  "You do so because
you and your friends are in fear.  You realise your own peril--eh?"

"No," declared the man at my side; "you still entirely misunderstand me.
You are an Englishman, and you mistrust me merely because I am a
foreigner.  It is a prejudice all you English have, more or less."

"I entertain no prejudice," I declared hotly.  "But to tell you the
truth, Antonio, I am tired of all this mystery, and now that Kirk and
his friends have alienated me from my wife, I intend to take action."

"In what manner?" he asked calmly.

"I shall go to the Questore here, in Rome, and tell the truth.  I happen
to know him personally."

"And you will mention my name!" he gasped, well knowing probably the
drastic measures adopted by the police of his own country.

"I shall not be able to avoid mentioning it," I responded, with a smile.

"_Bene_!" he answered, in a hard, hoarse voice.  "And if you did--well,
signore, I can promise that you would never again see your signora
alive.  Go to the Questore now!  Tell him all you know!  Apply for my
arrest!  And then wait the disaster that must fall upon you, and upon
your missing wife.  An unseen hand struck Professor Greer--an unseen
hand will most assuredly strike you, as swiftly, as unerringly."  And
then facing me defiantly, a grin upon his sinister face, the fellow
added: "Silence, signore, is your only guarantee of safety--I assure
you!"

CHAPTER SEVENTEEN.

ETHELWYNN SPEAKS.

I looked into the closely-set, crafty eyes of the old Italian, and saw
both determination and desperation.

Was he the man who killed Professor Greer?

"I require no guarantee of safety from you, Antonio," I answered
quickly.  "I am now solely in search of my wife.  Where is she?"

"Caro signore, I have no idea," was the old fellow's bland reply, as he
exhibited his palms.  "I have not the pleasure of the signora's
acquaintance."

"But you know where Kirk is hiding, and she is with him, assisting him
in discovering my whereabouts, I believe!"  I cried.

"That the Signor Kirk crossed from Dover to Calais I am well aware, but
of his movements afterwards I assure you I am in complete ignorance."

What could I do further?

He professed to be equally mystified with myself regarding my wife's
disappearance, declaring his readiness and anxiety to assist me if it
were possible.

Then, in the falling twilight, we slowly descended the road together, he
giving me his address in the Via Tordinona, a side street close to the
Bridge of Sant' Angelo, which I noted on my shirt-cuff.  At the Porto
del Popolo we parted, and I returned to the hotel to dine with Gwen,
whom I found awaiting me in feverish expectation.  I told her briefly of
my meeting with a man I knew, but explained nothing of his connection
with the house in Sussex Place, nor of the secret tragedy that had been
enacted.

Next day was the fifth of February, the day of Santa Agata.  How well I
recollect it, for at noon we bade farewell to the Eternal City, and as
the train roared on across those wide, dreary marshes of the Maremma on
our journey northward, I sat in the corner of the compartment and made
up my mind to go direct and seek Ethelwynn, the girl whom I had seen
dead, and who was yet alive.

I recalled all Antonio's ominous statements; how that he had expressed a
doubt whether the professor's assassin would ever be brought to justice,
and how he had threatened that, if I betrayed the truth to the police, I
should never again meet Mabel alive.  Did not those words of his
conclusively prove complicity in the affair?  Why did he command my
silence at peril of my dear wife's life.  He had lied when he told me
that he was ignorant of her whereabouts; but if he were the actual
assassin, or even one of the accomplices, I saw that I could hope for no
assistance from him.  It was that conclusion which caused me to resolve
to invoke the aid of the girl whom I had seen lying upon the floor, cold
and lifeless.

From Rome to Broadstairs is a far cry, but two days later we alighted at
Victoria, and on the morning of the third day I found myself at the door
of a pretty newly-built red-roofed house standing in its own ground high
upon the cliffs between the Grand Hotel at Broadstairs and Dumpton Gap.

A neat maid opened the door, and, on inquiring for Miss Greer, I was
shown across a square, ample hall to a small cosy sitting-room
overlooking the sea, facing direct upon the treacherous Goodwins.

The maid who took my card returned to say that her mistress would be
with me in a few moments.  And then I stood at the window, gazing along
at the quaint old-world harbour of Broadstairs, with "Bleak House"
standing high beyond, full of keen anxiety as to the result of the
interview.

She came at last, a tall, slim figure, in a dark stuff skirt and cream
silk blouse, relieved by a touch of colour at the throat, a sweet-faced,
fair-haired, delicate girl, whose large blue eyes wore a look of wonder
at the visit of a stranger.  She whom I had seen a corpse was certainly
alive, and living here in the flesh!

"I must apologise for this intrusion, Miss Greer," I began, for want of
something better to say, "but I may introduce myself as an acquaintance
of Mr. Langton--an acquaintance under somewhat romantic and curious
circumstances."

"Mr. Langton has already told me how he met you--when he believed there
were burglars in our house in Sussex Place," she said, with a
brightening smile.

"Yes," I replied.  "I--well, I was put there on guard, but Mr. Langton's
suspicions fortunately proved to be unfounded."

"Ah!" she said, with just the slightest suspicion of a sigh.  "I'm glad
of that--very glad!"

"The reason of my visit, Miss Greer, is," I explained after a brief
pause, "to ask you whether you are aware of the whereabouts of my
friend, your father?"  And I fixed my eyes straight upon hers.

"My father went to Scotland," she replied, without wavering.  "At
present he's in Germany.  The last I heard of him was three days ago,
when he was in Strassburg."

"He wrote to you?"  I gasped, staring at her in amazement that this
ready lie should be upon her lips.

She noted my surprise, and said:

"Yes, why shouldn't he?"

What reply could I give?  Could I tell her that the Professor, her
father, had been cruelly done to death, and his body cremated in his own
experimental furnace?  Had I not given my word of honour to that weird
will-o'-the-wisp, Kershaw Kirk, that I would preserve silence?  Besides,
my only thought was for my own dear wife, whose face now rose ever
before me.

"Well," I stammered.  "I--well--I believed that you were unaware of his
whereabouts, Miss Greer.  At least, I understood so from your father's
butler, Antonio."

She smiled, regarding me quite calmly.  She was either in ignorance of
what had occurred, or else she was a most perfect actress.

Yet how could she feign ignorance?  Had not Kirk told me that she had
thrown herself upon her knees before her father's body, vowing a fierce,
bitter vengeance upon his assassin?  Perhaps Kirk had lied, of course,
yet I recollected that the discovery had been made while the dead man's
daughter was in the house, and that after the astounding incident she
had removed with Morgan, her maid, to Lady Mellor's, while the other
servants--unaware of what had occurred--had either been sent away down
to Broadstairs, or else discharged.  In secret, this handsome girl
before me--the girl with that perfect dimpled face and innocent blue
eyes--had returned, and we had found her lying apparently dead in the
dining-room.

Ethelwynn's present attitude of pretended ignorance of her father's fate
struck me as both amazing and culpable.

"You say that the Professor was in Strassburg?"  I said.  "Is he still
there?"

"As far as I know," she replied, twisting her rings nervously around her
thin white finger.

"Could I telegraph to him?"  I ventured to suggest.

"Certainly, if you have business with him," she responded.  "I'll go and
get the address."  And she swiftly left the room, leaving on the air a
sweet breath of violets, a bunch of which she wore in her belt.

A few minutes later she returned with a letter in her hand.

"His address is Kronenburger Strasse, number fifteen," she exclaimed.
"Do you know Strassburg?  It's just at the corner, by the bridge over
the canal."

"I have never been in Strassburg," was my reply.  "But I have important
business with the Professor, so, with your permission, I will telegraph
to him from here."

"Most certainly," she said.  "He tells me that his affairs are likely to
keep him abroad for a considerable time.  But--" and she paused.  At
last she added: "I have never heard him speak of you as a friend, Mr.--
Mr. Holford."

"Perhaps not," I said quickly.  "The fact is, I'm a confidential friend
of his, as well as of Mr. Kershaw Kirk."

"A friend of Mr. Kirk!" she cried, staring at me with a startled
expression, half of fear and half of surprise.

"Yes," I said.  "I believe Mr. Kirk is an intimate friend both of your
father and yourself.  Is not that so?"

"Certainly.  He's our very best friend.  Both Dad and I trust him
implicitly," replied the girl.  "Indeed, during my father's absence he
is left in charge of my affairs."

For a moment I remained silent.

"He is your friend--eh?"

"Certainly.  Why do you ask?"

"Well, because I feared that he was not your friend," I answered.  "Do
you happen to know his whereabouts?"

"He's abroad somewhere, but where I don't know."

"Ah!"  I laughed lightly, in pretence of careless irresponsibility.  "He
has always struck me as a strange figure, ever mysterious and ever
evasive.  Who and what is he?"

"You probably know as much of him, Mr. Holford, as I do," was the girl's
answer.  "I only know him to be an intimate friend of my father, and the
ideal of an English gentleman.  Of his profession, or of his past, I
know nothing.  My father, who knows him intimately, is always silent
upon that point."

I noted that she spoke in the present tense, as though to preserve the
fiction that her father was still alive.  Ah! this girl with the
innocent eyes and the wonderful hair, the beloved of young Leonard
Langton, was an admirable actress, without a doubt.  Without the tremble
of an eyelid, or the movement of a muscle of the mouth, she had actually
declared to me that Professor Greer was still alive!

"To me, Kirk is a mystery," I declared, my gaze fixed straight into her
eyes as I stood near the window where the wintry sunlight from across
the sea fell full upon her; "at times I doubt him."

"And so does Mr. Langton," she responded.  "But I think that the fears
of both of you are quite groundless.  Mr. Kirk is a little eccentric,
that's all."

"When did you first know him?"  I inquired.

"Oh, when I came back from Lausanne, where I had been at school, I found
him to be my father's most trusted friend.  They used to spend many
evenings together in the study, smoking and discussing abstruse points
of foreign politics in which I, a woman, have no interest."

"And has he always showed friendship towards you, Miss Greer?"  I asked.

"Oh, yes, and to Leonard also, though of late I fear there has been some
little unpleasantness between them."

At this I pricked my ears.  I recollected that young Langton had, to me,
pretended ignorance of the very existence of Kershaw Kirk!  What was the
meaning of his attitude towards the man whom I had so foolishly allowed
to escape, and who had repaid my friendship by inducing my wife to
travel upon a fool's errand, and, as I feared, fall into a fatal trap
laid open for her?

Antonio had covertly threatened me, and I knew instinctively that my
well-beloved Mabel was now in direst peril.  Ah! that wild fevered life
I was now leading was one continuous whirl of dread, of suspicion, and
of dark despair.

"You have actual knowledge that Mr. Langton has quarrelled with Kirk?"
I asked at last.

"Yes, and I much regret it, for Mr. Kirk has been our very good friend
throughout.  It was he who urged my father to allow Mr. Langton to pay
court to me," she added.  "It was he who made the suggestion that we
might be allowed to marry.  Such being the case, how can I think ill of
the eccentric old fellow?"

"Of course not," I said, "but is your trust really well founded, do you
think?  Are you quite certain that he is your friend, or only your
pretended ally?"

"I am quite certain," she declared, "I have had proof abundant of it."

"Your father did not, I believe, tell you of his projected visit to
Germany before leaving?"

"No," was her reply.  "He went up to Edinburgh, but after having left me
was suddenly compelled to alter his plans.  He crossed to the Hook of
Holland, travelling from York to Harwich without returning to London."

"This he has told you?"

"Yes, in a letter he wrote from Cologne.  I wanted to join him, but he
would not allow me, and ordered me to come down here.  He is very busy
concerning one of his recent discoveries."

"Ah!"  I sighed.  "He would not allow you to go to him, eh?"

"No; he made excuse that the weather was better just now in Broadstairs
than in Southern Germany, and said that his future movements were very
uncertain, and that he could not be hampered by a woman."

In that reply I recognised an evasiveness which was natural.  The
Professor himself was dead, and this mysterious person posing as him
was, of course, disinclined to meet Ethelwynn face to face.

Yet that even surely did not affect the girl's amazing attitude?  She
herself had seen her father dead, yet was now actually assisting the
impostor to keep up the fiction that he was still alive!

CHAPTER EIGHTEEN.

I DRAW THE IMPOSTOR.

Having invented a story of a secret business friendship with the
Professor, I remained with his pretty daughter for perhaps a quarter of
an hour longer.

From her I further learned that Leonard Langton was now back in London,
and that Kirk had written her implicit instructions to remain at
Broadstairs for the present.

Then I bade her farewell, and walked back along the cliffs, past the
Grand Hotel, to the quaint parade of the old-fashioned little
watering-place, turning up to the chemist's shop, which is, at the same
time, the post-office.

Thence I dispatched a telegram addressed to Professor Greer at the
address in Strassburg which his daughter had given me, appending Kirk's
name, and asking for a reply to be sent to the Albion Hotel at
Broadstairs, where I intended staying.

Afterwards I strolled to the hotel, ate my luncheon, and idled along the
deserted jetty and promenade throughout the bleak, bright afternoon in
eager expectation of a response from the impostor.  My thought was ever
on my dear lost Mabel.  Fettered by ignorance and mystery, I knew not in
which direction to search, nor could I discern any motive by which we
should be thus parted.

My tea I took in the hotel, and afterwards smoked a cigar, until just
before six the waiter handed me a message, a brief reply to mine, which
read:

"Why are you running risks in Broadstairs, when you should be elsewhere?
Be judicious and leave.--Greer."

I read the message over a dozen times.  What risks could Kirk be running
by coming to Broadstairs?  Was not that telegram essentially a word of
warning given by one accomplice to another?

And yet Ethelwynn trusted Kirk just as blindly and foolishly as her
father had done.

But was not the truth a strange one?  She had concealed from me, as she
was concealing from the world, that the Professor had died at the hand
of an unknown assassin.

Or was it that she herself was an accomplice?

No, I could never believe that.  I refused to give credence to any such
suggestion.

I ascended the long hill to Broadstairs Station, and half an hour later
left for Victoria.  My intention was to go direct to Strassburg and
there to discover and unmask the impostor.  But ere I reached London the
night mail for the Continent had already left Charing Cross, so I took a
taxicab to my lonely home, where Gwen was awaiting me, still anxious and
expectant.

I told her of the fruitlessness of my errand, whereupon she sank back
into her chair, staring straight into the fire.

In brief I explained that I had discovered the existence of a person in
Strassburg who could probably give me a clue to the whereabouts of Kirk
and Mabel.  Hence my intention of departing by the first service next
morning.

"Cannot you telegraph and ask?" suggested the girl.  "We seem, Harry, to
be losing so much time," she added frantically.  "You haven't been to
the police."

"I know, Gwen," I said in sorrow, "but I can't do more.  To telegraph
further might close the channel of our inquiry.  No, we must still
remain patient."

Then, after snatching some food which had been left in the dining-room
for me, I swallowed a glass of burgundy and entered the small room which
I used as my particular den.

From there I rang up Pelham on the telephone, and heard the latest
details concerning the business which I was now sadly neglecting.
Afterwards I sat down and wrote an advertisement for the _Times_, an
appeal addressed to "Silence" for news of my lost wife, an appeal which
at the same time contained a veiled threat of exposure of the affair in
Sussex Place.

This I concluded, and, ringing up an express messenger, dispatched it to
the advertisement offices of the paper.

Then, with sudden resolve, I went forth to Wimpole Street to call upon
Leonard Langton.

I found him in his cosy, well-furnished chambers, busy writing letters,
while the round-faced man seated in a big arm-chair by the fire smoking
a pipe he introduced as his chum with whom he shared chambers, Doctor
Hamilton Flynn.

"Flynn's a specialist on the nose and throat," he laughed.  "He has his
consulting rooms along in Harley Street, and we pig it here together."

"Jolly comfortable quarters," I remarked, glancing round.  "I called
here before, but you were out."

"Yes, so sorry!" he exclaimed.  "Sit down and have a cigar," and he
handed me a box of most excellent weeds.

"Well," exclaimed the smart young fellow who was the confidential
secretary of Sir Albert Oppenheim, "I'm really glad to see you again,
Mr. Holford.  That was a most mysterious incident at Sussex Place the
other evening," he added.  "I'm still convinced that somebody was in the
house.  The Professor's furnace was alight, you recollect, and the
laboratory door stood open."

"Langton has told me all about it," remarked the doctor in a deep voice;
"very curious, it seems."

"Most extraordinary," I declared, "and the more so that Merli, the
butler, should have suddenly disappeared.  The other day I met him in
Rome."

"Met Antonio!" gasped Ethelwynn's lover, staring at me in amazement.
"Have you been to Italy?"

"Yes.  I told him of our search, but he declared himself ignorant of
everything, though he admitted having seen you passing through the
buffet at Calais-Maritime."

"What is he doing in Rome?"

"I have no idea; I was there in a vain endeavour to recover my lost
wife.  She has been misled by a forged telegram purporting to come from
myself, and is somewhere on the Continent.  Where, however, I cannot
tell."

"You've lost your wife, eh?" asked the doctor, glancing strangely across
at his companion, I thought.  His face was dark and aquiline, his
shoulders sloped.  He was not a man to be trusted.  "You think she's
been tricked?" he added.  "Why?"

"Ah, at present I can form no theory as to the motive.  If I could I
might perchance discover the person responsible for her disappearance,"
and I briefly told him of my frantic journey to the Italian capital.

"And now I am going to Strassburg tomorrow," I added.

"Why to Strassburg?" inquired Doctor Flynn, regarding me fixedly with
those keen eyes of his.

"Because Professor Greer is there, and I have an idea that he can tell
me something."

"The Professor is no longer there," was Langton's quick interruption.
"Half an hour ago I spoke to Ethelwynn on the telephone, and she told me
that she had just heard by telegraph from her father that he had left
for Linz on his way to Hungary."

My heart fell within me.  Evidently my telegram signed Kirk had scared
the man passing himself off as the Professor.

"But I might go on to Linz, or catch him up somewhere in Hungary," I
suggested.

"It would be futile, my dear fellow," said Langton.

"Why?"

"Well, just at present Professor Greer wishes to be left entirely alone
by his friends."

"But there must be some reason," I cried, for there seemed on every hand
to be a conspiracy of silence again me.

"There is a reason," replied the young man in a low, calm voice, "one
which, however, seems mysterious."

"Ah!"  I cried.  "Then even you are mystified by these strange
happenings?"

"Yes," he replied, knocking the ash from his cigar, "I have had certain
suspicions aroused, Holford--vague suspicions of something wrong in the
Professor's household.  Antonio is absent, the servants have all been
paid and dispersed, the house in Sussex place is closed, and--"

"And the Professor is a fugitive, fleeing towards Hungary," I added.
"Has not Miss Ethelwynn told you anything?"

"What she has told me has been in complete confidence.  It has caused me
a great deal of surprise and apprehension, Holford, and this surprise
has been increased by what you have told me this evening--that your wife
has been enticed away, and is missing."

"But what connection can my wife possibly have with any occurrence at
the house of Professor Greer?"  I demanded.  "She was in ignorance of
everything.  She was not even acquainted with Greer.  I might tell you
that to-day I have been down to Broadstairs and seen Miss Ethelwynn," I
added.

"Ethelwynn did not seem to remember ever having met you when I told her
of our encounter at the door, and the subsequent events."

"I am a friend of the Professor's, not of his daughter," I hastened to
explain.  "But are you absolutely certain that a journey to Strassburg
to-morrow would be useless?"

"Absolutely.  If Greer consented to see his friends I would be the first
to see him."

"And he has refused even you, eh?"  I asked, smiling within myself at
the superior knowledge I possessed.

"He has.  He refuses, too, to allow his daughter to go to him."

"But why?"  I asked.

"For reasons known, I suppose, to himself."

"Does he give none?"

"He vaguely answers that certain matters concerning a great scientific
discovery he has made compel him at present to hold aloof from both
family and friends.  He fears, I think, that someone who has discovered
his secret may betray it."

"But surely Ethelwynn would not?"  I cried.  "I desire to see the
Professor because I feel confident he can, if he will, explain the
motive of the trap into which my wife has fallen."

"If he refuses to see his own daughter he will hardly see you," remarked
the dark-faced doctor.  "Under exactly what circumstances has Mrs.
Holford disappeared?"

I briefly explained, at the same time regarding the round-shouldered
specialist with some antagonism.  To me, it appeared as though he were
erecting an invisible barrier between myself and the knowledge of the
truth.  He seemed entirely Langton's friend, corroborating his every
word.

And the more curious became his attitude when at last I remarked with
firm and resolute air:

"Well, if Professor Greer refuses to see me, then I shall invoke the aid
of the police.  They will probably very soon discover him, wherever he
may be."

"I hardly think that would be a wise policy," remarked Flynn, tossing
his cigar-end into the fire, and rising quickly from his chair, "unless,
of course, you could make some direct charge against him."

I was silent for a moment.

"And if I did?  What then?"  I asked, speaking boldly in a clear voice,
my eyes fixed upon his, for remember I was fighting for knowledge of my
dear wife's whereabouts.

"Well--if you did," was his deliberate reply, "it would be you yourself
that would suffer, Mr. Holford, and no one else."

Was it not astounding, startling?

This doctor, the bosom friend of Ethelwynn's lover, had given me exactly
the same threatening reply as Antonio had given me on the Pincian in
Rome.

What could it mean?  The reason why the false Professor was avoiding
friends and enemies alike was, of course, sufficiently plain to me.  But
for what reason was my well-beloved Mabel, the loving wife whom I
adored, held in the unscrupulous hands of those who killed Professor
Greer?

And why was every effort of mine to discover her met only by threats of
impending disaster?

I gazed at the two men before me in silent defiance.

If it cost me my own life I intended to discover her and hold her dear
form once again in my arms.

She was mine--mine before God and before man; and these persons seeking
for some mysterious motive to shield the false Professor should not
further stand in the way of justice.

"You think I dare not go to the police!"  I cried at last.  "Very well,
if you care to come with me to Scotland Yard now--for I am going
straight there--I will, in the presence of both of you, unfold a strange
tale which they'll be very much surprised to hear."

"You believe you know the truth!" laughed Langton.  "No, my dear
Holford.  Don't be such a fool!  The police cannot help in this affair,
for the mystery is far too complicated.  Keep your own counsel."

"Yes," I sneered, "and depend upon the man of whom you have denied all
knowledge--the man Kershaw Kirk."

"Kershaw Kirk!" gasped the doctor, and I saw that he went pale, his dark
eyes starting from his head.  "Do you know him?  Is he--is he your
friend, Mr. Holford--or--_or your enemy_?"

CHAPTER NINETEEN.

GWEN REVEALS SOMETHING.

It struck me that this keen-eyed, crafty-faced, round-shouldered
specialist in diseases of the throat intended to profit by information
derived from me regarding the mysterious Kirk.  Why, I did not know.  We
all of us have at times a strange intuition of impending evil, one that
we cannot account for and cannot describe.

Recollect, I was only just an ordinary man, a hard-working industrious
dealer in motor-cars, a man who made a fair income, who was no romancer,
and was entirely devoted to his wife, who had, ever since his marriage,
been his best friend and adviser.

The Professor was a scientist, I remembered, and this man Hamilton Flynn
was apparently a doctor of some note.  Could there be any connection
between the pair, I wondered.  Flynn, Langton's most intimate friend,
was no doubt aware of much, if not all, that transpired in the
Professor's household.  That he knew Kershaw Kirk was apparent by his
surprise when I mentioned his name.

"Kirk is a mere acquaintance of mine," I responded, after a brief pause;
"whether he is my friend, or my enemy, remains to be seen."

"He's your enemy, depend upon that, Mr. Holford," declared Flynn
emphatically.  "He is a marvellously clever schemer, and the friend of
few."

I bit my lip.  Well did I know, alas! that the fellow whose asides to
his pet "Joseph" were so entertaining was not my friend.

It was upon my tongue to explain how the description of that man who was
travelling with my wife in search of me tallied with that of my strange
neighbour who had, with such subtle cunning, drawn me into that
mysterious tragedy.  But next second I hesitated.  This man Flynn I
mistrusted.  My impression was that he was not playing a straight game,
either with myself or with his friend Leonard Langton.

A thousand questions I had to ask those men--and Langton especially--but
I saw by their attitude that their intention was rather to mislead me
than to reveal anything.  When I presently bade them farewell neither of
them offered to assist me in my search for Mabel.

Therefore I went forth into the darkness and silence of Wimpole Street--
for it was now near midnight--and walked down into Oxford Street ere I
could find a taxi-cab to convey me back to my now cheerless home.

Lying awake that night, I decided to postpone my journey to Germany.  It
was evident that the impostor passing himself off as the Professor had
taken my telegram purporting to come from Kirk as a warning, and had
escaped.  I had been a fool to telegraph.  I should have gone there
instead.  His reason for keeping up the fiction that the Professor was
alive was, of course, obvious, for while he did so there would be no
inquiry into the whereabouts of the missing man.

I had made a promise to Kershaw Kirk, yet now that he had so grossly
deceived me, why should I keep it?  Why should I not tell the truth?

I reflected; there were, I saw, three reasons why I should still
preserve silence.  The first was because, after that lapse of time, I
should be suspected, perhaps arrested, as an accomplice and dragged
through a criminal court.  The second was that Ethelwynn herself was,
for some amazing reason, pretending that her father still lived; and the
third was by reason of the strange threat of Mabel's death uttered by
the evil-faced Italian, and repeated by that Harley Street specialist
who was Leonard Langton's closest friend.

The assassins were actually holding my dear wife as hostage against any
revelation I dared to make!  That, in a word, was the true position.

I paced my room that night in the agony of despair.  Of nothing did I
think but the dear, sweet-faced woman so suddenly enticed away from my
side by reason of her eagerness to meet me.  She was a woman of high
ideals and of lofty sentiments; a womanly woman who, though fond of a
little gaiety and of the theatre, realised that her place was in her own
home, where she reigned supreme.

Before my marriage my father, as fathers will, had looked upon her with
considerable misgiving.  She was a little too flighty, too fond of
dress, of dinners, and dances, he had said.  But after our wedding and
our honeymoon spent in a car touring up in Scotland, she had settled
down, and never for a single instant had I regretted my choice.  Few men
could say that.

Indeed, up to that day when Kershaw Kirk called to inspect the Eckhardt
tyre, I was one of the happiest men in all London; prosperous in my
business, and contented in my love.

Now, alas! all had changed.  I was obsessed by the knowledge of a great
and startling secret, and at the same time I had lost all that to me was
most dear and cherished.

Next morning Gwen, fresh in her clean cotton blouse, and the big black
bow in her hair, sat in her accustomed place at the breakfast table, but
after greeting me lapsed into a thoughtful silence.

At last she asked: "Have you packed your things, Harry?"

"Oh, I forgot to tell you!"  I exclaimed.  "I'm not going to-day.  I've
changed my mind."

"Not going?  Why, I thought you intended to see the Professor in
Strassburg?" she cried.

"He has left," I sighed; "I learned last night that he is on his way to
Hungary."

"And will you not follow?" asked the girl in reproach.  "Will you not
try to discover where Mabel is?"

"I've tried, Gwen--and failed," I answered despairingly.

"You have not told me all, Harry," she said, looking across at me.  At
the head of the table was Mabel's empty place.  "You have concealed
something from me," she declared.

"It is nothing that you should know," was my quick reply.  "My own
private business does not concern you, Gwen--or Mabel either."

"But surely I ought to know the truth?  Mabel has been decoyed away
abroad, and there must be some motive for it," she replied in bitter
complaint.

"Of course, my dear girl, but even I, in the knowledge of what has
passed, cannot discern what the motive can be.  If I could, all would be
plain sailing, and we would soon recover her," I said.

"Who is this Professor of whom you have spoken?" she asked, leaning her
elbows upon the table, and gazing straight into my eyes.

"Professor Greer, the well-known chemist."

"Greer?" echoed the girl, staring at me strangely.

"Yes, why?"

But she hesitated, as though disinclined to tell me something which was
upon her mind.

"You know the Professor, eh, Harry?"

"I've met him once," I replied, which was perfectly true.

"And only once?" she asked.

"Only once," was my quick response.

"That's curious."

"Why?"

"Well--well, I suppose I ought not to tell you, for, of course, Harry--
it's no business of mine," remarked the girl, "but as Mabel is now
missing, no fact should be concealed, and I think you really ought to
know that--"

"That what?"  I cried.  "Tell me quickly, Gwen!  Conceal nothing from
me!"

"Well, that Mabel one morning received a note delivered by express
messenger, and I asked her whom it was from.  She seemed unusually
flurried, and told me that it was from Professor Greer."

"But she never knew him!"  I gasped.  "What day was that?"

"The day before you returned from Glasgow."

"The same day on which she received that telegram from Italy purporting
to be signed by me!"

I exclaimed.  "Why didn't you tell me this before, Gwen?"

"Mabel's affairs have nothing to do with me.  I am not interested in her
correspondents, Harry," she replied.  "Surely it is not my place to
carry tales to you, is it?"

"No; pardon me," I said, hastening to excuse myself, "but in this affair
the truth must be told."

"Then why haven't you told it to me?" asked the girl.  "Why are you so
carefully hiding other facts?"

"Because they are of concern only to myself--a secret which is mine, and
mine alone."

"And it does not concern Mabel?" she demanded.

"No," I replied hoarsely, "except that her acquaintance with the
Professor has placed a new phase upon the mystery.  Tell me all that
happened concerning that note."

"It came about eleven o'clock in the morning," she said.  "I saw a
telegraph-boy come up the steps, and believed he had a message from you.
Annie took the note and brought it here into the dining-room, where
Mabel signed for it.  She read it through, and I saw that it caused her
a great shock of surprise.  Her hands were trembling.  I inquired what
was the matter, but she made some evasive reply.  I demanded to know
whom it was from, and she replied that her correspondent's name was
Greer.  `He ought never to have written to me,' she added.  `Men are
sometimes most injudicious.'  Then she rose and placed the letter in the
flames, watching it until it had been burned."

"And is that all?"  I demanded, astounded at the girl's story.

"Yes, except that for some hours afterwards she seemed very upset.  To
me it appeared as though she had received word of some unusual
occurrence.  At noon she called a taxi by telephone, and went out.  She
did not return for luncheon, so I was alone.  At three she came back,
and I saw that she looked pale and distressed, while her eyes were red,
as though she had been crying.  But I attributed that to our ignorance
of where you were.  You know, Harry, how upset she is if when you are
away you don't write or wire to her every day," added the girl.

The story held me utterly speechless.  That Mabel was acquainted in
secret with the Professor astounded me.  But it had been the false
Professor who had written to her.  Possibly the fellow was already in
London while I was searching for him in Glasgow, and, if so, what was
more probable than that she should have met him by appointment?

Not one single instant did I doubt Mabel's truth and love.  If she had
met this impostor, then she had been the victim of some cleverly-planned
plot.  I was incensed only against the perpetrators of that foul crime
in Sussex Place, not against the sweet, soft-spoken woman who was so
near my heart.  Mabel was my wife, my love, my all-in-all.

Poor Gwen, watching my face intently, believed that she had acted as a
sneak towards her sister, but I quickly reassured her that it was not
so.  Her revelations had sent my thoughts into a different channel.

"The telegram summoning her to Italy came after her return?"  I asked.

"Yes, she was upset, and would eat no tea," the girl answered.  "Her
conversation was all the time of you.  `Harry is in danger,' she said
several times.  `Something tells me that he is in the greatest danger.'
Then, when the message came, she became almost frantic in her anxiety
for your welfare, saying, `Did I not tell you so?  My husband is in
peril.  He is the victim of a plot!'"

"You never heard her speak of the Professor before?"  I inquired.

"Never, Harry; and, truth to tell, I was surprised that she should
receive a letter from a man who she admitted to me was unknown to you."

"She told you that?"  I cried.

"She said that you were not acquainted with the Professor, and that you
might object to him writing to her, if you knew."

"Then she was in fear of discovery, eh?"  I asked in a husky voice.

"Yes," faltered the girl.  "It--it almost seemed as though she was.  But
really, Harry, I--I know I've done wrong to tell you all this.  I--I'm
quite ashamed of myself.  But it is because I am in such great fear that
something has happened to my sister."

"You have done quite right, Gwen," I assured her.  "The circumstances
have warranted your outspokenness.  Some men might perhaps misjudge
their wives in such a case, but I love Mabel, and she loves me.
Therefore I will believe no ill of her.  She is the innocent victim of a
plot, and by Heaven!"  I cried fiercely, "while I live I'll devote my
whole life to its exposure, and to the just punishment of any who have
dared to harm her!"

CHAPTER TWENTY.

ONE TRAVELLER RETURNS.

One fact was quite plain.  It was the false Professor who had written to
my wife.  For aught I knew, the man whom I had followed from Edinburgh
to Glasgow might have already been in London, and she might have met him
by appointment.

During the morning I took the "forty-eight," and ran over to Regent's
Park, passing slowly before both front and back of the house in Sussex
Place.  The blinds were up, but from the condition of the doorsteps it
was plain that the place was tenantless.

From the "London Directory" I obtained the number of Lady Mellor's, in
Upper Brook Street, and called.  The fat butler told me that Morgan,
Miss Greer's maid, had left with her mistress, and as far as he knew was
down at Broadstairs with her.  Her ladyship was at Bordighera.

I inquired if he knew anything of the other servants at Professor
Greer's.

"No, nothing," was the man's answer.  "At least, nothing except that the
Professor went abroad suddenly, and that they were all discharged and
given wages in lieu of notice."

"That Italian fellow discharged them, didn't he?"  I asked.

"Yes, sir.  I never liked him.  He's gone abroad with his master, they
say, and they've left a caretaker in charge."

"Oh, there is someone there, eh?"

"Yes, a policeman named Murphy and his wife.  They used to take care of
this house for her ladyship, and Miss Ethelwynn has now given her
father's house over to them.  They're a very steady pair, and live on
the premises."

Surely it was a master-stroke of the girl's to give over to the police
that house of tragedy!  Why was she concealing the fact of her father's
death?

I drove back to Chiswick with that one thought uppermost in my mind.

That afternoon I sat in my own office trying to attend to the details of
a business too long neglected, and listening mechanically to Pelham, to
Dick Drake, and to the others in my employment, who were complaining of
the unsatisfactory trials of a new car I had recently purchased.

Professor Greer was dead, and every trace of the crime removed, save for
those grim, indisputable relics which I had recovered from the ashes and
now held most sacred.  But further, my dear wife, whose knowledge of the
impostor was so amazing, was also missing.

The one point which, I confess, caused me some qualms, was the reason
why, not discovering me, she had not telegraphed to Gwen.  That, surely,
would be her first thought.  If she had missed me, she would surely have
let either Gwen or Pelham know.

Hence I could only think that she had either fallen into some fatal
trap--and there are many in the by-ways of certain Continental cities--
or else she was forcibly held from communicating with the outer world.
If so, by whom?  Probably by the Professor's false friend, Kershaw Kirk.

I could not put away from my mind the curious altitude of Hamilton
Flynn.  Why had he endeavoured to frighten me from going to Scotland
Yard?  What motive had he in this?  In what manner was he assisting his
friend, Leonard Langton?

Again, was Langton in ignorance of the Professor's end, or had he
knowledge of it, and was it by his persuasion that his beloved was so
cleverly feigning ignorance of all the past?

I began to suspect that these two men, bosom chums that they were, had
some hidden motive for concealing the Professor's death.  Yet, after
all, the point most amazing was the reason why, in the face of facts now
revealed, my mysterious neighbour should have taken such pains to reveal
the truth to me.

That evening, after a hasty meal at home with Gwen, I went back to the
garage, put on a greasy engineer's suit which I sometimes wore when
doing dirty work around the cars, and buttoned over it a frayed tweed
coat belonging to one of the men.  Then, with a cap on and a pipe in my
mouth, I went forth, and made my way on the top of a motor-'bus to the
corner of Wimpole Street.

If Flynn went out I intended to watch his proceedings, for though I
entertained only a vague suspicion of Langton, yet I felt confident that
his friend was not acting squarely.

Have you ever been seized with misgivings of a person whom you have no
just cause to doubt?  Is not such a feeling the result of some unseen
evil influence radiating from the person suspected--often quite rightly?

My first impression of this specialist in diseases of the throat and
nose was a bad one.

Therefore, I strolled up the long, eminently respectable street,
crossing Wigmore Street and Queen Anne Street, until a few doors on the
left before coming into Great Marylebone Street, I halted before the
house wherein the pair shared chambers.

There were bright lights in their big sitting-room on the first floor,
the room wherein Flynn had made those covert threats.  It was then
half-past eight.  They would have dined by that hour, and if they were
going out they would certainly very soon make an appearance.

I strolled to the corner of Great Marylebone Street, and idled at the
corner, watching.  The evening was bright and cold, and many cabs were
passing and repassing.  I lit my pipe, and sauntered up and down, my eye
ever upon the front door of the house wherein the two men lived.

The time hung heavily, as it ever does when one is watching.  An hour
dragged by, but no one came out.  At last, however, a maid ran up the
area steps and came in my direction with a letter in her hand ready for
posting in the pillar-box near which I was standing.

As she stopped I spoke to her, but at first she hesitated to answer.
After slipping five shillings into her hand, however, I induced her to
tell me that the doctor had dined alone, and was sitting upstairs.  Mr.
Langton had, she said, left London early in the afternoon, but she was
unaware of where he had gone.

"Tell me," I asked the girl, "do they ever have a visitor named Kirk?"

"Kirk!" she echoed.  "Oh, yes, I recollect, 'e used to often call, but
of late 'e 'asn't been."  And she described my mysterious neighbour
exactly.

"When did he last call?"  I asked.

"Oh, I should say it 'ud be quite a month ago.  'E always used to arsk
for the doctor."

"Never for Mr. Langton?"

"Not to my knowledge.  Indeed, one afternoon when 'e called I told 'im
that the doctor was out, but that Mr. Langton was at 'ome; but 'e told
me that 'e wished to see the doctor an' nobody else."

"How long has Doctor Flynn lived there?"  I inquired.

"About nine months."

"Does he have many callers?"

"No; they all go round to 'is consulting room in 'Arley Street, I
believe."

"All except Kirk."

"Yes, Mr. Kirk used to call at all hours, and they used to sit together
arf through the night sometimes--after Mr. Langton 'ad gone to bed.
'E's never up very late, 'e ain't."

And then, after a few more questions, I allowed the cockney girl to
return to the house, first, however, impressing upon her the need for
secrecy, and adding another five shillings to that I had already given
her.

Half an hour later I saw the front door open, and Flynn, in dark
overcoat and hard felt hat, ran down the steps and turned towards Oxford
Street.

Soon I was at his heels.  He presently turned into Wigmore Street,
crossed Cavendish Square, and continued through Mortimer Street into
Wells Street, quite unconscious of being followed.  He walked with an
air of preoccupation, twice stopping to light his cigarette.

Now that he was under my observation I did not intend that he should
escape me.  Besides, there was nothing suspicious about me, for I was
merely a plain motor-mechanic, such as is seen about the London streets
in dozens at all hours.

Continuing down Wardour Street he came into Coventry Street, where he
ascended the carpeted stairs to a saloon well known to a certain class
of the habitues of the West End.  In my mechanic's clothes I knew that
the uniformed janitor at the bottom of the stairs would direct me to the
public bar, therefore I was compelled to remain outside and await the
doctor's exit.

The place was evidently crowded, as it usually is, for it is one of the
recognised nocturnal rendezvous in the neighbourhood of Leicester
Square.

I crossed the road and stood near the entrance to the Motor Club, of
which I was a member.  Many men I knew passed and repassed within its
swing doors, but none recognised me.  Therefore I was quite satisfied
that, with my dirty face, Doctor Flynn would not easily identify me.

At last he came forth, and alone.

I saw by his hesitation on the kerb that he was disappointed.  Someone
he had expected had not turned up, and he was now undecided in which
direction to walk.

It was then about half-past ten, the quietest hour of the evening in
that neighbourhood, yet the illuminated signs lent an air of gaiety to
that scene so typical of London as the middle-class know it.

Having lit a cigarette the doctor strolled down the Haymarket, and
turning up Charles Street, passed the "Junior," crossed St. James's
Square, where he entered the "Sports," made inquiry for someone, but
found the person was not in.  Then, continuing his way--while I walked
at a respectable distance behind--he turned into Duke Street, where at a
door about half-way up he paused and tugged at a bell.

I took careful note of that door, one with a semi-circular fanlight
above and a painted number, and then turned quickly on my heel to avoid
passing him as he stood in my way upon the pavement.

He was admitted and the door was closed.  Then I passed the house, and
saw that it was a good-sized one, probably let in sets of chambers, as
are many of the houses in that vicinity.

I walked on to Jermyn Street and stood at the corner, lighting my pipe.
A white-faced man passed--a wretched, decrepit old fellow whose hollow
cough told its own tale, and who offered me matches.  I bought a box,
and began to chat with him.  All loafers are fond of a gossip, and I did
this in order not to appear to the watchful constable, who was trying
the locked doors of shops in the vicinity, that I was loitering.  A
well-dressed man may linger as long as he likes, but one who appears as
a mechanic, or as a shabby idler, is very soon moved on unless he, in
turn, is, a "nark," or police-informer.

The old man related to me a pitiable story of misfortune which might or
might not be true, but it served to while away the time, while I, on my
part, kept an ever-watchful vigilance upon the door just down the
street.

I must have been there nearly an hour, for the traffic at the end of the
street in Piccadilly had awakened, and every moment the lights of
hansoms and taxis were flitting past.  The theatres were just over, and
the pleasure-seekers were already westward bound.

At length, just as I had grown inexpressibly weary, the door I was
watching reopened, and from it emerged Flynn, accompanied by a man in
evening dress with a white muffler around his neck and wearing a
crush-hat--a man whom, in an instant, I recognised as Leonard Langton.

He blew a whistle for a taxi; but, seeing their intention was to drive
away, I sped along into Piccadilly, and, finding one, gave the man swift
instructions to wait until they entered a conveyance, and then to follow
them.

The driver, noticing my clothes, looked askance at me, but I added:

"They owe me some money for work done on a car, and I mean to see where
they go."

There is a clannishness about motor-men, therefore the instant I had
told my story he declared himself ready to assist me.

And as I sat back in the cab Langton and his friend, who had now gained
Piccadilly, passed in search of a cab.

In a few moments they found one, and soon we had turned the corner of
St. James's Street, and were running down to Pall Mall, where we turned
to the left, and after a sharp drive, swung into the station yard at
Charing Cross.

Here the pair alighted, and, watching, I saw them stroll upon the
arrival platform where, according to the chalked figures on the board,
the boat-train from the Continent, already over an hour late, was now
expected.

The usual crowd was waiting there, friends of passengers, porters,
Customs officers, and the women agents of the various female rescue
societies--an expectant crowd which, year in, year out, never differs.

The pair halted in earnest conversation about half-way along the
platform, while I strolled slowly at some distance away, with my eyes
upon them.

Flynn was arguing something, emphasising his words with his hands, while
Langton stood by listening in silence.

Then there was the sudden movement of the porters who had noticed some
signal fall, and looking towards the dark bridge I saw the headlight of
the engine slowly approaching.

The doctor raised his finger to his friend, an action expressive of an
injunction of silence.

Whom were they expecting to arrive?

With bated breath I stood motionless, watching in eager wonder.

From the arrival, whoever it might be, these men intended to preserve
some secret.

CHAPTER TWENTY ONE.

I MAKE A BOLD MOVE.

For a moment I lost the two men in the excited crowd of alighting
passengers, but when I gained another sight of them, my heart stood
still.

Talking with the pair was a well set-up, alert man whose back was turned
to me--a man in a soft grey felt hat and heavy travelling coat with
beaver collar.  Both men were speaking quickly, eagerly, telling the
new-comer something of an urgent nature, being hustled at the same time
by the bustling passengers eager to claim their luggage from the Customs
barriers, and get away.

I moved a little distance along, recognising in the man just returned
from the Continent the grey, thin, sinister face of Kershaw Kirk.

My first impulse was to rush forward and demand of him the truth;
indeed, to charge him with a secret crime, and to insist on knowing the
whereabouts of my beloved Mabel.  But it struck me at that instant that
the two men who had met him had agreed between themselves upon a course
of secrecy, and that they were therefore misleading him.  Had not
Ethelwynn already told me of Langton's suspicion of this man, who was to
me and mine such a mystery?

Therefore I held back for the moment, awaiting my opportunity.

Standing beyond the barrier where the baggage was being sorted, ready
for the Customs examinations, I watched the trio from my unseen point of
vantage.  I doubt that either would have recognised me in those greasy
mechanic's clothes of mine.

Within myself I felt a sense of complete satisfaction.  Kirk had
returned to England, and was therefore now within the jurisdiction of
the law, however much he might pretend to be immune from its penalties.

What Flynn was saying evidently caused him to hesitate.  He was
thoughtful for a single moment, but next second shrugged his shoulders,
with a gesture of disregard.

A taxi drew up close to where I stood, and I engaged him, telling him to
wait.  To my satisfaction I saw it was the same driver who had brought
me along from Piccadilly.

Then, as I watched, I saw something which caused me to reflect.  A
porter, quickly recognising Kirk, took from him his baggage ticket and
foraged out a big, battered kit-bag which had been placed upon the bench
ready for the argus eye of his Majesty's Customs.  The porter uttered a
word to the revenue officer and pointed to the bag, whereupon the
officer chalked it without opening it.

Kirk's name, it seemed, was as a _laisser-passer_ at Charing Cross.  Who
was this man that his belongings should be exempt from Customs'
examination?

He looked much travel-worn, yet presented the same active, alert figure
that I had seen passing and repassing before my house.  No longer shabby
or down-at-heel, however, he had, on the contrary, looked beaming and
prosperous until those two men had imparted the information which had,
in an instant, caused his brow to cloud, and he became serious and
pensive.

The old brown kit-bag bearing many hotel labels was placed upon a taxi,
which the three men entered and drove away, I following close upon them.

Half-way up St. James's Street they pulled up at Boodle's, where all
three entered.  Which of the three, I wondered, was a member of that
most exclusive and old-fashioned institution?

They remained there nearly half an hour, when Kirk emerged, and, bidding
good night to his friends at the kerb, re-entered the taxi and drove to
Whitehall Court, that large block of flats which overlooks the
embankment close to Northumberland Avenue.  Here the liveried porter
saluted him respectfully and carried his bag to the lift, up which a few
minutes later he disappeared.

In my mechanic's attire I was now placed at a great disadvantage.  Any
inquiry I might make of the gorgeous attendant would, I knew, only
arouse suspicion, but a thought instantly occurred to me.  The friendly
driver of my taxi, believing that I, a motor man, had been swindled,
might perhaps help me.  We had pulled up at the corner where, in a few
brief sentences, I now explained to him that I was anxious to know
whether Kirk resided there in his own name.

"I'll inquire for you, mate, if you like," declared the taxi-driver
cheerily.  "You just wait here."

And while I mounted guard over his cab, the red-moustached driver went
along to the entrance to the flats.  I saw him in conversation with the
lift man, and when presently he returned he said:

"The gentleman just gone in is Mr. Seymour, who lives on the third
floor.  He's abroad very often, it seems, and is only just back.  He's
lived there a couple of years."

Now I recollected that Kirk, when we had sat together that first night
in Bedford Park, had told me that he possessed another home, and I had
now run him to earth.

Whitehall Court is an expensive place of residence.  Apartments there
seemed far beyond his income as he appeared when he passed my house,
shabby, broken-down, and often hungry-looking.

I gave my friend the taxi-man half a crown beyond his legal fare and
dismissed him, afterwards walking as far as the entrance to the National
Liberal Club, trying to decide how next to act.

To face the fellow boldly and unflinchingly was, I recognised, the only
way in which to gain the knowledge I sought.  Yet in the garb of a
mechanic, was I not much handicapped?  Nevertheless, I walked back, and,
finding the hall porter, gave my name as Flynn, and asked to see Mr.
Seymour upon important business.

After a wait of nearly ten minutes a man in uniform came and ushered me
up in the lift to the third floor, where, having traversed a long,
thickly-carpeted corridor, he opened a door and allowed me to pass
across the small well-furnished hall of the flat into a sitting-room,
where I found myself again face to face with my mysterious neighbour.

He started at sight of me, but so perfect an actor was he that in a
second he had recovered himself, and inquired with affected
friendliness:

"Why, my dear Holford, why in the name of Fate did you send up your name
as Flynn?"

"Because I wished to see you, Mr. Kirk," was my hard response, for we
were now alone together in that cosy, sumptuously-furnished
sitting-room, through the windows of which I could see the dark flowing
Thames and the row of gleaming lights on the Surrey shore beyond.  "I
knew," I added, "that if I had sent up my own name I should not be
received."

"Why?" he asked, opening his eyes widely.  "I don't follow you.  Surely
you have acted as a good friend to me, therefore why shouldn't I receive
you?  I've only this very moment returned from abroad.  Who told you I
was back again?"

"No one.  I obtained the knowledge for myself," I said, "and I have come
here, Mr. Kirk, for several reasons, the chief being to ask you a simple
and pointed question: who killed Professor Greer?"

"My dear sir," he exclaimed, looking straight at me with unwavering
gaze, a slight change, however, showing in his thin, grey countenance,
"that is the very problem that I myself am trying to solve--but in
vain."

"An impostor is passing himself off as Greer," I declared.

"Is he?" asked Kirk quietly.  "I was not aware of that."

"Not aware of it!"  I cried in angry dismay.  "Do you actually deny,
then, that you are acquainted with this man who has taken the
personality and honours of Professor Greer upon himself in order to
preserve the secret of the unfortunate scientist's death?"

"I deny being aware of any person attempting to pass himself off as
Greer," was my mysterious neighbour's bold and unflinching reply.

Had I not sent that telegram from Broadstairs and signed it Kirk, and
had not its receipt caused the false Professor quickly to change his
quarters?  Kirk's reply staggered me.

"Look here," I exclaimed again, raising my voice in anger at this open
denial of what I knew to be the truth, "on the night of your escape from
Sussex Place, the house was searched, and I found evidences of all
traces of the crime having been effaced in the furnace of the
laboratory."

"I know," was his simple response.  "I was quite well aware of that.  I
hope, however, Holford, that you have kept your promise and kept a still
tongue."

"To a certain extent, yes."

"You told Langton nothing, I trust?" he asked anxiously.

"Why are you in such mortal fear of Langton?"  I demanded hotly, halting
before him as he stood on the hearthrug coolly surveying me, with his
back to the fire.

"My dear fellow," he answered, "pray calm yourself.  Have a drink, and
let's discuss this matter amicably from a purely business-like
standpoint.  Surely when I invoked your aid I did not commit a grave
error of judgment?  You have been judicious throughout, I hope?  You
have not forgotten the great issues which I explained depended upon your
silence?"

"My silence you shall command no longer, Mr. Kirk!"  I cried, suddenly
interrupting him.  "I've been silent far too long."

"Ah!" he remarked, still unruffled.  "I see.  Well, your attitude is
quite justifiable, my dear sir--quite.  You have lost your wife, I
understand."

"Yes," I said, advancing towards him a couple of paces in a manner which
I now believe must have appeared threatening.  "And you know more about
the trap into which my poor wife has been led than anybody else.  That
is why I'm here to-night--to compel you to speak--you crafty old cur!"

"My dear Holford, why--what's the matter?" he asked, even then quite
unperturbed.  "Now if I did not know you so well I might easily be
annoyed, but I'm not.  No doubt the loss of Mrs. Holford has seriously
upset you."  And the fellow actually smiled at this.

I grew furious.  The mysterious man's eyes gleamed with a triumphant
light, and his pale lips parted, revealing his pointed teeth.

"You make pretence of ignorance!"  I cried.  "You think that I believe
you when you say you know nothing of where she is, but--"

"I assure you, Holford, that these suspicions of myself are entirely
groundless.  I have no knowledge whatever of the lady.  I have seen her
once or twice at her dining-room window, it is true."

"And yet I've been out to Florence, to the Grand Bretagne, where I was
informed that you had been in her company!" was my hasty reply.

"I can't help what cock-and-bull story you've been told by an Italian
hotel-keeper.  They are notorious for their untruths, as you would
discover if you travelled as much up and down Italy as I do," he said
with an evil grin.  "I can only tell you, once and for all, that I have
no knowledge whatever of your wife's present whereabouts."

"Then who has?"

"How can I tell, my dear sir?  You ask me a riddle.  On my arrival at
Charing Cross an hour ago one of my friends who met me told me of Mrs.
Holford's sudden journey abroad and her disappearance into space.  The
story set me wondering as to the motive of the plot--for plot it
undoubtedly must be.  Mrs. Holford and yourself, I am told, are devoted
to each other.  There is no reason for her leaving you, is there?"

"Understand this, Kirk," I said.  "I've been fooled quite long enough.
As my wife has been enticed away, and is held aloof in some unknown
place, I give you full and ample warning of my intention.  It is to go
straight to the police, and while invoking their aid to try and find
her, at the same time to tell them the whole story of the affair at
Sussex Place, just as I know it."

The man half turned from me and bit his thin under-lip.  His grey,
furrowed countenance had become even more grey and more determined,
while in his eyes I saw an evil glitter.

"Ah!  You've been trying to seek solution of the mystery for yourself.
I know all about that!"  He laughed hollowly.  "But, as you are aware of
only half the tangled skein of mysterious facts, it is hardly likely
that you'll succeed, do you think?  Did I not tell you to remain silent
and inactive?  Instead of that, you've been chattering and trying to act
the part of amateur detective.  It was fatal.  Because of that--and for
that reason alone--the misfortune has been placed upon you."

"What misfortune?"

"The loss of your wife.  It has occupied your mind in another way, just
as it was intended by your enemies it should do."

"And yours is the master mind, Mr. Kirk, which has planned this subtle
revenge," I exclaimed, my eager hands clenched in frantic desperation.
"Because I disobeyed your extraordinary injunctions Mabel has been taken
from me.  You may as well admit the whole truth now at once."

"I admit nothing," he answered, drawing himself up defiantly.

"Then, by Heaven, I'll force you to speak--to tell me where she is!"  I
shouted, as I raised my hands with a sudden movement.  And then, before
he could ward me off, my fingers closed upon his hard, bony throat.

I was desperate.  Nay, in the presence of that sphinx-like, taciturn
adventurer whom I now knew to be my enemy, I was mad.

Yes, mad, or surely I would never have dared to lay hands upon him.

CHAPTER TWENTY TWO.

DEFIANCE PROVES DEFENCE.

I had, I confess, allowed my anger to rise above my gorge.  That action
of mine in attacking Kirk was both ill-timed and very injudicious, for
in an instant--before even those frantic words had left my lips--I found
myself looking down the ugly black barrel of a big Browning revolver,
that most effective and deadly of all man-killing weapons.

"Kindly release me, Holford," he said, rather hoarsely and with some
difficulty, as my muscular fingers had closed upon his scraggy throat.
"Come, this is all very foolish!  Let me go!  I have no desire to harm
you," he added, quite calmly.

"Then tell me where I can find my wife," I repeated.

"I would--if I could."

"Tell me who can!"  I demanded fiercely, my fingers still closed upon
his throat, so that he breathed only with great difficulty.

"Give me time--time to make--inquiry!" he gasped.  "I've only just
returned, and am in ignorance of a great deal of what has transpired."

"Upon your own admission, Mabel has fallen a victim of a plot merely
because I became too active and too inquisitive.  You feared lest I
might discover something."

"I have admitted nothing, my dear sir!" he cried.  "One day you will
withdraw all these malicious words--mark me," he added, in a hard voice,
lowering his weapon and replacing it in his hip-pocket as I released my
convulsive grip.

"I've lost my wife, Mr. Kirk, and you know where she is," I said.

"In that you are quite mistaken," he declared.  "As I've already
explained, I've not yet had opportunity for making inquiry.  I
believed," he added in reproach, "that you would assist me in this
strange affair concerning Professor Greer.  Yet my confidence in you,
Holford, has been sadly misplaced.  Recall for one moment what I told
you--of the seriousness of what was at stake, and of the absolute
necessity for complete secrecy.  Yet to-night you threaten to bungle the
whole affair by going to the police."

"I've lost my wife!"  I interrupted.  "She's the victim of some plot or
other, and it is to find her that I intend to invoke the aid of Scotland
Yard."

"Well, by adopting that course, you would not find her--but you'd lose
her," was the old fellow's brief response.

"Antonio told me the very same thing when we met in Rome!"  I exclaimed.
"Your threat shows me that you are in league in this conspiracy of
silence."

Kershaw Kirk burst out laughing, as though he considered my anger a huge
joke.  It annoyed me that he did not take me seriously, and that he
regarded the loss of Mabel so lightly.

"Look here, Mr. Holford," he said at last, looking straight into my
face.  "It's plain that you suspect me of being the assassin of
Professor Greer.  That being so, I've nothing more to say.  Yet I would
ask you to regard the present situation both logically and calmly.  Do
you for one moment suppose that were I guilty I would have taken you to
Sussex Place and explained the whole affair in detail?  Is it, indeed,
to be supposed that I would place myself so entirely and completely in
the hands of a stranger?"

I shook my head dubiously.

"Well," he went on, "I repeat to you now all that I told you that night,
and assert that all I told you was the truth."

"But how do you account for Ethelwynn being still alive?"  I interrupted
quickly.

"There is an explanation of that," he declared; "one that you will
probably be told very shortly.  Fortunately, the poor girl was not dead,
though I confess I was entirely deceived by the symptoms.  You will
remember that the mirror remained unclouded by her breath?"

"I remember every incident, alas! only too vividly," was my slow,
distinct reply.  "But," I asked very pointedly, "pray tell me, Mr. Kirk,
what was your object in calling upon me and inducing me to go to Sussex
Place?"

He thrust his hands into his trousers pockets and smiled.

"An ulterior one--as you may imagine.  But one which was as much in your
interests as in ours."

"Ours!"  I echoed.  "You mean you and your accomplices?"

"Call them so, if you wish," he laughed.  "I, unfortunately, am not in a
position to enlighten you upon the actual reason I invoked your aid."

"And your action has only brought upon me a great misfortune--bitter
despair, and the loss of the woman I loved!"  I cried, dismayed.

"Ah!" he said.  "You judge me a little too hastily, Mr. Holford.  It is
your failing, Mr. Holford, that you are given to rushing to premature
conclusions.  That is always fatal in any delicate negotiation.  When
you've had my experience--that of a traveller and thorough-going
cosmopolitan--you will learn how to repress your own opinions until they
are fully and entirely corroborated."

I looked into the grey face of the clever adventurer, and there saw
craft, cunning, and an ingenuity that was superhuman.  A look was in his
eyes such as I had never before seen in those of any human being.

"But I am in search of my wife!"  I cried frantically.  "I am in no mood
to hear this philosophy of yours."

"Well--how do you know she is not here--in London?" he asked, waving his
thin hand towards the window where showed the glimmering lights of the
Thames bank.

To the right, where I stood, I could see the gleam of electric light
from the summit of Big Ben, showing that the House, which had assembled
only a few days before, was sitting late after the Christmas recess.

"I suppose you wish to mislead me into the idea that she is back again
in London, hiding from me, eh?"  I exclaimed resentfully.  "No, Mr.
Kirk, I tell you plainly that I've had enough of this tragic comedy of
yours, I've watched you this evening with your precious friends, Flynn
and Langton."

"And, pray, why should I not possess friends?" he asked, looking at me
with some surprise.

"To me Langton denied all knowledge of you."

"Well--and am I to be blamed for Langton's pretended ignorance?"

"No; but it shows me that you are not dealing with me in a
straightforward manner!"  I declared, without mincing words.

But the strange old fellow only laughed.  "My dear sir," he said a few
moments afterwards, "I can quite understand your distrust of me,
therefore it is as well that I hesitated to place a further confidence
in you.  You might have betrayed it."

"Betrayed it!"  I echoed angrily.  "Have you not betrayed me?  Is it not
due to you, and you alone, that my wife is missing?"

"That I emphatically deny, my dear sir," he replied, still quite
unperturbed.  "But why let us discuss it?  Any denial of mine you'll
regard as false.  It's a great pity that my judgment led me to seek your
aid.  Had you carried out my request and refrained from prying into
matters which did not concern you, you might have found it to your
distinct advantage."

"You mean that I should have profited pecuniarily by concealing the fact
that Professor Greer is dead and that an impostor has assumed his
identity?  You intended that I also should be an accomplice of the
assassin!"

"No--not exactly," he replied with an evil, triumphant grin.  "But,
really, my dear sir," he added, "I've had a very long journey, and I'm
tired.  Is it any use prolonging this argument?"

"Not unless you wish!"  I snapped.  "I have given you full warning of my
intention to reveal the whole affair to the police."

"Ah!  Then that will be very unfortunate--for you," replied the queer
old man; "and for your wife most of all."

"Yes, I know.  You intend to bring disaster upon me and upon her if I
dare to go to Scotland Yard!"  I cried.

In my ignorance of the truth I believed my threats would be of avail.
Ah, had I but known the actual facts, how differently would I have
acted!  But surely that enigma was one that was beyond human power to
elucidate.  Upon every hand I found complications.  Plot lay within
plot--all directed against myself and against poor innocent Mabel, who
had flown to me on receipt of what she had believed to be my urgent
telegram.

"My intentions, Mr. Holford, entirely depend upon your actions," said
Kirk, very plainly.  "If you are foolish--well, then I cannot guarantee
the safety of your wife.  My advice to you, however, is to recall all I
told you, believe in the truth of my statements, and act with slow
discretion."

"But my wife?"  I cried.  "I must--I will save her.  She is in peril, I
am sure of that!"

"She may be in grave peril if you go to the police," he said
enigmatically; "and, believe me, they cannot assist us in the least to
discover who killed Professor Greer."

"Why?"

Kirk hesitated.  In that pause I scented an intention further to prevent
me from speaking.

"Well, regard the matter calmly and without prejudice," he said at last.
"As a matter of fact, what evidence is there that the Professor is
dead?"

"Evidence!"  I cried.  "Why, did not you and I see him dead?  Did not
his daughter stand before his lifeless body?"

"Ah, she would never tell what she saw!" he said, with a mysterious
smile.

"Why not?"  I asked, much surprised at his remark.

But my mysterious neighbour only shrugged his shoulders vaguely,
answering:

"There is a reason why she will never admit his death--a strong reason."

"Well," I said, "I recovered from the ashes of the furnace certain
remains--coat buttons and other scraps of clothing."

"And you think they would be accepted as evidence that Professor Greer
was done to death?" he laughed.  "You are evidently unaware of the great
caution exercised by the Criminal Investigation Department in accepting
any evidence such as that which you could furnish.  No," he added, "only
Antonio and Ethelwynn were the actual witnesses, in addition to
ourselves, of the Professor's tragic end.  And as they refuse to admit
that he is dead, any information you may lodge at Scotland Yard must
only reflect upon yourself and bring greater peril upon Mrs. Holford.  I
simply tell you the truth--believe me, or believe me not."

"Well," I exclaimed, "I disbelieve you, Mr. Kirk."

"Then I wish you good evening!" he exclaimed abruptly.  "Act as you
think proper!" he added defiantly, as, turning from me in disregard he
walked to his large writing-table, where he took up some letters, at the
same time singing, with that careless cosmopolitan air of his, Lucien
Fugere's popular _chanson_, which at the moment one heard everywhere in
the streets of Paris.

"Then that's your last word, eh, Mr. Kirk?"

I asked when he had concluded the verse.

"It is," he replied determinedly.  "If you must act as a fool, then I
can't assist you further.  Good night!"  And he sat down and busied
himself with his accumulated correspondence.

I now realised that he was utterly defiant, and thoughts of my loss of
Mabel caused my blood to boil within me.  His light, careless manner
irritated me beyond measure.

"Very well," I cried.  "Good night, Mr. Kirk!"  And turning swiftly upon
my heel, I left the room and found my way down the great staircase and
out into Whitehall.

Too late at that hour to call at New Scotland Yard, close by, I hailed a
hansom and drove straight home, almost beside myself with rage at the
calm, unruffled, defiant attitude with which the adventurer had met me.

Next morning, after writing some letters, I went round to the garage,
where I found Pelham, somewhat excited.

"This morning, when I arrived at eight o'clock," he said.  "I found
awaiting me a rather shabbily-dressed old man who said he wanted to see
an Eckhardt tyre.  Recollecting my previous experiences of people who've
come in to handle them, I told him that if he wished to buy one I could
sell him one, but I hadn't time to waste on sightseers.  Whereupon the
old fellow promptly paid for a cover before seeing it, and took it away
on a cab which he had waiting."

"Well?"  I asked, rather, surprised.  "And who was he?"

"That's the curious point.  He was an old chap I've seen about the
neighbourhood many times--thin, rather shabby and disreputable, grey
hair and moustache--lives in your road, I think.  Drake says you know
him."

"Kershaw Kirk!"  I gasped.

"Yes; that's the name Drake said before he went out with the `sixty,'"
replied my manager.

"What does he want with a tyre when he hasn't got a car?"

I stood in silence.  What, indeed, did that man want with one of the new
tyres?  Had he merely come down there to have further words with me, or
did he require a cover for some specific purpose?

My mind, however, was made up.  I had resolved to go to New Scotland
Yard, and, even though tardily, to place the whole of the facts before
the Criminal Investigation Department.  Therefore I got out the
"forty-eight" and drove along the Hammersmith Road and Knightsbridge,
across St. James's Park, and through Storey's Gate to Whitehall.  I
alighted in the big courtyard of the police headquarters, where a number
of motor-'buses were drawn up for inspection, and entered the large
stone hall, when a constable came forward to inquire my business.

I handed him my card, explaining that I wished to see one of the
detective inspectors upon a confidential matter, and was shown upstairs
and along a wide corridor to a bare waiting-room.

For some ten minutes I remained there, when the door opened, and I found
myself face to face with a middle-aged, pleasant-faced man, who was one
of the most noted and experienced officers of the department.

For a moment I held my breath.  I recollected all the threats that had
been made of Mabel's peril if I dared to speak the truth.

The detective-inspector closed the door behind him, and, wishing me a
polite "Good morning," inquired my business.

I told him.  Yes; I blurted forth the truth, and made a clean breast of
the whole matter.

But the instant I had done so I bitterly repented it.

I realised something which I had not before recognised.

I saw that, even though my dear wife were missing and in peril, I was a
fool--an utter idiot--for having dared to breathe a word.

My injudicious statement had only rendered the enigma still more
complicated than hitherto.

CHAPTER TWENTY THREE.

THE UNEXPECTED HAPPENS.

The shrewd officer seated at the table with me, a pen in his hand, heard
my narrative to the end, now and then making brief memoranda.

Presently he exclaimed:

"Would you kindly excuse me?  I'd like another gentleman to hear this
story."  And he rose and left.

A few minutes later he returned with a rather taller, clean-shaven man,
slightly younger, who had on a dark overcoat and carried a silk hat in
his hand.

"This is Mr. Holford," said the first officer, introducing me.  "He's
just told me a very remarkable story, which I'd like you to hear for a
moment."

Then, turning to me, he asked me to repeat briefly what I had alleged.

The new-comer, seating himself, listened attentively to every word which
fell from my lips.  I noticed that he exchanged curious glances with his
brother officer.

"Your main reason, then, for telling us this story is in order to compel
those responsible for your wife's absence to reveal her whereabouts, I
take it?" asked the younger man.

"Exactly."

"The false telegram was dispatched from Turin, eh?"

"Yes.  Cannot you communicate with the Italian police concerning it?"

"And pray what good would result?" he queried.  "After long delay we
might perchance get the original of the telegram, but I don't see that
that would assist us very far.  When people send bogus messages they
generally disguise their handwriting."

"Well, I leave it to you to take what steps you like to assist me," I
said.  "My sole object is to find my lost wife."

"Naturally, my dear sir," observed the officer.  "We'll first take down
your statement in writing."  And then the man I had first seen wrote at
my dictation a brief summary of the mysterious death of Professor Greer
and its attendant complications and my suspicion of Kershaw Kirk.

"Well, we'll place this before the Commissioner to-day.  Perhaps you'll
call to-morrow; say about this time.  We will then let you know our
opinion and our intentions."

With that I was compelled to be satisfied, and I left the waiting-room
full of hope that by that bold move of mine I might gain knowledge of
the whereabouts of my well-beloved.

How I existed throughout that day I cannot tell.  I tried to attend to
my business, but in vain.  I was wondering what action was being taken
by my sinister-faced neighbour who lived in Whitehall Court under
another name, and who seemed to possess a dual personality.

At last the hour came when again I turned the car into Scotland Yard,
and once more was ushered upstairs into that bare waiting-room wherein
so many stories of crime are related.

Presently, after a lengthy wait, the two officers entered together and
greeted me.

"Well," commenced the elder of the pair with some slight hesitation,
"we've placed your statement before the Commissioner, Mr. Holford, and
he has very carefully considered it.  He has, however, decided that it
is not a matter for our department."

"What?"  I gasped.  "A man can be foully done to death here in London,
and yet the police refuse to believe the story of an honest man--a man
who is a witness!"

"We do not doubt you in the least degree, Mr. Holford," the other
assured me, speaking very quietly.

"But you do!"  I exclaimed in quick anger.  "I've told you that a crime
has been perpetrated."

"My dear sir," said the officer, "we get many startling stories told
here almost hourly, and if we inquired into the truth of them all, why,
we'd require a department as big as the whole of Whitehall."

"What I told you yesterday is so strange and extraordinary that you
believe I'm a madman," I said.  "I see it in your faces."

"Excuse me, but that is not the point," he protested.  "We are only
officers, Mr. Holford.  We are not the commander.  The chief has given
his decision, and we are compelled to obey, however much we may regret
our inaction."

"So you refuse your aid in assisting me to find my wife?"

"No.  If we can help you to discover Mrs. Holford, we willingly will.
Perhaps you'll kindly give us her description, and we'll at once
circulate it through all our channels, both here and abroad.  But,"
added the man, "I must first tell you that we can hold out very little
hope.  The number of missing wives reported to us, both here at
headquarters and at the various local stations in the metropolitan area,
is sometimes dozens in a day.  Most of the ladies have, we find on
inquiry, gone away of their own accord."

"But this case is different.  My wife has not!"  I asserted.  "She has
been enticed away by a telegram purporting to come from me."

"And that's really nothing unusual.  We have heard of ladies arranging
with other people to send urgent messages in the names of their
husbands.  It is an easy way of escape sometimes."  And he smiled rather
grimly.

"Then, to put it plainly, I've nothing to hope for from you?"  I
snapped.

"Very little, I fear, sir."

"And this is our police system which was only recently so highly
commended by the Royal Commission of Inquiry!"  I blurted forth.  "It's
a scandal!"

"It is not for us to make any comment, my dear Mr. Holford," said the
elder of the two officers.  "The Commissioner himself decides what
action we take upon information we may receive.  I dare say," he added,
"our decision in this case does appear to you somewhat strange, but--
well, I may as well point out that there is a special feature in it
which does not appear to you--an outsider."

"What special feature can there be, pray?  A well-known man has been
assassinated.  Surely, therefore, it is the duty of the police to stir
themselves and make every inquiry!"

"We have only your statement for that.  As far as we or the public are
aware, Professor Greer is travelling somewhere on the Continent."

"But, if you disbelieve me, go to Kershaw Kirk, in Whitehall Court, or
to the Professor's daughter down at Broadstairs, or to Pietro Merli, who
keeps a newsagent's in the Euston Road.  Each of these persons knows the
truth, and would speak--if compelled."

"The Commissioner has had all those names before him, but in face of
that he has decided not to enter into this matter.  His decision," said
the officer, "is irrevocable."

"Then our police system is a perfect farce!"  I cried.  "No wonder,
indeed, we have in London a host of undiscovered crimes!  The man Kirk
laughed at you here as blunderers!"  I added.

But the pair only exchanged glances and grinned, causing me increased
anger.

"In any other city but London the police would, upon my information, at
once institute inquiry!"  I declared.  "I'm a tax-payer, and am entitled
to assistance and protection."

"We have already offered to assist you to discover the whereabouts of
Mrs. Holford," the elder man pointed out politely.

"Then inquire of this man Kirk, or Seymour, as he calls himself, in
Whitehall Court," I said.  "He can tell you where she is--if he
chooses."

"You suspect him of having a hand in her disappearance?  Why?" inquired
the other detective officer.

I related clearly and succinctly the facts upon which my belief was
based and of the description given of my wife's companion by the
hotel-manager in Florence.

The officer slowly shook his head.

"That's scarcely conclusive, is it?  The description is but a vague one,
after all."

"Well," I said bitterly as I rose, "if you refuse to assist me, I must,
I suppose, seek redress elsewhere.  May I see the Commissioner myself?"

"You can make formal application, if you like.  But I don't expect he
will see you.  He has already fully considered the matter."  And that
was all the satisfaction accorded me.

"Then I'll do something!"  I cried.  "I'll get a question asked in the
House.  It's a scandal that, with Professor Greer killed in his own
home, you refuse to bestir yourselves.  After all, it seems quite true,
as has been recently alleged, that the police are nowadays so fully
occupied in regulating the speed of motor-cars that they have no time
for the investigation of crime."

I noticed that at my threat to have a question asked in the House, one
of the officers pulled a rather wry face.  The Metropolitan Police were
not fond, I knew, of questions being put about them.  I chanced to know
rather intimately a member for a country division, though to get the
question put would necessitate my explaining the whole affair.

Yet was not Mabel's liberty--nay, perhaps her very life--at stake?

"You've told us very little regarding this friend of yours, Mr. Kershaw
Kirk, whom you appear to suspect so strongly," the younger of the two
men remarked at last.  "Who is he?"

"An adventurer," I replied quickly.  "I have no doubt whatever upon that
point."

The man pursed his lips dubiously.

"May it not be that you are somewhat prejudiced against him?" he
ventured to suggest.

"No.  He was in the house at the time when the Professor's body was
cremated in his own furnace.  If you went to Sussex Place you would
probably discover some remains among the ashes."

"Do you allege, then, that you were an actual witness of the cremation?"
asked the officer.

"No; I found him in the house."

"And, later on, you discovered the furnace alight, eh?"

"Yes."

"Then it is only a surmise on your part, after all, my dear sir,"
remarked the detective, twisting a pen between his fingers as his dark
eyes were fixed upon mine.  "The actual evidence is really _nil_.  That
is just the view taken by the Commissioner."

"But my wife is in the hands of the assassins," I cried.  "You can't
deny that!"

"Is there any actual, evidence of it?  None, as far as we can see," he
declared.  "Would it not be natural for your wife, on failing to find
you in Florence, either to wire to her sister at home or to return home
at once?  She did neither, which only goes far to prove that she did not
desire to return to London."

"You suggest that she has purposely left me?"  I cried, staring at the
man in a frenzy of angry resentment.

"I suggest nothing, Mr. Holford.  Pray don't misunderstand me.  I merely
put before you the facts in order to obtain a logical conclusion.  Only
one can be arrived at--she had some motive for not returning to her
home.  If she had, then how are we to find her?  She would, no doubt,
purposely cover her tracks."

"But she was with that man, the man who--"

"And that just bears out my argument," interrupted the detective.

"But may she not have been prevented from sending any message home?"  I
suggested, though that very point he had made had, I confess, been the
one which had continually obsessed me.

Both the detectives shook their heads.

"No," replied the elder of the two.  "We are both agreed, as the
Commissioner also believes, that your wife would not be held a prisoner.
Criminals do not hold women prisoners nowadays, except in works of
fiction.  No," he added, "depend upon it, Mr. Holford, when you discover
the truth, you will find that your wife was acquainted with one or other
of these friends of yours, and that her disappearance was part of a
plan."

The story of the message received by Mabel while I was in Scotland
flashed across my mind.  I recollected all that Gwen had so guardedly
related to me.

But I stirred myself quickly.  No, a thousand times no!  I would never
believe evil of Mabel before I had absolute proof in black and white.
The mystery of her disappearance was as great and inexplicable as the
problem of who killed Professor Greer?

CHAPTER TWENTY FOUR.

TWO MEN CONSULT.

Beside myself with fear and anxiety regarding the woman I loved so well,
I again called that very same evening upon Kirk at Whitehall Court, but
on doing so was informed by the lift-man that he was out.

A suggestion then occurred to me that he might have gone over to his
other abode at Bedford Park, therefore I returned, and at last knocked
at his door.

His sister answered my summons, and saying that her brother was at home,
ushered me into his presence.

I found him in his old velvet jacket seated in his high-backed arm-chair
before a glowing fire, his pet parrot near him; and as I entered he
greeted me coldly, without deigning to shake my hand.

"Well, Holford," he exclaimed, stretching his slippered feet lazily
towards the fire, "so you have, after all, proved a traitor, eh?"

"A traitor?  How?"  I asked, standing near the fireplace and facing him.

"You have been telling some extraordinary stories about me at Scotland
Yard, I hear," he said with a grin.

"Ah!"  I cried.  "Then you are a detective, after all?  My surmise was
right from the first!"

"No," he replied very quietly, "you were quite wrong, my dear sir; I'm
not a detective, neither professional nor amateur, nor have I anything
whatever to do with Scotland Yard.  They may be sad blunderers there,
but they do not accept every cock-and-bull story that may be told them."

"I told them no cock-and-bull story!"  I protested angrily.  "I told
them the actual truth!"

"And that after all the warnings I have given you!" he said in a tone of
bitterest reproach.  "Ah! you are unaware of the extreme gravity of that
act of yours.  You have broken faith with me, Holford, and by doing so,
have, I fear, brought upon me, as upon others, a great calamity."

"But you are so mysterious.  You have never been open and above-board
with me!"  I declared.  "You are full of mystery."

"Did I not tell you on the first evening you sat here with me that I was
a dealer in secrets?" he asked, blowing a cloud of smoke from his cigar.

"No, Holford," went on my mysterious neighbour, very seriously, "you are
like most other men--far too inquisitive.  Had you been able to repress
your curiosity, and at the same time preserve your pledge of secrecy,
matters to-day would have been vastly different, and, acting in concert,
we might have been able to solve this extraordinary enigma of Professor
Greer's death.  But now you've been and made all sorts of wild
statements to the Commissioner of Police.  Well, it has stultified all
my efforts."

He spoke with such an air of injured innocence that I hesitated whether
I had not, after all, somewhat misjudged him.  Yet as I looked into that
grey, crafty face I could not help doubting him.  It was true that he
had taken me into his confidence, but was it not done only for his own
ingenious and devilish purpose?

"My wife is lost," I observed at last.  "It is her loss that has,
perhaps, led me to say more than I would otherwise have done."

"And love for your wife makes you forget your word of honour given to
me, eh?" he asked.  "Your code of honour is distinctly peculiar, Mr.
Holford," he added, with biting sarcasm.  "I, of course, regret that
Mrs. Holford has fallen a victim to the machinations of our enemies, but
surely even that is no excuse for a man to act treacherously towards his
friend."

"That is not the point," I declared.  "You have never satisfied me as to
your motive in taking me to Sussex Place and exhibiting to me the
evidence of the crime."

"Because--well, because, had I done so, you would not have understood.
Some day, perhaps, you will know; and when you learn the truth you will
be even more astounded than you are to-day.  Meanwhile, I can assure you
that you suspect me entirely without cause."

"Then why were you in the house at the time the traces of the crime were
being effaced in the furnace?"  I asked in a hard voice.

He hesitated for a moment, and I thought his bony hand trembled
slightly.

"For reason's of my own," he replied at last.  "You allowed me to
wriggle out of a very tight corner, and I intended to show you my
gratitude, had you given me an opportunity."

"I desire no expression of gratitude, Mr. Kirk," I replied, with
dignified disgust.  "All I require is a statement from you concerning
the whereabouts of my dear wife.  Give me that, and I'm satisfied to
retire from the whole affair altogether."

"Because you have now realised that Scotland Yard refuse their
assistance, eh?" he asked, with an evil grin.  "Are you not now agreed
with me that our much-praised Criminal Investigation Department, with
all its hide-bound rules and its tangle of red tape, is useless?  It is
not the men who are at fault--for some of them are the finest and best
fellows in the whole metropolis--but the system which is radically
wrong."

I was bound, after my experience, to agree with him.  But again I
referred to Mabel, and to the manner in which she had been decoyed from
home.

"You hear that, Joseph?" he exclaimed, turning to his feathered pet, who
had been chatting and screeching as we had been speaking.  "This
gentleman suspects your master, Joseph.  What do you say?"

"You're a fool for your pains!  You're a fool for your pains!" declared
the bird.  "Poor Jo-sef!  Poor Jo-sef wants to go to bed!"

"Be quiet!  You'll go to bed presently," answered the queer, grey
visaged, sphinx-like man, who, turning again towards me, and looking me
straight in the face, once more assured me that I was foolish in my
misapprehension of the truth.

"To me it really does not matter who killed Professor Greer, or who has
usurped his place in the world of science," I said.  "My only aim now is
to recover my lost wife.  Antonio, when I met him in Rome, was anxious
that, in exchange for information concerning her, I should consent to
keep a still tongue as to what had occurred in Sussex Place."

"Rubbish, my dear sir!"--and Kirk laughed heartily.  "What can Antonio
possibly know?  He's as ignorant and innocent of the whole affair as you
are yourself."

"How do you know that, pray?"

"Well, am I not endeavouring to elucidate the mystery?" he asked.

"And you know more than you will tell me?"

I said.

"Perhaps--just a little."

"Yet you desire that I should still trust you implicitly, that I should
give myself into your hands blindly and unreservedly--you, who lead this
dual existence!  In Whitehall Court you are a wealthy man of leisure,
while here you pose as shabby and needy."

"I may be shabby, Mr. Holford, for certain purposes--but needy never!  I
have, I'm thankful to say, quite sufficient for my wants," he exclaimed,
correcting me.  "And as for my dual existence, as you term it, have I
ever endeavoured to conceal it from you?"

"Tell me--once and for all--are you aware of my wife's whereabouts?"  I
demanded in frantic anxiety.  "Can't you see that this suspense is
turning my brain?"

"Yes, it is very unfortunate--and still more unfortunate that I can
afford you no satisfaction.  The fact of Mrs. Holford's prolonged
absence is as great a mystery to me as to yourself."

"Scotland Yard will render me no help," I said in bitter chagrin.

"Probably not--after the amazing story you told them," was his rather
spiteful response.

"What am I to do?"

"Remain patient and watchful," he said.  "Believe in me, and try and
persuade yourself that, after all, I'm not an assassin," he smiled.

I held my breath for a few seconds.  Here was the crux of the whole
matter.  He was still cleverly and ingeniously endeavouring to lead me
into a false sense of security--to make me believe that he was innocent
of all knowledge of that most astounding tragedy in Sussex Place.

Ah! his was indeed a clever ruse.  But my eyes were now opened, so I
only smiled within myself at the futility of his crafty and clever
attempt further to mislead and cheat me.

A man was with my wife, passing himself off as myself--Henry Holford,
motor engineer.  And yet I could look to no one for counsel, advice, or
aid!

Now that the police had refused to inquire into the death of poor Greer,
the attitude of my weird, grey-faced neighbour had become more defiant.
He was full of bitter reproaches, yet at the same time entirely heedless
of my future actions.

Once or twice while speaking to me he turned, as was his habit, to
Joseph the parrot, addressing asides to his pet, causing the bird to
screech noisily, grow excited, and make idiotic responses.

"Mark me, Mr. Holford," he said at length, "you did a most foolish thing
to betray me to Scotland Yard.  In you I'm most disappointed, I assure
you.  My confidence was misplaced."

"I understand you've been to my garage and in my absence purchased an
Eckhardt tyre," I remarked.

"Well?" he said, opening his eyes slightly.  "I only came down to see
you, but when I found you absent I bought a tyre as an excuse."

"And you expect me to believe that, eh?"  I asked, with a dry laugh.

"You can believe it or not believe it, just as you think fit," was his
quick reply.  "I have no use for motor-tyres, not possessing a car."

I grinned in disbelief, recollecting the air of secrecy with which he
had examined the tyre on the first occasion he had called upon me, and
also the effect produced upon him later when I told him of the two other
men who had called to inspect the tyre.

I think I remained with him for nearly an hour.  Then, after he had told
me that his intention was to stay in England, at least for the present,
I left him and walked back to my desolate home, where, Gwen having
retired, I sat for a further hour in my den, deeply thinking.

That Kirk was in some secret way in association with the bogus Professor
was plain.  Was it not, then, more than likely that they would ere long
meet again?  If I kept a wary eye upon him, I might, I saw, discover
something of great interest.

Who could this man be who led a dual existence for no apparent cause;
this man who was narrow-minded and penurious in Bedford Park, yet was
wealthy and open-handed in Whitehall Court?

As I calmly reviewed the whole extraordinary situation I saw that, in
turn, I mistrusted the whole of the actors in that bewildering drama.
Ethelwynn, the calm, sweet, clear-eyed girl, so content in her great
love for Leonard Langton, though she had actually witnessed her father
lying dead and cold, yet now refused to presume his death!  Why?  Doctor
Flynn I disliked instinctively; Langton was evidently playing a double
game, having denied all knowledge of Kirk, whereas the latter was his
friend; Antonio and Pietro were away; while Kirk himself, silent and
cunning, was pretending a complete ignorance which was only ill-feigned.

And the most important point of all was that not a breath of suspicion
of the Professor's death had yet leaked out to the public.

Thus, utterly bewildered, I again retired to rest.

Early astir next morning, I set watch upon Kirk's movements, assisted by
Dick Drake, my clean-shaven, bullet-headed chauffeur.  A few moments
before eleven he came forth, thinly clad and shabby, as he generally
appeared in Chiswick, and, walking to Ravenscourt Park Station, took a
third-class ticket to Westminster, whence he walked to a rather grimy
house situate in Page Street, a poor neighbourhood lying behind the
Abbey.  There he remained for some time, after which, fearing lest he
should recognise me, I directed Drake to follow him, and returned to the
garage.

At six that evening my man returned, tired and hungry, reporting that
Kirk had gone to a house in Foley Street, Tottenham Court Road, the
number of which he gave me, and after ten minutes there he had eaten his
luncheon at a bar in Oxford Street.  Then he had taken train from
Holborn Viaduct to Shortlands, near Bromley, where he had made a call at
a small villa residence not far from the station.

The door of the house had been opened by a tall, thin man in a dark blue
jersey, who, he said, had the appearance of a foreigner, and Kirk had
stayed inside for nearly two hours.  When at last he came out, the tall
man had walked with him to the station, and bade him adieu on the
platform.

"But," added Drake, "that gentleman's a pretty 'cute one, sir.  He
spotted me."

"H'm, that's unfortunate," I said.  "You were a bit too bold, I fear."

Of course I had told him nothing of the reason why I was watching the
man who had evinced such interest in the Eckhardt tyre.

"I exercised all the caution possible," Drake declared, "but he doubled
back upon me down at Shortlands and thus tricked me.  He didn't say
anything, but only laughed in my face."

The story of the foreigner at the villa at Shortlands struck me as
somewhat remarkable, and I resolved to go there on the morrow and
investigate.  I now held all Kershaw Kirk's movements in suspicion.

Next day I rose with the fixed intention of going at once down to
Shortlands, that district of suburban villadom, but hardly had I risen
from the table where I had breakfasted in silence with Gwen, when
something occurred to turn the tide of events into an entirely different
channel.

Indeed, by that sudden and unexpected occurrence I knew that I had at
last advanced one step towards the knowledge of who killed Professor
Greer behind those locked doors in Sussex Place.

CHAPTER TWENTY FIVE.

A PLOT FAILS.

What actually occurred was this.  I had risen from the table when Annie
entered with a telegram which, on opening, I found to be an urgent
message from Langton, at Broadstairs, begging me to go there at once, as
he had some important information to communicate to me.

From the time-table I found that a fast train left Victoria in an hour,
and full of excitement I bade good-bye to Gwen, promising to wire her
the result of the interview.

Soon after noon I strode down the steep street of the quiet little
watering-place so beloved by Dickens.  On that February day it was very
chilly, and very deserted, but gaining the parade I crossed the
footbridge, and, continuing past the Grand Hotel, went along the top of
the cliffs beyond the town, to where stood the late Professor's seaside
red-brick home.


In the small but pretty drawing-room I was greeted by Ethelwynn and her
lover, who were standing talking near the fire as I entered.  The girl
looked delightfully sweet in a pale blue blouse and dark brown skirt,
her splendid hair dressed in a style that suited her admirably, while
he, on his part, presented the appearance of the typical clean-limbed,
well-bred Englishman.  They were, indeed, a handsome pair.

"It's very good of you, Mr. Holford, to come down so quickly!" the girl
exclaimed, as she took my hand.  "Leonard wants to have a serious chat
with you."

And yet this was the girl who was privy to her father's tragic end.  Was
it possible that her lover also knew the truth?

Langton invited me to a chair, and commenced by haltingly apologising
for bringing me down from London.

"We, however, considered it necessary," he went on; "necessary in the
interests of us all that there should exist a clear and perfect
understanding between us."

"In what manner?"  I asked Langton.

"Well," he said, "it has come to our knowledge that you have been
relating a most extraordinary story regarding Ethelwynn's father.  You
declare that he died under suspicious circumstances."

"Whatever I've said is the truth--the plain and absolute truth," I
declared openly.  "Mr. Kirk introduced me into the house in Sussex
Place, where I saw the poor Professor lying dead in his laboratory."

"Ah!" cried the girl quickly, her manner suddenly changing.  "Then you
are a friend of Kirk's--not of my father?"

"That is so," I admitted.  "And in Kirk's company I saw your father
lying dead through violence."

"And you've dared to put forward this story as an absolute fact!"
Langton cried.  "Do you happen to know who Kershaw Kirk really is?"

"No; I'd very much like to know," I said, full of anxiety.  "Who is he?"

"If you knew, you would, I think, have hesitated before you went to the
police with such a fairy tale as yours."

"It is no fairy tale, Mr. Langton!"  I declared very earnestly.  "I have
with my own eyes seen the Professor lying dead."

"But you forget that my father went to Edinburgh on that night, and
wired me from there next day," the girl pointed out, fixing her splendid
eyes on mine with unwavering gaze.

"I forget no point of the remarkable affair, Miss Greer," I said
quietly.  "As a matter of fact, I followed the man believed to be your
father to Scotland."

"You--you followed him?" gasped Langton, while the girl's cheeks grew
paler.  "Did you see him?  Did you speak with him?"

"No; but I discovered some rather interesting facts which, when the time
arrives, I intend to put forward as proof of a very remarkable
subterfuge."

The pair exchanged meaning glances in silence.  The girl was seated in
an arm-chair opposite to me, near the fire, while Langton stood upon the
hearthrug, with his hands thrust with feigned carelessness into his
pockets.

"The whole affair was no doubt most cleverly planned, thanks to the
ingenuity of Kirk.  The servants were all in ignorance of anything
unusual--all save Antonio, who, as you know, has escaped to the
Continent."

"Escaped!"  The pretty girl laughed uneasily.  "The last I heard of him
was that he was with my father, travelling in Hungary."

"When?"

"Four days ago."

"How can I find them?  What is the Professor's address?"  I asked.

"He has no fixed abode.  My last letter I sent to the Poste Restante in
Buda-Pesth."

In this I saw an intention still to preserve the secret of the
impostor's whereabouts.

"But it was not my intention in asking you down, Mr. Holford, to go into
details of what may, or may not, have happened.  We--that is, Ethelwynn
and myself--know the truth."

"Then tell it to me--relieve this burden of a crime which is oppressing
me?"  I begged.  "Let me know the truth, and let me at least regain my
lost wife."

"Well?  And if we did?" asked Ethelwynn, after a pause.  "We should only
lay ourselves open to an unjust retaliation."

Were not those the words of a woman who possessed some guilty knowledge,
if not herself guilty of parricide?  I saw their frantic desire to close
my mouth, so I let them proceed, smiling within myself at their too
apparent efforts to avoid the revelations which must inevitably result.

"I do not follow your meaning," I said.  "Why should I retaliate, if you
are not responsible for my wife's absence?"

She glanced uneasily across to her lover, who exclaimed:

"As far as I see, the whole thing lies in a nutshell, Mr. Holford.  You
have been misinformed, and have made a ridiculous and quite unfounded
statement concerning Professor Greer--one which seriously reflects upon
his daughter, his household, and his friends.  Therefore--"

"Then does his daughter actually deny having seen him, as I saw him,
lying dead in the laboratory?"  I interrupted.

"I have never seen my father lying dead!" declared the girl in a low,
faltering tone which in itself showed her to be uttering an untruth.
"Your story is entirely unfounded."

"Then let me tell you one thing more, Miss Greer," I said plainly.  "I
myself knelt at your side with Kirk when we found you in the diningroom
lying, as we thought, lifeless.  There was a white mark upon your face.
See!  It has hardly disappeared yet; there are still traces--a slight
red discoloration!"

The girl held her breath at this allegation.  That mark upon her cheek
condemned her.  Even her lover, for a moment, could not reply.

"Ah," he said at last, "the loss of Mrs. Holford has upset you, and
causes you to make all sorts of wild and ridiculous statements, it
seems.  Kirk says they would not listen to you at Scotland Yard--and no
wonder!"

"Then you know Kirk, eh--you who denied all knowledge of him when we
first met!"  I cried.  "It was he who placed the poor Professor's
remains in the furnace in the laboratory, for from the ashes I recovered
various scraps of his clothing which are now in my possession."

"Rubbish, my dear sir!" laughed the young man.  "You don't know Kirk--or
who he is!"

"I know him to be an adventurer who has two places of residence," I
said.

"But an adventurer is not necessarily a scoundrel," Langton replied.
"Many a good-hearted wanderer becomes a cosmopolitan and an adventurer,
but he still retains all the traits and all the honour of a gentleman."

"Not in Kirk's case!"  I cried.

"You've evidently quarrelled with him," remarked Langton.

"I've quarrelled with him in so far as I mean to expose the secret
assassination of Professor Greer and those who, for their own purposes,
are making pretence that the dead man is still alive," I answered
boldly.

"By the latter, I take it, you mean ourselves?" observed the dead man's
daughter.

"I include all who lie, well knowing that the Professor is dead and all
traces of his body have been destroyed," was my meaning response.

"What's this story of yours about Miss Greer presenting an appearance of
death?" asked Langton.  "Tell me--it is the first time I've heard this."
In a few brief sentences I told them of our discovery in the
dining-room, and of the removal of the girl in a cab on that foggy
night.

At my words both looked genuinely puzzled.

"What do you say to that?" asked her lover.

"I know nothing--nothing whatever of it!" she declared.  "I can only
think that Mr. Holford must be dreaming."

"Surely not when, with my own hands, I held a mirror to your lips to
obtain traces of your breath!"  I exclaimed.  "Ask Antonio.  He will
tell you how he and his brother Pietro placed you in a cab at Kirk's
orders."

"At Kirk's orders?" echoed the young man.  "Ask him for yourself," I
said.

They were both full of surprise and anxiety at what I had alleged.

Was it possible that I had been mistaken in Ethelwynn's attitude, and
that she genuinely believed that her father still lived?  But that could
not be, for had she not seen him dead with her own eyes?  No.  The girl,
aided by her lover, was carrying out a cunningly-devised scheme
effectively to seal my lips.

My wife Mabel had, before her disappearance, been in communication with
the impostor whom Ethelwynn had apparently taken under her protection.
This was a point that was most puzzling.  Could this girl and my wife
have been secretly acquainted?  If so, then it was more than probable
that she might have knowledge of Mabel's whereabouts.

Again I referred to the loss of my wife, declaring that if I found her I
would willingly forgo all further investigation into the Professor's
death.

The handsome girl exchanged glances with her lover, glances which showed
me plainly that they were acting in accordance with some premeditated
plan.  Leonard Langton was a sharp, shrewd, far-seeing man, or he would
never have held the appointment of private secretary to Sir Albert
Oppenheim.

"Well, Mr. Holford," he said, "why don't you speak candidly and openly?
You are, I take it, eager to make terms with your enemies, eh?"

"But who are my enemies?"  I cried blankly.  "As far as I'm aware, I've
made none!"

"A man arouses enmity often without intention," was his reply.  "I
cannot, of course, tell who are these enemies of yours, but it is
evident from your statement the other day at Wimpole Street that they
are responsible for your wife's disappearance."

"Well," I said, "you are right.  I am open to make terms if Mabel is
given back at once to me."

"And what are they?" asked Ethelwynn, whose very eagerness condemned
her.

"Pardon me, Miss Greer," I said rather hastily, "but I cannot discern in
what manner my matrimonial affairs can interest you."

"Oh--er--well," she laughed nervously, "of course they don't really--
only your wife's disappearance has struck me as very remarkable."

"No, Miss Greer,"!  Said, "not really so remarkable as it at first
appears.  My own inquisitiveness was the cause of her being enticed
away, so that I might be drawn off the investigation I had undertaken--
the inquiry into who killed Professor Greer."

Her cheeks went paler, and she bit her lip.  Her whole attitude was that
of a woman aware of a bitter and tragic truth, yet, for her own honour,
she dared not divulge it.  She undoubtedly held the secret--the secret
of her father's death.  Yet, for some purpose that was yet a complete
enigma, she was protecting the impostor who had stepped into the dead
man's shoes.

The pair had brought me down there in order to entrap me--most probably
a plot of Kirk's.  Their intention was to mislead and deceive me, and at
the same time to secure my silence.  But in my frantic anxiety and
constant dread I was not easily entrapped.  I had seen through the
transparency of Kirk's attitude, and I had likewise proved to my own
satisfaction that, however much of the truth Leonard Langton knew, the
girl of the innocent eyes was feigning an ignorance that was culpable,
for within her heart she knew the truth of her father's tragic end, even
though she calmly asserted that he still lived and was in the best of
health.

I had believed on entering that room, the windows of which looked out
upon that grey-green wintry sea, that I should learn something
concerning my dear wife, that I should perhaps obtain a clue to her
whereabouts.

But as I fixed my eyes upon those of Ethelwynn Greer, I saw in them a
guilty knowledge, and by it knew that in that direction hope was futile.

True, she had sounded me as to what undertaking I was ready to give, but
the whole situation was so horrible and so bewildering that I could not
bring myself to make any compact that would prevent Greer's assassin
being exposed.

So, instead, I sat full of chagrin, telling the pair much which held
them in fear and apprehension.

It was evident that I knew more than they had believed I did, and that
Langton was filled with regret that he had invited me there.

What, I wondered, could possibly be Ethelwynn's motive in concealing her
father's death?  I recollected how the assassin must have brushed past
her in the Red Room to enter the laboratory on that fatal night, and
that he must have again passed her on leaving.

Did she awake and recognise him, or had she herself been an accomplice
in securing her father's sudden and tragic end?  Who could tell?  In
that startling suggestion I found much food for deep reflection.

CHAPTER TWENTY SIX.

I SCENT THE IMPOSTOR.

A whole fortnight went past.  Mabel's silence was inexplicable.

The house in Sussex Place was still in the hands of the caretaker, and,
though I watched both Doctor Flynn and Leonard Langton in secret, the
results of my vigilance were nil.

I was in despair.  Refused assistance by Scotland Yard, and treated as
an enemy by Kershaw Kirk, I could only sit with Gwen at home and form a
thousand wild conjectures.

Advertisements for news of Mabel had brought no word of response.
Indeed, it seemed much as though the theory of those two detectives was
the correct one, namely, that she had left me of her own will, and did
not intend to return.  Gwen, indeed, suggested this one day, but I made
pretence of scouting it.  Mabel's mother, who now lived up in
Aberdeenshire, had written two letters, and I had been compelled to
reply, to tell a lie and say that she was away at Cheltenham.

My business I neglected sadly, for nowadays I seldom went to the garage.
Kirk was, I understood, living in Whitehall Court, but I did not call
upon him.  What was the use?  I had tried every means of learning where
Mabel was, but, alas! there seemed a conspiracy of silence against me.
I had left no effort unexerted.  Yet all had been in vain.

Antonio had, according to Ethelwynn, joined "the Professor" in Hungary.
Was not that, in itself, sufficient evidence of collusion?  As for
Pietro, inquiry I made in the Euston Road showed that he had not yet
returned to England.

Many times I felt impelled to go out to Buda-Pesth and endeavour to
trace the pair.  But I hesitated, because, finding Ethelwynn's
statements unreliable in some particulars, I feared to accept what she
said as the truth.  Would it not be to her interest to mislead me and
send me off upon a wild-goose chase?

No man in the whole of our great feverish London was so full of constant
anxiety, frantic fear, and breathless bewilderment as myself.  Ah, how I
existed through those grey, gloomy March days I cannot explain.  The
mystery of it all was inscrutable.

I should, I knew, be able to satisfy myself as to poor Mabel's fate if
only I could clear up the mystery of who killed Professor Greer.

This tension of nerves and constant longing for the return of the one
for whom I held such a great and all-absorbing love was now telling upon
my health.  I ate little, and the mirror revealed how pale, careworn,
and haggard I had become.  Since the dawn of the New Year I was, alas! a
changed man.  In two months I had aged fully ten years.

From inquiries I made of men interested in science and in chemistry I
had discovered how great a man was the dead Professor, and how
beneficial to mankind had been certain of his discoveries.  Fate--or is
it some world spirit of tragic-comedy?--plays strange pranks with human
lives now and then, and surely nothing more singular ever happened in
our London life of to-day than what I have already narrated in these
pages.

And to that thin, grey-faced neighbour of mine--the man who led a double
life--was due the blame for it all.  Though I made every endeavour and
every inquiry, I could not learn what was his profession.  That he was a
man of means, a constant traveller, and well known in clubland, was all
the information I could obtain.

You will wonder, perhaps, why I did not go again to Whitehall Court and
force the truth from the fellow's lips.  Well, I hesitated, because in
every argument I had had with him he had always won and always turned
the tables upon myself.  I had made a promise which, however justifiable
my action, I had, nevertheless, broken.  I had denounced him to the
police, believing that I should see him arrested and charged.  Yet, on
the contrary, the authorities refused to lift a finger against him.

What could I think?  What, indeed, would you have thought in the
circumstances?  How would you have acted?

One morning I had gone out early with Drake, trying the chassis of a new
"twenty-four," and finding ourselves in front of the grey old cathedral
at Chichester, we pulled up at the ancient "Dolphin" to have luncheon.
My mind had been full of Mabel all the way, and though I had driven I
had paid little or no attention to the car's defects.  Dick Drake, motor
enthusiast as he was, probably regarded my preoccupied manner as
curious, but he made no comment, though he had no doubt noted all the
defects himself.

I had lunched in the big upstairs room--a noble apartment, as well known
to travellers in the old coaching days as to the modern motorist--and
had passed along into another room, where I lit a cigarette and
stretched myself lazily before the fire.

A newspaper lay at hand, and I took it up.  In my profession I have but
little leisure to read anything save the motor-journals; therefore,
except a glance at the evening paper, I, like hundreds of other busy
men, seldom troubled myself with the news of the day.

I was smoking and scanning the columns of that morning's journal when my
eyes fell upon a heading which caused me to start in surprise.  The
words read, "Steel Discovery: New High-Speed Metal with Seven Times
Cutting Power of Old."

The short article read as follows:

  "Few prophecies have been more quickly justified than that of
  Professor Greer at the Royal Institution on December 16th last.  He
  then said:

  "`As to Mr. Carnegie's prophecy on the decadence of British steel
  metallurgy, this exists only in the imagination of that gentleman.  So
  far as quality is concerned, Britain is still first in the race for
  supremacy.

  "`I am strongly of opinion that in a very short time the best
  high-speed steel will be a back number.  It is probable that a year
  hence there will be on the market British steel with a quadruple
  cutting power of any now known to metallurgy.'

  "The prophecy has come true.  Professor Greer, lecturing again at the
  Birmingham Town Hall last night, stated that the firm of Edwards and
  Sutton, of the Meersbrook Works, Sheffield, of which Sir Mark Edwards
  is the head, have, after his lengthened experiments, placed on the
  market a steel with from three to seven times the cutting power of
  existing high-speed steel, and which, in contradistinction to present
  material, can be hardened in water, oil, or blast.

  "The new steel, whose cutting power is almost incredible, said the
  Professor, will not call for any alteration in present machinery."

The impostor had actually had the audacity to lecture before a
Birmingham audience!  His bold duplicity was incredible.

I re-read that remarkable statement, and judged that this new process of
his must have been purchased by the great firm of Edwards and Sutton,
whose steel was of world repute.  His was, I presumed, an improvement
upon the Bessemer process.

That a man could have the impudence to pass himself off as Greer was
beyond my comprehension.  As Waynflete Professor at Oxford he would, I
saw, be well known, even if he did not go much into society.  And yet he
had stood upon the platform in the Town Hall of Birmingham and boldly
announced a discovery made by the man whose identity he had so
audaciously assumed.

This action of the impostor, who had no doubt sold the Professor's
secret at a high figure to a well-known firm, absolutely staggered
belief.

I called Drake, mounted upon the ugly chassis again, and together we
sped post-haste back to London.  At ten that night I was in the Grand
Hotel at Birmingham, and half an hour later I called at the house of a
certain Alderman named Pooley, who was a member of the society before
which the bogus Professor had lectured on the previous evening.

I had some little difficulty in inducing him to see me at that late
hour.  He was a busy solicitor, and his servant referred me to his
office in Bull Street, where, she said, he would see me in the morning.
But, being pushful, Mr. Pooley at last consented to see me.

"Yes," he said, as I sat with him in his diningroom, "it is quite true
that Professor Greer lectured before us last night, and made a most
interesting announcement--one which seems to have caused a good deal of
stir in the world of metallurgy.  The papers were full of it to-day."

"I understood the Professor was abroad," I remarked rather lamely.

"So he was.  He came home specially to fulfil a long-standing
engagement.  He promised us to lecture, and gave us the date as far back
as November last."

"Do you know where he arrived from?"  I inquired.

"Yes.  He dined with us here before the lecture, and stayed with us the
night.  He told us at dinner that he had just returned from Roumania."

"Then he did not leave Birmingham until this morning!"  I cried.  "Ah,
how I wish I had known!  Have you any idea where he has gone?"

"I went with him to the station this morning, and he took a ticket to
Sheffield--to visit Sir Mark Edwards, I believe.  He met at the station
a friend who had been to the lecture and who had stayed at the Grand
that night.  He was introduced to me as Mr. Kirk.  Do you know him?"

"Kirk?"  I gasped.  "Yes; a tall, thin, grey-haired man--Mr. Kershaw
Kirk."

"Yes.  They travelled together," said the Alderman.  "It seemed as
though Kirk came from London to meet the Professor, who had returned by
the Hook of Holland to Harwich, and came on by the through carriage to
Birmingham."

"And you believe that Kirk has gone with the Professor to visit Sir Mark
Edwards?"  I exclaimed eagerly.

"I think so.  If you sent a letter to the Professor at Sir Mark's
address, it's quite probable that he would get it."

"Had you ever met the Professor before?"  I inquired.

"No, never.  Of course I knew him well by repute."

"Did he mention that Edwards and Sutton were old friends of his?"

"I gathered that they were not.  He had simply concluded an arrangement
with them for working his process as a matter of business.  Indeed, he
mentioned that Sir Mark Edwards had invited him for a few days."

"Then they are not friends of long standing?"  I asked.

"Probably not.  But--well, why do you ask such curious questions as
these, Mr.--Holford!  What, indeed, is the motive of all this inquiry?
The Professor is a well-known man, and you could easily approach him
yourself," the keen solicitor remarked.

"Yes, probably so.  But my inquiry is in the Professor's own interest,"
I said, because I had to make my story good.  "As a matter of fact, I
have learnt of an attempt to steal the secret of his process, and I'm
acting for his protection.  When my inquiries are complete, I shall go
to him and place the whole matter before him."

"Your profession is not that of a detective?" he suggested, with a
laugh.

"No; I'm a motor engineer," I explained bluntly.  "I know nothing, and
care less, about detectives and their ways."

Then I apologised for disturbing him at that hour and made my way back
in the cab that had brought me to the centre of the city.

I left New Street Station at two o'clock in the morning--cold, wet, and
cheerless--and at half-past four was in the Midland Hotel at Sheffield,
sleepy and fagged.

The night-porter knew nothing of Sir Mark Edwards' address; therefore I
had to wait until eight o'clock, when some more intelligent member of
the hotel staff came on duty.

Everyone of whom I inquired, however, seemed ignorant; hence I took a
cab and drove to the great works of the firm--a huge, grimy place, with
smoky chimneys and heaps of slag, an establishment employing several
thousand hands, and one of the largest, if not the largest, in
Hallamshire.  Here I was informed that Sir Mark resided thirty miles
distant, at Alverton Hall, close to the edge of Bulwell Common, famed
for its golf links.

Therefore at ten o'clock I took train there, and, finding a fly at the
station, drove direct to the Hall to face and denounce the man who was
an accomplice of assassins, if not the assassin himself, and a bold,
defiant impostor.

The fly, after traversing a country road for a mile or so, suddenly
entered the lodge-gates and proceeded up a splendid avenue of high bare
elms, until we drew up at the entrance to a fine old Elizabethan
mansion, the door of which was thrown open by a liveried man-servant.

I held my breath for a second.  My chase had been a long and stern one.

Then I inquired for the honoured and distinguished guest--who I had
already ascertained at the works in Sheffield was supposed to be staying
there--and was ushered with great ceremony into the wide, old-fashioned
hall.

At last the impostor was near his unmasking.  At last I would be able to
prove to the world who killed Professor Greer!

CHAPTER TWENTY SEVEN.

SEVERAL REVELATIONS.

Alverton Hall, a noble old mansion, had been purchased by the Sheffield
steel magnate Sir Mark Edwards some ten years before.  In addition, I
heard that he owned a beautiful place in Glamorganshire and rented a
great deer-forest in Scotland.  He was one of England's manufacturing
princes, whose generosity to charitable institutes and to the city of
Sheffield was well known, and whose daughter had, only a year ago,
married into the peerage.

A short, bluff, bald-headed old fellow, he spoke quickly, almost
snappishly, when I was ushered into his presence in a small,
cosily-furnished room that looked out upon a fine old-world terrace,
with a Jacobean garden beyond.

"It is true that I'm expecting Professor Greer on a visit here," he
said, with a broad Hallamshire accent, in reply to my question.  "Who,
may I ask, are you?"

I explained that I was an intimate friend who desired to see him
immediately upon very important business, and that I had come down from
London for that purpose.

"Well," replied the short, active little man, "I expected him yesterday,
and cannot think why he has not arrived."

"You have had some important business dealings with him, Sir Mark, I see
from yesterday's paper?"

"Yes, very important.  He made a statement in Birmingham explaining his
discovery."

"I suppose it is a most important one?"

"Most important.  It opens up a new era in the British steel trade and
places us in the foremost rank.  At this moment no other steel in the
world can compete with that from our Meersbrook Works, thanks to the
Professor."

"You've known him a long time, I presume?"

"I've not known him personally very long," was Sir Mark's reply.  "He is
a man who has kept himself very much to himself.  But, of course, as you
know, his reputation is worldwide.  He is bringing with him his agent,
Mr. Kirk."

"His agent!"  I echoed, astounded.  "You know him?"

"Of course.  I've had several dealings with him.  He was with us in
Vienna a week or so ago."

"And was Greer there also?"

"Of course," replied the steel manufacturer.  "The contract was arranged
there."

"And who else was with him?"

"No one to my knowledge--except an English lady who lived at the
Continental in the Praterstrasse, while we were at the Grand.  She
seemed to be a friend of the Professor, for one evening he introduced me
to her.  By the way, her name was very similar to yours, I think--
Holworth or Holford."

"That was in Vienna?"  I gasped.

"Yes.  He introduced me in Leidinger's restaurant, in the
Karntnerstrasse."

"And the lady--what was she like?  Young or old?"  I inquired
breathlessly.

"Young," was his answer.

And, proceeding, he gave me a perfect description of Mabel!

"What was her attitude towards the Professor?"

"She appeared to be most eager to protect him from any suspicion of
fraud.  She seemed to regard me with some misgivings--I know not why.
Indeed, the reason of her being in Vienna and mixed up in the business
struck me as altogether remarkable, for, truth to tell, I prefer not to
deal with the fair sex in matters of pure business.  I'm a plain man,"
he added, with a strong burr in his voice, "and I believe always in
straightforward dealing, whether it be in paying a workman a day's wage
or carrying out a Government contract."

"This is all very interesting to me, Sir Mark," I said, without,
however, telling him that the lady in question was my lost wife.  "You
appear not to have approved of the lady's connection with the sale of
the patent?"

"I didn't, I frankly tell you," he said.  "I told Kirk my mind quite
plainly, but he assured me that the lady was a great friend of the
Professor."

I bit my lip savagely.  How was it that Mabel, my dear, beloved wife,
had allied herself with that pair of adventurers?  What could have been
the story told to her to induce her to become the catspaw of men of that
stamp?

It was on the tip of my tongue to tell the great steel magnate that he
had purchased a secret which did not belong to the seller, and that the
"Professor Greer" he knew was not the real discoverer.  But I hesitated.
Before I spoke I would unmask this impostor and his "agent," Kershaw
Kirk.

A word from me to this shrewd, hard-headed man of business, and the two
would, I felt assured, find themselves in the hands of the police.

Yes, I now held the trump card.  At any moment the pair might drive up
to pay their promised visit to Sir Mark.  And when they did, what an
awkward surprise would await them!

I laughed within myself when I realised how innocently they would fall
into my vengeful hands.

So communicative and pleasant was the bald-headed man that I went one
step further, daring to ask:

"I presume the price your firm paid for the secret of the new process
was a substantial one?"

"A very large one," he replied.  "A big sum down, as well as a handsome
royalty.  This must be the second fortune which Greer has made.  He has
received a lot of money for his process of hardening armour-plates.  The
Admiralty use only plates hardened by the Greer process, for here, as in
many other things, England is still ahead of Germany."

"Have you ever been to the Professor's house in London?"  I asked.

"Never.  He has, however, invited me to dine there next week."

"Next week!"  I cried.  "Then, of course, you'll go?  You'll probably
find Kershaw Kirk there."

"Yes," he laughed; "most probably.  He's a strange man--isn't he?--and
most influential."

"He's certainly strange, but as regards his influence, I know nothing,"
was my quick reply.

"Why, my dear sir, his influence is enormous!  He can go direct to
quarters where we are entirely debarred!" declared my companion, as I
sat back in the chair listening to these revelations.

"How?  I don't follow you."

"Well," he declared, "to me, the reason of Kirk's influence is a
complete mystery, but it has been conclusively proved more than once
that he has the _entree_ to the highest quarters, and the ear of the
authorities."

I laughed.

"I suppose he has misled you into the belief that he has, Sir Mark.
He's a boaster--like many other men of his stamp."

"He's a boaster and a trifle eccentric, I admit.  Yet I have myself had
experience of his undoubted influence.  He's in some position of great
trust."

"There, I fear, I must differ, Sir Mark.  I happen to know him well, and
I think one day ere long you'll discover that his powers are merely
imaginary."

The short, bald-headed man shrugged his shoulders dubiously, whereat, in
order not to go contrary to his opinion, I turned our conversation into
a different channel.  I had already learned much of interest, but much,
too, that had caused me a twinge of despair.

We spoke of other things, and apparently impressed by the fact that I
was eager to meet Greer, he invited me to wait until he and Kirk
arrived.

"But they may not be coming, after all," I said.  "They may have changed
their minds."

"I think that hardly probable," Sir Mark replied.  "They have been
delayed, though I've ascertained that they left Birmingham to come
direct here."

I told him nothing of my visit to Alderman Pooley, but my only fear was
that, with the report of the bogus Professor's speech appearing in the
papers, the impostor had become alarmed and again made himself scarce.
To me it appeared much as though he and his accomplices had never
intended the announcement to get into the papers.  Indeed, even Sir Mark
had expressed himself surprised at reading the report, understanding
that the meeting was a purely private one of the learned society which
had invited him to lecture.

I smoked a cigar with the affable little man, and then he left me, being
called to the telephone.  When he re-entered the room, he said:

"I've been speaking to the Professor.  It seems that he's at home, at
his house in London.  He was recalled suddenly by telegram, and not
having been home since his return from the Continent he was compelled to
obey the summons.  He promises to come here next Monday."

My heart sank once more within me.  The truth was just as I had feared!
The report of his speech in the papers had alarmed him, and he was no
doubt on his way abroad again, having netted a goodly sum from Messrs.
Edwards and Sutton for a secret filched from the unfortunate man who had
been assassinated.

"Then I'll go back to London at once," I announced; and, without
betraying my anxiety to my bald-headed friend, who had been so cleverly
victimised, I bade him adieu, and an hour later left Bulwell for London.

In the grey March afternoon I alighted from a hansom before that
well-remembered door of the Professor's house in Sussex Place.  I did
not for one moment believe him to be there.  He had, of course, escaped
long ago.  In Edinburgh and in Glasgow I had been close at his heels, as
I had also been in Birmingham, yet he had always cleverly evaded me.

To my amazement my ring was answered by Antonio--sleek, smiling, yet as
evil-faced as ever!

"Is your master at home?"  I asked sharply, for I certainly had not
expected to meet the man who had escaped to Italy, and who had
afterwards threatened me.

"No, signore," was his bland reply.  "He is out at present."

"Then he--he's at home again?"

"Yes, signore.  He returned unexpectedly yesterday."

"And Miss Ethelwynn?"

"The signorina is still at Broadstairs; we expect her up to-morrow."

"And my wife, Antonio--where is she?"  I inquired, looking him straight
in the face.

"Ah, how can I tell, Signor Holford?  Have I not already told you that I
am entirely ignorant of her whereabouts?"  And he exhibited his bony
palms.

"You have been with your master in Hungary or in Roumania, I hear?"

"Certainly!  Why not?" he said, as we stood within the wide hall.  "But
the Signor Kirk is upstairs in the study.  Perhaps you will care to see
him?  I believe he has been trying to telephone to you at Chiswick."

I started in eager anticipation.

"Of course, I'll see Mr. Kirk," I said.

And endeavouring to steady my nerves and control my temper, I mounted
the thickly-carpeted stairs to the room I so well remembered.

The point which puzzled me was whether I should now boldly accuse Kirk
of duplicity and fraud.  If I did, I feared that, to the bogus
Professor, he might give the alarm, and that he would again slip through
my fingers.

On my way to the study I resolved upon a purely diplomatic course.  I
would not let Kirk know of my visits to Birmingham and Sheffield, or
even that I had noticed the report of the Professor's announcement.

For a second I held my breath.  Then I turned the handle of the door and
boldly entered.

"Why, my dear Holford," cried Kirk, jumping up from the writing-chair
and grasping my hand as though delighted at my visit, "I've been trying
to get on to you at your garage three times this morning, but your
people have been engaged.  You must be pretty busy down there--eh?"

The thin-faced man was, indeed, a perfect actor.

"I called to see Antonio," I said.  "I heard he had returned."

"Then it is fortunate--most fortunate," he said.  "I am awaiting the
return of someone who is very desirous indeed of making your
acquaintance.  It was for that reason that I've been trying to ring you
up."

My lips parted in an incredulous smile.  So the impostor was anxious to
meet me--doubly anxious, no doubt, because he was aware that I knew the
truth of poor Greer's death.

Yes, I would meet and unmask him.

CHAPTER TWENTY EIGHT.

"NO TRUMPS."

In the failing London light, as Kirk rose and stood near the window, his
countenance was even more sinister and more mysterious than ever.  About
his lips played that enigmatical, sarcastic smile which so tantalised
and irritated me.  Here was a man who had actually deceived the
hard-headed Sheffield magnate into a belief that he possessed power and
influence, while, in reality, he was only a clever adventurer.

"Sit down, Holford," he said, in a cheery voice, inviting me to a big
leather arm-chair.  "The time has come when it is very necessary for you
and me to arrive at some clear and definite understanding."

"Yes," I cried, "I agree with you.  Have I not asked you all along for a
clear statement of facts?  Have I not urged you to tell me where I can
find my wife?"

"You have," he said, leaning against the big, old-fashioned mahogany
table piled with books and scientific periodicals.  "But until the
present I have been unable to satisfy you.  Even now I am still in a
great measure in the dark as to the--well, the unfortunate occurrence,
shall we call it?--which took place in this house."

"But you have, I understand, been acting in concert with the man who
calls himself Greer?"  I remarked.  "You've been with him abroad!"

"I don't deny that.  Why should I?"

I shrugged my shoulders impatiently.  His evasion was always cunning,
always well-contrived.

"When you first brought me here," I said, "it was to obtain my
assistance to discover who killed Professor Greer, and--"

"And you made a promise which you did not keep!" he interrupted.  "Hence
I have been unable to keep faith with you.  Is not that quite feasible?"

"My wife's disappearance is the point which most concerns me," I said.
"The other matter is, to me, of secondary importance.  If you cared to
divulge, you could tell me my wife's whereabouts.  I happen to know that
she has been in Vienna, staying at the Hotel Continental, and she has
been seen in your company, Mr. Kirk."

"Now that's really quite smart of you!" he laughed, with a patronising
air, his grey face changing slightly, I thought.  "I wonder how you came
to know that?"

"The source of my information does not matter," I said sharply.
"Suffice it that it is a reliable one."

"Well," he laughed, "since that evening when you sat with me in Bedford
Park I've been compelled to be active, and I've discovered quite a
number of things which at that time I never dreamed--facts that have
amazed me, as they will, before long, amaze you, Holford."

"Nothing can amaze me in this crooked affair," I declared.  "You sought
my aid in an endeavour to discover who killed Professor Greer, yet,
having gained my confidence, you at once abused it!"  I cried, with
bitter reproach.

"That is your present opinion," he said, with a keen, crafty look.

"An opinion based upon your actions towards me!"  I exclaimed hotly.

"My dear Holford," he said, "now let us speak quite frankly, as man to
man."  And he bent towards me in an eager attitude.  "I put it to you
whether, in the circumstances--not overlooking the fact that Scotland
Yard has refused you assistance--to forget what you saw that night
upstairs in the laboratory, to place it aside as though you never
witnessed it, is not the best plan?"

"Ah, you wish still to hush up the tragedy!"  I cried.  "The reason is,
of course, quite obvious."

"You misinterpret my words.  I wish to avoid bringing scandal upon
innocent folk," Kirk replied quickly.  "You once gave me a pledge of
secrecy, and you broke it.  Will you give me another?"

"And if I gave it," I asked, not without some hesitation, "would these
precious friends of yours give me back my wife?"

"I cannot answer for others.  Personally, I will do all I can to assist
you," was his somewhat evasive reply.

"Why do you wish to extract this promise from me?"  I demanded
dubiously.

"Because--well, because you must give it.  You _must_ remain silent,
Holford.  It is imperative!"

"You really ask too much of me," I laughed sarcastically.  "I know the
ghastly truth.  You showed it to me of your own accord--you yourself
drew me into this dark, mysterious affair, and now you coolly demand my
silence, because you are, I suppose, interested in the money realised by
the sale of Professor Greer's secret."

"Ethelwynn Greer makes the same demand as myself," he said calmly.
"Surely you don't believe that the girl has participated in any
shamefully obtained profits?"

"The girl saw her father dead, and now refuses to admit it," I
responded.

"How do you know that she did?" he asked.  "What actual evidence have
you upon that point, beyond my word--repeated from the story told to me
by Antonio?"

"Ah! so Antonio is changing his tale in order to fit the new order of
events--is he?"

"Well," Kirk said, after a brief pause, "that there is a new order of
events--as you put it--I admit.  Yet, whatever they may be, your
silence, Holford, as well as mine, is imperative.  You hear that!" he
added, looking straight into my face.

"To hear and to heed are scarcely synonymous," I remarked in anger.  I
was incensed with this man who refused to give me any satisfaction
concerning Mabel, and yet commanded my silence.

Was it not a very curious feature of the affair, I reflected, that
Ethelwynn had ingeniously approached me, offering me news of Mabel in
return for my undertaking to make no further inquiry into her father's
secret death?  How much did Langton know, and what was the extent of the
knowledge of that friend of his, the specialist in diseases of the
throat and nose?

For a few moments I sat in silence, longing for the return of the bogus
Professor, the man whom I had followed through Edinburgh and Glasgow,
yet who had so very cleverly escaped my vigilance.

I was anxious to meet him, and to see what kind of man he could be.  As
an impostor he was, it seemed, shameless and bold beyond human credence.

How many thousands had Edwards and Sutton paid to him for that great
secret that was not his own?

Antonio, suave and cringing, suddenly put his head in at the door,
asking:

"Did you ring, signore?"

"No!"  I cried, rising angrily, "Mr. Kirk did not ring.  I suppose
you've been listening outside--eh?  You are one of the accomplices in
the murder of your master--and by Heaven, you shall pay for it!  If
Scotland Yard will not help me, then I'll take the law into my own hands
and give the public an illustration of the red-tape and the uselessness
of the police!"

"The signore is a little excited!" was the man's quiet remark to Kirk.

"Excited, by Heaven!"  I cried.  "I'll be fooled no longer by any of
you--band of assassins that you are!  You ask me to believe that black
is white, and tell me that my own eyes deceive me.  But I'll be even
with you yet--mark me!"

"Pray calm yourself, Holford," said Kirk, shifting his position slightly
and still leaning easily against the table, "No good can be served by
recrimination."

The man's cunning was unequalled; his ingenuity almost superhuman.  Once
I had held him in awe, but now, knowing the truth, that I held
information which it was his earnest desire to suppress, I felt
triumphant.

"I admit," he said, still speaking calmly, as Antonio disappeared and
shut the door--"I admit that there are certain ugly facts--very ugly
facts which are difficult to forget, but is it not better to be merciful
to the innocent and living than to revenge the dead?"

"You desire to seal my lips, my dear sir," I said.  "Why don't you speak
quite plainly?"

"Yes," he admitted, "I make that appeal to you because--well, for
several very strong reasons--Ethelwynn's future being one."

"And what, pray, need I care for that girl's future, now that mine has
been wrecked by the devilish machinations of you and your gang?"  I
cried in bitter anger.

"Your denunciation is quite uncalled for, Holford!" he exclaimed.

"It is not," I protested.  "You know where my wife is, and you refuse to
tell me!" was my quick answer.

"Please don't let us discuss that further," he urged.  "The point is
whether you will, or you will not, regard all you saw in this house a
couple of months ago as entirely confidential."

"Why?"

"For reasons which you shall know later.  I regret that I cannot explain
at this moment, because I should be breaking a confidence," he
responded.  "But," he added, looking at me very seriously, "a life--a
woman's life--depends upon your silence!"

I hesitated a moment.

"Ah, I see!"  I cried.  "Then the girl conspired to encompass her
father's end, and is now in fear of the impostor!"

"I must leave you to your own opinion," he said, with a shrug of his
thin shoulders.  Then, turning away to the window, he thrust his hands
into his pockets, and, with that cosmopolitan air of his, he hummed a
verse of that catchy song of the boulevards he so often sang.

CHAPTER TWENTY NINE.

I AM FACED WITH ANOTHER DIFFICULTY.

The careless manner in which Kirk seemed to treat the grave issue of my
life enraged me.  This man, who in Chiswick posed as shabby and
broken-down, was certainly no ordinary person.  He was a shrewd, clever
adventurer, possessed of resources that had even astonished Sir Mark
Edwards.  He had entrapped me, for some hidden reason of his own, and
now he held me in a hateful bondage.

But with the vivid recollection of Mabel upon me, I resolved to defy
this enemy of mine at all costs.  I was only awaiting the return of the
false Professor to unmask the pair, to call a constable, and to give
them both in charge.

What the result would be, I cared not.  I should, however, at least be
afforded an opportunity to make revelations in the police-court which
they would find it somewhat awkward to refute.  Surely by doing this I
should be performing a work of public benefit?  The pair were clever
swindlers, reaping the harvest from that secret discovered by the
unfortunate man who had been purposely killed.

"You appear, Mr. Kirk, to consider me an absolute fool!"  I said,
interrupting his song.

"I do, my dear Holford, I do.  You have acted against your own
interests, and even now you are spitting against the wind."

"You desire my silence, yet you offer me nothing in return!"  I said.

"Oh, you want payment!" he cried.  "My dear sir, you have only to name
your own price.  We shall not quarrel over it, I can assure you."

"No," I said angrily, "I desire no blood-money, even though it is to
save Ethelwynn Greer.  I have all along suspected her of some complicity
in the affair, although on the night you removed her to that house in
Foley Street she accused you of the crime!"

He started quickly and turned to me, his countenance slightly paler.

"Repeat that," he said quietly.

I did so.  I told him how I had followed him to Foley Street, of the
screams and words I had heard while standing in the fog outside the
house.

"H'm.  So you think I'm guilty of the crime, eh?" he said simply.

"I repeat the girl's allegation against you," I said.  "And yet this
same girl now declares that the Professor is not dead!"  Then I added:
"He was dead when we were together in the laboratory, was he not?  Come,
speak plainly!"

"Certainly he was!"

"And men do not come to life again when once dead, do they?"

"But this is an unusual case, I tell you.  He--"

"However unusual, you cannot alter the laws of life and death," I
declared.

"Well, my dear Holford, how I wish I could reveal to you one simple
truth.  It would astound you, no doubt, but it would at the same time
alter your opinion of me."

"Oh, of course," I laughed bitterly.  "You're not so black as you're
painted--you who have conspired to hold my wife aloof from me--you who
for aught I know have told her some infamous tale which has caused her
to look upon me with doubt and horror!  I have recently learnt that she
was acquainted with this man who calls himself Ernest Greer, and that,
before she left my roof, she received word in secret from him."

"Your wife's affairs are surely of no interest to me, Holford," said the
grey-faced old scoundrel.  "I am merely putting forward to you a simple
matter of business--in a word, making a proposal for your
consideration."

"A proposal which I will never accept--_never_, you understand!"  I
added with emphasis.

"Not if I appeal to you on behalf of Ethelwynn, on behalf of a girl
whose very life is dependent upon your silence?" he asked earnestly.

"The punishment for murder is death," was my hard response.

He regarded me steadily, without speaking.  I saw that he realised my
steadfastness of purpose, and that I meant to reveal the truth to all
the world.

"But," he cried at last, "you surely will not act as a fool, Holford!  I
told you on the night we first sat together of the great issues that
depended upon your silence, and I repeat it now."

"Why did you entice me into this complicated tangle of crime and
mystery?"  I demanded quickly.  "Tell me that."

"Because--well--" And he hesitated.  "Because I--I was a fool--I admit
it frankly.  I ought never to have approached you.  Three days later I
regretted it deeply."

"Regretted it because you found, to your surprise, that you had no fool
to deal with!"  I cried.

"No; because I had made a mistake in another direction.  But--but,
hark?"

I listened and heard a footstep outside on the stairs.

"The Professor!"  Kirk exclaimed.  "He has returned.  I'll introduce
you."

I rose from my chair, my teeth set together, my hand gripping the edge
of the table.

An instant later the door opened, and I stood boldly face to face with
the impostor.

Kirk, with that calm suavity of manner that so annoyed and irritated me,
introduced us.

But I bowed coldly to the well-dressed, elderly impostor, a man with
keen, deep-set eyes, and a short, scrubby grey beard, asking of my
companion:

"Is this farce really necessary, Mr. Kirk, when I know the truth?"

The new-comer looked askance at his accomplice, who gave him a quick,
meaning look.

"Ah! my dear Mr. Holford!" exclaimed the bogus Professor, "I've been
most anxious to meet you for a considerable time.  This is a great
pleasure."

"And one which I most heartily reciprocate," was my hard reply.  "I've
been endeavouring to find you for a long time.  I followed you in
Edinburgh, in Glasgow, and later on in Birmingham."

"Then surely it is a rather happy circumstance that we have met to-day?"
he said, rather fussily.

"Happy for me, but perhaps unhappy for you!"  I replied, with a dry
laugh.

"Why?"

"Because I now intend to expose your very clever plot.  The secret you
have sold to Sir Mark Edwards does not belong to you at all, but to
Professor Ernest Greer, the man who was killed in the room yonder--in
his own laboratory!"

His lips grew paler and set themselves hard.  I saw in his dark eyes an
expression of fear.  He held me in terror--that was quite plain.

"Holford, you are mistaken," declared Kirk.

"In what way?"  I demanded.

"Professor Ernest Greer stands before you!"

"No!"  I cried.  "This man is the impostor--the impostor who wrote to my
wife, and enticed her from her home."

"I wrote to Mrs. Holford, certainly," was the fellow's cool reply.  "But
without any evil intent; of that she will herself assure you."

"Where is she?"

"You will, no doubt, see her before very long, and she will explain the
reason of her absence."

"Ah!"  I said, "you adventurers dare not tell me the truth with your own
lips.  Remember, I saw the Professor lying dead in this house.  You
cannot induce me to believe that my eyes deceived me!"

"And yet you see the Professor alive before you now!" declared Kirk with
a triumphant laugh.

But I made a gesture of disgust, declaring that I refused to be fooled
further.

"You are not being fooled, Mr. Holford," asserted the man in a calm,
distinct voice, as he opened the door and called to Antonio.

The grave-eyed man-servant entered in a few seconds, and as he did so
the new-comer said: "Antonio, will you please tell this gentleman who I
am?"

"You are my dear master, signore--the Signor Professor Ernest Greer."

"I already know, Antonio, that you're a clever liar," I cried, "so you
can retire."

"The Signorina Ethelwynn has just arrived, signore," remarked the highly
respectable manservant.

"Ah! then tell my daughter to come up?" he cried.  "She will no doubt
satisfy Mr. Holford that I am no impostor."

"Miss Ethelwynn saw her father lying dead, as I did; how, therefore, can
she identify you as her deceased parent?  Have you a half-brother, or
some relation strongly resembling you?"

"No, I have not," was his quick reply.  "I am simply Professor Ernest
Greer, whom a thousand persons living can identify."

At that moment the fair-haired girl neatly attired in fur jacket,
tailor-made skirt, and toque entered, and, with a spring, fell into the
impostor's arms and kissed him.

That piece of acting was, without doubt, perfect.  Yet I stood aside and
smiled.  Had not Kirk previously admitted to me that his earnest
endeavour was to secure my silence?

"Am I your father?" asked the dark-eyed man of Ethelwynn, standing with
his hand upon her shoulder.

"Of course you are, dear dad!  Why?"

"Because this gentleman will not believe it!" he laughed.

"This is my father, Mr. Holford," the girl declared, turning to me.

"But did not you, with your own eyes, see your father dead in his
laboratory?"  I asked seriously.  "Are you not being misled, as these
men are trying to mislead me?"  I suggested.

She hesitated, glancing towards the man who posed as the Professor as
though expecting him to reply for her.

"No," I went on, "this is a conspiracy--a plot to place this man in a
dead man's shoes.  And you know it, Miss Ethelwynn."

"I tell you he's my father!" the girl persisted.  "Cannot you believe
us?"

"Not without some independent proof," I said.  This persistence angered
me.

"Then what proof do you require?" asked the man.  "Shall I call the
park-keeper at Clarence Gate?  He has known me and seen me every day for
a number of years."

"Call him, if you wish," I said, though, truth to tell, I did not intend
to be longer fooled by the ingenious machinations of Kirk and his gang.

Antonio was sent to find the park-keeper, who, in due time, appeared,
carrying his gold-laced hat in his hand.

"You've known Professor Greer a long time?"  I asked the white-headed
man.

"Several years, sir," was his quick reply.

"And do you recognise this gentleman as the Professor?"  I asked.

"Certainly, sir; I saw him pass in at the gate this morning.  He's cut
off his beard, and that makes a bit of difference to a man, you know!"

He laughed.

"You have no hesitation in identifying him, eh?"  I asked.  "You'll be
able to swear to him in a court of law?"

"Yes, sir, in any court of law.  The Professor's been very kind to me,
once or twice; therefore it isn't likely that I forget either his face
or his voice."

This bewildered me.  Was it possible that this impostor was the
Professor's twin brother?  I felt confident that Kirk was continuing
some very ingenious conspiracy.  Was not his suggestion to me that I
should forget the tragedy sufficient proof of double dealing?

I thanked the park-keeper, who withdrew with Antonio, whereupon Kirk
asked me whether I was not satisfied.

"No," I said, "and I shall never be satisfied until I discover the
identity of the man who killed Professor Greer."

"But Professor Greer stands before you!" declared Ethelwynn; "nobody
killed him!"

"So you wish me to believe," I said with a smile, "but as my secrecy has
been demanded on your account, I can only suspect that you were, in some
way, implicated in the crime."

She went pale as death.  My words, I saw, had a startling effect upon
her.  She looked first at Kirk and then at the man posing as her
father--the man who had secured many thousands of pounds for a secret
that was not his own.

"Then you refuse to accept even the park-keeper's testimony?"  Kirk
remarked, while the man who had assumed the Professor's identity walked
across to the writing-table and began looking at some letters lying upon
it.

"I do; my intention is to unmask you all!"  The impostor, the fading
light falling upon his clear-cut countenance, turned quickly, and upon
his face rested an expression of deadly fear that I had not previously
noticed.  Hitherto his attitude had been one of bold unconcern.  But
now, realising my determination, he had grown alarmed.  He saw that he
had carried the imposture too far.

"Ethelwynn," he said, in a low, strained voice, "I--I wish to speak with
Mr. Holford.  Will you leave us for a little while, dear.  Go into the
Red Room, and we'll join you there later."

"My dear sir," I exclaimed, "I don't desire to hear any more of your
denials."

"I'll go, dad, of course," replied the girl, who, in obedience with his
suggestion, left the room.

I turned to follow her, but with a sudden movement he placed himself
before the door, exclaiming anxiously:

"Mr. Holford, pray hear me for one moment, I beg of you.  I want to tell
you something--to confess!"

"Ah!"  I laughed triumphantly.  "At last! you will confess!  Good!  I am
all attention."

"Listen carefully to the facts, Holford," urged Kirk.  "The Professor's
peril lies in the knowledge possessed by one man--yourself.  It is
therefore but just that you should know the truth."

"I do not expect the truth from you," I laughed.  "How can I, after all
that has passed?"

"The deceit I've practised upon you has been imperative," was his
audacious answer.

"Let me explain," interrupted the impostor, advancing to the fireplace
near which I stood.  "First, I repeat that I am Professor Ernest Greer,
and that this is my house.  My statement can be verified later, but for
the present I ask you to accept it as the truth.  My old friend here,
Kershaw Kirk, is not an adventurer, though he so often poses as such.
But it is under necessity, for his real profession is that of a
confidential agent of the British Government, the trusted head official
of our Intelligence Department."

At this I smiled incredulously, wondering what fantastic story he was
about to relate, for even then I did not recognise him by the photograph
I had obtained just before going up to Scotland.  He was thinner, and
his eyes were quite unlike those of the photograph, being narrower and
deeper set.

"The plain facts are as follows," he went on, after a second's pause.
"I had been experimenting until I had discovered an easy method of
obtaining from the air those subtle elements helium and neon.  My
success had incidentally confirmed Sir William Ramsay's estimation that
the proportion of neon and helium in the atmosphere was about one to two
in each hundred thousand, when a suggestion occurred to me that my
process of hardening armour plates might be improved upon, and a
substance of great cutting power created.  My experiments were long and
tedious, but were at last crowned with success.  I very foolishly gave,
in the French scientific journal _Cosmos_, some account of these
experiments, and a month later I was secretly informed by Kirk that the
German Government--always our rivals where improvements in war material
are concerned--was actively endeavouring to obtain my secret.  As you
know, I always kept my laboratory locked, and allowed no one within upon
any pretext.  My only confidante was my daughter Ethelwynn."

And again he paused, glancing across at where Kirk stood, narrow-eyed
and silent.

"Well," he went on, "after another month had passed, Kirk returned from
Germany, where he had been upon a secret mission for the Government, and
then he urged me to exercise the greatest care.  A very clever German
agent, by name Max Leftwich, who had resided in London for some years,
had been instructed to obtain my secret at all hazards.  Kirk warned me
that he was a man of remarkable tact and ability, and that under his
control were fully a dozen agents rendering him assistance.  It was he
who had obtained for his employers in Berlin the secret of our new
submarine boat, and who had controlled the survey of the Suffolk coast
in view of the coming invasion.  I confess that I laughed at Kirk's
fears--fears which were repeated to me by one of the Lords of the
Admiralty only a week later.  I saw no reason, however, for any serious
apprehension.  My laboratory was always locked, and could not be entered
either from the skylight or conservatory, while the only keys of those
double doors were secure upon my chain.  But, alas!  I had, like many
another man, foolishly lulled myself into a sense of false security."

And he sighed as he again paused.

CHAPTER THIRTY.

I DISCOVER MUCH THAT IS AMAZING.

"Well," continued the dark-eyed man, "the rude awakening came in the
following way.  The thirteenth of January was on Sunday.  Kirk, who had
been engaged in watching the movements of the secret agent Leftwich,
sent me a telegram telling me to leave for Edinburgh at 11:30 that
evening, and asking me, if I intended to carry out this suggestion, to
raise and lower the drawing-room blind three times at a quarter past
five.  By that I knew that the German agent and his friends had some
desperate game afoot and that Kirk, astute and active, intended to
prevent them carrying out their object."

"If anyone obtained access to the laboratory, then, they could steal the
secret?"  I asked.

"They could obtain specimens of the steel which might be analysed," he
said.  "And these specimens, in conjunction with the written results of
my experiments, kept in the safe here, in this room, would, of course,
place my process in their hands."

"Then you were acting in obedience with Kirk's suggestion," I said.  "He
wished you to go to Scotland out of the way, eh?"

"Exactly.  He had previously been ordered by the Government to keep
watch over me, for it was known by the Intelligence Department that
Germany would make a desperate attempt to obtain the secret of what, to
them, would be a most valuable process in the preparation of steel for
use in their new navy."

"And you made the signal to Kirk?"

"Yes.  I told Ethelwynn nothing, fearing to alarm her.  I merely
remarked that I was compelled to go to Scotland, my intention being to
take her with me at the last moment.  I did not dress that night, it
being Sunday.  We dined at eight, and afterwards Antonio packed my bags.
After dinner my daughter went up to the drawing-room, while I came in
here to the study, in order to write some letters and attend to one or
two things before departing.  At a quarter to ten I recollected that I
should remove a small crucible from the furnace wherein I had placed it
that afternoon, and, passing through the Red Room, I found, to my great
surprise, the two doors leading to the laboratory had been unlocked, and
were slightly ajar.

"Suspecting something amiss, I dashed in, to find to my amazement an
intruder there--the man Leftwich, dressed exactly to resemble myself!
He had in his hand some specimens of the new steel, and as I entered
noiselessly he was in the act of bending over a memorandum book, reading
some notes I had made that day.  You may imagine how amazed I was to see
my second self standing there before me!  I faced him, demanding to know
what he wanted.  I saw that he must have entered with keys made from wax
impressions somehow taken from my own, and that his object in making up
to resemble me was in order to pass upstairs within sight of the
watchful Antonio or any of the other servants.  Indeed, it was
afterwards proved that Antonio saw him pass up immediately after dinner,
and believed him to be myself."

"Is this a fact?"  I gasped.

"The truth," declared Kirk; "but listen to the end."

"Well," faltered the Professor, "on being challenged, the man, seeing
himself cornered, instantly attacked me with a knife.  I closed with
him.  He tried to kill me and escape.  Ah! it was an exciting moment--
his life or mine!  I shouted, but Antonio did not hear me.  The fellow
got me by the throat and lifted his hand to strike.  He cut my little
finger badly.  Then suddenly he slipped upon the tiles, and in an
instant I had pinned him down.  I wrenched the knife from him, and--and
I struck him.  He--he fell dead in the corner!  I stood aghast at what I
had done.  I had saved the secret--prevented it from falling into the
hands of Britain's enemies, but I had killed the German agent, who had
apparently escaped Kirk's vigilance.

"What to do next I did not know," continued the Professor.  "I stood for
a few moments horrified at my action.  Suddenly it occurred to me that,
being dressed exactly like me, it would be believed that I had been
assaulted!  But his features were not mine, so I took a bottle of highly
corrosive acid and flung it into his face, and then exchanged my gold
watch and keys for his, and put some of my letters into his pocket.
Afterwards I replaced the one or two things that had been disordered in
the laboratory, switched off the light, and, leaving the dead spy in the
corner, closed both doors, which, as you will see, lock automatically."

"And then?"  I asked, amazed at his story.

"Then I came in here, put a piece of plaster upon my finger, opened the
safe, and took the precious books containing the records of my
experiments, in order to make it appear that a robbery had been
committed.  After washing myself in my room, I strove to preserve an
outward calm, and asked Ethelwynn to telephone for a sleeping-berth for
me.  I had now decided, as there was no further danger of spies, not to
take her with me.  Just before I left, I came in here and wrote her a
letter, telling her I should be absent some months, and instructing her
to call Kirk and regard him as her protector during my absence.  As I
went out I left the note beneath the salver on the hall table, so that
it might be discovered by the maid when dusting in the morning.  At
11:30 I left King's Cross for Edinburgh, without, however, being able to
communicate with Kirk or tell him what had actually occurred."

"I, on my part, naturally believed that the dead man was the Professor,"
Kirk interrupted.

"And when were you aware of the truth?"  I asked.

"The day after I had called you in consultation.  I then saw that, in
exposing an affair which, at all hazards, must be kept a secret, I had
acted most injudiciously.  I did not dare to tell you the truth.  I went
to Edinburgh and found the Professor, who was in hiding, fearful lest
the affair should be discovered.  He told me exactly what had occurred,
and invoked my aid.  My agents watched every move you made.  They were
with you in Edinburgh and in Glasgow.  Therefore, I was well aware how
strenuously you were seeking a solution of the mystery."

I paused in sheer amazement.  As I reflected, I saw that Kirk had been
shielding his friend the Professor all along.

In reply to my questions, he told me that the reason why he could not
satisfactorily prove an alibi if accused of the crime was because at the
hour of the tragedy he was engaged upon a mission for the Government, a
secret transaction with an agent of another foreign Power which was
greatly to our advantage, and betrayal of which would create serious
international complications.  His allegations of enmity towards the
Professor had been made to mystify me.

He added, also, that the reason why the Commissioner of Police had not
listened to my story was because I had made accusations against him.
They knew him at "the Yard," he added with a laugh, and it was not
likely they would dare to make inquiry into his actions.

"But I saw Miss Ethelwynn lying dead!"  I said, turning to the
Professor--for how could I now doubt that it was actually he?

"Let my daughter relate her own story," he said; and, going to the door,
he recalled her.

"Just tell Mr. Holford, dear, what occurred to you on that evening when
you returned from your aunt's," he said, as she entered the room.  "I
have confessed to him the truth."

"Well, dad," she said, "I believed that the man in the laboratory was
you yourself.  Besides, Mr. Kirk believed it to be you.  The face was,
of course, much disfigured, but the clothes were yours, and in the
pockets were your watch and some of your letters.  I was insane with
grief, and with Morgan, to whom Mr. Kirk told a fictitious story, I went
to Lady Mellor's.  On the night in question something seemed to prompt
me to return home, enter with my latch-key, and go up to the laboratory
to make sure that it was really you.  I somehow could not believe that
you were dead.  Remember, I was in the Red Room all night, and you would
certainly have awakened me if you had entered and unlocked the door.  So
I went.  I crept in softly, in order that Antonio should not hear me,
and, ascending to the laboratory, switched on the light.  I examined the
body closely.  Ah! it was a gruesome sight--but I satisfied myself that
it was not you!  I crept downstairs, back to the dining-room, but as I
entered something was suddenly flung over my head; I smelt a curious
odour--it may have been some anaesthetic.  I tried to scream, but could
not, and in a few moments I became unconscious.  When I regained my
senses I found myself in a strange house, with Mr. Kirk bending over me.
I believe I was delirious, for I remember shouting and raving, and
charging him with an attempt to kill me.  It was impressed upon my
unbalanced mind that he had killed my father.  But, on the contrary, he
was all care and attention.  On putting my hand to my face I found upon
my cheek a quantity of what seemed like wax, which peeled off in my
hand."

"And you afterwards went down to Broadstairs?"  I said.

"Yes; I went with Morgan on the following day."

"But who had attacked you in the diningroom?"

"Ah! that remains to be proved," replied Kirk.  "A desperate attempt
was, no doubt, made upon Miss Ethelwynn by somebody who had entered the
house secretly for the same purpose as herself--by somebody who
suspected that Leftwich had come to an untimely end.  The would-be
assassin first administered an anaesthetic, and must afterwards have
injected with a hypodermic syringe some curious poison, which gave to
her all the appearance of death, though the dose was fortunately
inefficient.  With the remembrance of Leftwich's features--which he had
only seen a few minutes before--being disfigured, it seems that her
assailant tried to disfigure hers by pouring upon her face hot wax from
the candles alight upon the dining-room table.  It was, of course, the
act of a person half demented by the desire for revenge."

"And you are unaware of who did this?"

"I have a suspicion--a slight suspicion.  It is for me to prove its
truth."

"You will now see the terrible position in which I have been placed, Mr.
Holford," exclaimed Ethelwynn.  "I knew that my father had killed a man.
Was it surprising, therefore, that I should endeavour to shield him?"

"Certainly not," I said.  "You acted only quite naturally.  My chief
complaint is that you have all kept my wife aloof from me."

"We will speak of that later," Kirk interrupted.  "Let me continue.
When I had been up to Edinburgh, and knew that the Professor lived and
was in hiding, I returned and set to work to remove all traces of the
unfortunate affair.  To allow the facts to leak out to the public might
have provoked a serious quarrel with the German Government, and I could
not afford to allow that.  Therefore, on the night when Langton saw the
light in the drawing-room, Ethelwynn, who had come up from Broadstairs,
Pietro, and myself had made up the furnace, and together we got rid of
the gruesome remains, after which we ate a hasty meal.

"I had previously sent Antonio to Italy for a holiday, deeming it best
in the circumstances that he should be absent.  Ethelwynn and Pietro had
left the house, when, of a sudden, I heard the bell, and, peeping out,
saw Langton at the door.  It was an exciting moment.  The young man had,
I knew, had his suspicions aroused by meeting Antonio at Calais, for
Antonio had wired me that he had been recognised.  So I waited until
you, very fortunately, came, and allowed me to escape."

For a moment I was silent.  Then I said: "You'll remember when we
returned to Bath Road after my first visit to Sussex Place you were rung
up on the telephone.  The message caused you great alarm.  What was it?"

"Antonio told me of his suspicions that the dead man was not the
Professor," was his reply.

"And on your second visit to this house you signalled by the blind of
the drawing-room, as the Professor had done."

"I signalled to Pietro, who was out in the fog, that you were still with
me.  He had, of course, been with Ethelwynn to Foley Street, and I was
about to go there."

"And, tell me, what connection had Doctor Flynn with the affair?"  I
demanded, utterly astounded at the very remarkable story unfolded.

"Listen--and I'll tell you the whole truth," Kirk said; and, pausing, he
looked at both father and daughter, as though to obtain their consent to
make further revelations, and thereby elucidate what was certainly the
most extraordinary mystery of modern times.

What I had heard was startling enough, in all conscience, but what I was
yet to learn was still more astounding, as you will see.

CHAPTER THIRTY ONE.

I AM AGAIN PERPLEXED.

As we spoke, Antonio entered, and handed his master a note, which, on
reading, he handed in turn to Kirk.

"You'll go, I suppose?" he asked the Professor.

"I think so," was Greer's reply.  "I'll cross to-night.  But if I go, I
must first run into the City to see Meyrick," and he glanced at his
watch, exclaiming, "By Jove!  I must be off!"  Then, turning to Antonio,
he ordered a taxi.

"I hope, Mr. Holford," he said, turning to me, "I hope that I've now
convinced you that I'm no impostor, and that I am actually Professor
Ernest Greer in the flesh."

"You have," I admitted; "there are, however, several points which are
not yet clear to me."

"My good friend Kirk, here, will make them clear, I'm sure," he said.
"The only service I beg of you is that of complete and absolute silence.
It was the German's life or mine.  He attacked me murderously with a
knife, and what I did was--God knows!--only in self-defence.  Yet--yet
the public must know nothing.  It is for fear of you, that you might
learn the truth and expose the affair to the Press, that I have lived in
perpetual anxiety, travelling constantly from place to place, in the
hope that you would still regard me as the impostor.  While you believed
that, I had nothing to fear.  My daughter has, indeed, threatened to
commit suicide if the public are told that I killed the man who tried to
steal my secret.  To her, your silence means love and life!"

"Yes, Mr. Holford," declared the girl anxiously; "Leonard does not know
the truth.  If he did, he would surely discard me as the daughter of a
murderer.  Indeed, I could never again hold up my head.  I believe
implicitly in my dear father's version of the affair--yet his enemies
surely would not!  Will you, at least, give me your promise?" she
implored.

I hesitated.  I was not altogether clear upon many points.

"When I have seen my wife and consulted with her I will give you an
answer, Miss Greer," I said.  "I admit that what I have learnt to-day
has held me in surprise and removed many doubts from my mind."

Kirk was explaining how the tiny golden doll, the little charm which had
been discovered after the tragedy, had been traced through the
well-known jeweller in Bond Street who made it, to the Professor as
purchaser; and how Greer had admitted buying it for the purpose of
giving to Ethelwynn to hang upon her bracelet.  But he had lost it on
the previous day.  Therefore it was not a clue to the assassin, as we
had at first suspected.

Just then the grave-eyed Antonio reopened the door, bowing, and
announcing to his master that the motor-cab was at the door.

Thereupon Professor Greer shook my hand, with a parting appeal to me to
preserve silence.

"You will, no doubt, meet your wife ere long, and she will explain much
which is to you still a mystery.  Remember that her devotion to you was
the cause of her absence.  She believed that you were in danger.  That
story was told her to keep her away from you, and thus draw you off the
inquiry in which we feared you might be only too successful.  Adieu, Mr.
Holford!  When I return, in a week's time, I hope you will come and have
a further chat with me.  In the meantime, I can only beg you to forgive
me for being the unwilling means of causing you either horror,
annoyance, or anxiety."

And, with a hurried good-bye to the others, he turned and left the room.

"A point upon which I require elucidation," I said, turning to Kirk, "is
the reason why you and those other men were so inquisitive regarding the
new Eckhardt tyre."

"Why I called to see the tyre was simple enough," he said.  "Max
Leftwich was posing as the inventor of the tyre in question, and thereby
trying to disguise his real profession of German secret agent.  But as I
had come across him in Berlin three years before in the guise of a small
money-lender, I doubted his inventive genius.  I came to you in order to
examine the Eckhardt tyre, and I satisfied myself that Leftwich's tyre
was a mere worthless imitation.  My assistants also came to your garage
for the same purpose, just as I predicted they would.  Leftwich had
opened a depot in Charing Cross Road for the sale of motor accessories,
and the `improved Eckhardt tyre' was one of the inventions he claimed to
be his."

"But you also had a further motive?"  I suggested.

"Certainly, Holford," was his quick reply.  "I confess that I had
watched you for a year, and I felt that I could rely upon you.  I wished
to enlist your services as one of my assistants, and to initiate you
into work for which the Government would pay well.  It would assuredly
have been worth your while to leave your business to the care of your
manager, Mr. Pelham, and take service in the department of which I hold
control.  But, remember, when I asked you to come here, even I was
deceived.  I believed that my friend Greer, with whom I had had a slight
quarrel a few weeks before, was dead.  When I found what had really
occurred, I saw that the only danger lay in your discovering the truth.
Hence all that tangled chain of subterfuges."

"But surely the Professor might, even now, be charged with murder--or at
least with manslaughter!"  I remarked.

"My father may, Mr. Holford, if you do not preserve his terrible
secret!" cried Ethelwynn.  "Upon you alone depends all the future!"

Once again I demanded the truth concerning Mabel and news of her
whereabouts, but all Kirk would tell me was what Greer had already
said--only a promise that we should meet, and that when we did she would
make full and ample explanation.

I returned to Bath Road utterly bewildered, and, seated with Gwen,
related to her the whole facts from the first, just as I have here
recounted them.

She sat staring at me open-mouthed.

"But where is Mabel?" she cried in alarm.  "The Professor and the others
have returned from abroad, yet she is still absent.  Will they accord
you no satisfaction?"

"None!"  I replied with a weary sigh.  "I don't know, after all, whether
to accept what has been related to me, or whether to disbelieve it."

"The fact that the police refused to inquire into your story, Harry,
seems sufficient proof that this man Kirk is a powerful and influential
person.  Indeed, does it not tend to confirm the story that the
Professor did not die, and that he really killed the German in
self-defence?"

I admitted that it did.  And then I made up my mind that, as Kirk would
give me no satisfaction concerning Mabel, I, on my part, would decline
to enter into any bond of secrecy.

My wife was worth far more to me than any international complication.
What was Germany's wrath at being foiled in her dastardly attempt to
obtain the secret of the new steel, to Mabel's honour and her love?

Two lagging days had gone by.

Kershaw Kirk had called in the evening about seven o'clock, but I
refused to see him.  I sent word by Annie that I was out driving a car.

"Tell Mr. Holford to come in and see me the instant he returns.  I must
speak to him at the earliest possible moment," he had said.  And this
was the message which the maid had brought to me when the astute
official of the British Government had left.

Just before ten I entered Kirk's close little den.  He was seated in his
bead slippers and old velvet coat, while behind him stood the grey
parrot, which screeched loudly as Miss Kirk opened the door to admit me.

Seated opposite him, near the fire, was Leonard Langton, pale-faced and
grave.

"Ah, Holford!" cried Kirk, springing from his chair, sharp-eyed and
alert.  "I called on you some time ago.  I wanted to--to make an
announcement to you," he added, with a slight catch in his voice, I
thought.

"Of what?"

He took from his table a long telegram.  I recognised that it was from
the Continent by the fact that it was on green "tape" pasted upon a
form.  Attached to it was a square, dark red label, bearing the words,
"Government telegram: with priority."

"Read that!" he said simply.

CHAPTER THIRTY TWO.

THE PROBLEM SOLVED.

I scanned it through--then held my breath.  It was from Angouleme, in
Central France, and signed by somebody named Croxton, evidently a person
in the secret employ of our Government.  The telegram was a jumble of
cipher figures and letters, but above, written in ink, were their
equivalents in plain English.  The message read:

"Details are as follow: Professor Greer left Paris by the `Rapide' at
9:29 last night for Bordeaux.  He occupied a first-class compartment
alone, and at Poitiers was seen by the _chef du train_ asleep.  Soon
after passing Moussac, towards Angouleme, two men in the adjoining
compartment were startled at hearing three pistol shots in rapid
succession.  They looked out, and saw a man open the carriage door and
leap from the train.  The train was stopped by pulling the
communication-cord, whereon the Professor was found dead on the floor of
the carriage.  His assailant had evidently entered the carriage at
Ruffec, the junction for La Rochelle.  The passengers instituted a
search back along the line towards Moussac, where they found the
murderer lying in a ditch with his neck broken.  Both bodies have been
brought here to Angouleme, and by papers upon the assassin he has been
identified as a German named Henke, lately living at Hillside Cottage,
Epping.  Have had the body photographed, and sending you print for
identification.  Am making arrangements for sending the late Professor's
body to London.  Wire further instructions."

"What does this mean?"  I gasped.

"We know the man Henke," Kirk replied.  "He was a German secret agent,
who has lately been engaged with a number of others in making a complete
survey north of London.  He was brother-in-law to Leftwich.  It was he
who entered the house in Sussex Place to make certain that his relative
was dead, and who, on finding Ethelwynn there, attacked her so savagely,
believing he had killed her.  Finding that he had not, he evidently
followed the Professor, and, alas! avenged Leftwich's death."

"Then the poor Professor is dead?"  I said, amazed.

"Yes," sighed Langton.  "Ethelwynn is now beside herself with grief.  I
have just left her, having broken the dreadful news to her."

"Ah!" exclaimed Kirk, "it's surely a dark and bitter revenge--rendered
all the worse, Holford, by one vivid fact."

"What is that?"

"The fact that Doctor Flynn--who was born in Germany, though of British
parents, and was an intimate friend of Leftwich--suspecting the truth,
told the German's brother-in-law, with this tragic result."

"Then Flynn is to blame for Greer's death!"  I cried.

"Undoubtedly," was Kirk's answer.  "Poor Greer!" he added, "He was an
old and dear friend of mine.  I never suspected that he would be
followed abroad, or I would have gone with him.  Flynn was no doubt
privy to the attempt to be made to secure revenge."

"Where is Flynn?"

"Gone abroad," replied Langton.  "As soon as I told him what Mr. Kirk
had said over the telephone, he packed some of his traps, and, making a
lame excuse that he had to visit some friends in Germany, he drove to
Charing Cross."

I stood gazing at the pair before me, my thoughts too full for mere
words.

Professor Greer's end was, indeed, an unexpected and extraordinary one.

------------------------------------------------------------------------

That night, however, proved full of surprises, for when I returned home
I found Mabel, sweet, eager and happy, anxiously awaiting me.

I noticed she seemed pale, weary and travel-worn, but as she threw
herself into my ready arms with a cry of joy at our reunion, she sobbed
to me to forgive her for doubting me.

"I don't understand you, darling," I said.  "I never doubted you for one
moment."

"Ah!" she sobbed, "you do not know all I've suffered in these long weeks
we have been parted."

"No," I said.  "Tell me, dearest, tell me all."

Then, in broken sentences, smiling now and then through her tears, she
explained how, on receipt of the false telegram, she had at once gone to
Italy, where she was met by Kirk, who told her that I had unfortunately
been accused of the crime of forgery, of which I was innocent, and that
I was in hiding.  He promised, if for the time she concealed her name,
he would take her to me.

They went to Florence, only to find that I was not there.  Thence they
went to Faenza, on the Adriatic side of the Apennines, where she was
handed over to the care of Pietro Merli, who conducted her about the
Continent under the same pretext--always in search of myself, and always
preventing her from sending a message home, for fear, the Italian had
said, that the English police should be placed on the track.  In Vienna,
Kirk again met her, Pietro having returned to England.

Here she met the Professor, whom she had known when a girl at her home
in Hampshire, and who had purposely sent her a note and seen her prior
to conniving at the trick by which she was enticed abroad and kept apart
from me.  She had, in turn, been introduced to Sir Mark Edwards, who
came to Vienna to purchase the secret of the new process, and had
accompanied them one evening to the opera.

From Vienna my dear wife was induced to travel alone to Moscow, where
for the past fortnight she had been awaiting news of me promised by the
Professor, who had all along supplied her with funds.  Three days
before, however, she had received a telegram from Kirk, telling her that
the charge against me was withdrawn, and that I had returned home.
Then, of course, she had not lost an instant in returning to my side.

During my absence at Kirk's house Gwen had been telling her sister the
whole remarkable truth.  Therefore, when my wife had concluded her
story, her head fell upon my shoulder, and in tears she begged
forgiveness for doubting me, a fault which, in those circumstances, I
freely forgave--as you may quite well imagine.

Is there any need to say more?

Need I tell you that Mabel and myself stood beside the grave and watched
the burial of poor Professor Greer at St. Peter's, near Broadstairs?

Need I tell you, either, how, just a year later, Ethelwynn, who had
inherited the great fortune accruing from her father's discoveries, was
married to Leonard Langton, both my wife and myself being honoured
guests at the wedding?

Flynn has not been heard of since; but Antonio is still all-powerful at
the pretty house Langton has taken in Hill Street, and on more than one
occasion Mabel and I have been guests at the bright, breezy seaside
house overlooking the Goodwins, beyond Broadstairs.

Leonard Langton and Ethelwynn are extremely happy.  Yet I verily believe
that Mabel and myself are even still happier, for I cannot help thinking
that our enforced separation has rendered the joys of our lives the
sweeter, and has proved our mutual trust and love.

Kershaw Kirk is still travelling hither and thither, ever active as
secret agent of the British Government, and ever prone to ask the advice
of his feathered pet.

As for myself, I still carry on my garage in Chiswick, a business which,
I am glad to say, is rapidly extending, though I confess it very nearly
came to ruin in those dark, breathless days when I was seeking a
solution of the remarkable problem of "The Red Room."

The End.