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                              THE MYSTERY
                                 OF THE
                             FIFTEEN SOUNDS


                             By Van Powell

                   [Illustration: Title page graphic]

                    The Goldsmith Publishing Company
                                CHICAGO

                           Copyright 1937 by
                    The Goldsmith Publishing Company
              MANUFACTURED IN THE UNITED STATES OF AMERICA




                                FOREWORD


"_No wonder I'm blue," Roger told his father, "You're packing to head a
museum expedition into the heart of Borneo._ You'll _have thrills_."

"_Probably I will get my sort of excitement in plenty, Roger. It won't
be what you are always dreaming about--the 'good old days' of Pirates
and Cowboys and Stage-Coach Bandits._"

_"No," Roger agreed, "the real thrills are all gone. But you can go on
an expedition, instead of having school and_----"

"_There will be vacation time--baseball_----"

"_But I want real excitement. I'd like to be a Modern Pioneer. You are
one, going off to Borneo for the museum just the way Columbus set out
for Queen Isabella._"

_His father looked up._

"_You can be a Modern Pioneer. I will show you a House of Mystery, and
once you step into its door you are in a land where there are more
exciting activities packed into one day than you could get being a
combination cow-hand, bad man, pirate and pony express rider. You may
not be able to convoy an ox-team across a prairie, carry a squirrel gun
and stand off scalping Sioux; but you will help battle against Pirate
Fire, and Bad Man Erosion, and Bandit Microbe._"

"_You mean--work in cousin Grover's research lab?_"

_That was it, he found. And under the brilliant training of his older
cousin, as he came to be the supply clerk and learned more about the
work of the active place, Roger saw how truly his father had spoken._

_There was fun, and mystery, and excitement, even in the work. Also,
there was the feeling of being a Modern Pioneer, one who belonged to the
band that had substituted electricity and wings for ox-wagon and
candles, who gave the world instead of the pony rider carrying news, the
radio and radio-telephone. Science was the Modern Pioneer._

_Where their forefathers sought new borderlands, these modern
way-showers explore the stratosphere. As their trail-blazing ancestors
fought Indians and hardship and poor crops, these men battle against
disease germs, and soil erosion, and eye-straining light and every other
detriment to safer, happier existence._

_As great as the feat of Columbus, Roger found the announcement that a
cure had been found for a terrible disease._

_On a par with Daniel Boone's fame was the renown of the research worker
who extended the range of compact radio receivers._

_In such privately owned laboratories as that of his cousin, Grover
Brown, and in those associated with universities and colleges and other
institutions, the work of the Modern Pioneers went on._

_They loved it, found adventure in it, and joy of achievement._

_Not always was there the sort of mystery usually read about in
detective stories; but when such problems did come up, Roger realized
how the equipment of scientific research could be a useful aid to the
clever deductive brain in solving the puzzle._

_It is to show how much of adventure and thrill, excitement and romance
can hide behind electrical transformers and tubes of germs, bags of
sodium carbonate and humming motors that this experience of a boy in a
scientific research laboratory is offered. Perhaps some boy, who has
almost decided that the only "real" life involves guns and "rackets,"
will be shown how the useful life of the fellow who fights for humanity
and not against it brings more thrill and joy and contentment than any
of the risky, falsely stimulating adventures that only lead to
discredit, sorrow and punishment._

                                                              Van Powell


                                  NOTE

Names used in this story are purely fictitious and if any name is like
that of a real person it is coincidence and no libel or aspersion on
character is intended or implied. However, every scientific device,
process and theory herein is based on electrical, chemical and other
data of developed apparatus and procedure or on theories so far
perfected as to be acceptable to Science.




                                Contents


                                                                    PAGE
  Foreword                                                             9
  CHAPTERS
  1. "Them Mouses Is Extraverted!"                                    17
  2. A Creeping Thing!                                                23
  3. A "Sound" Clue                                                   29
  4. An Electrical Trap                                               38
  5. What Electricity Could Not Catch                                 44
  6. A Weird Story                                                    52
  7. Science to the Rescue                                            60
  8. Basketball and Brains                                            66
  9. The Voice in the Silence                                         72
  10. A Defeat for Science!                                           78
  11. A Puzzling Thump                                                84
  12. Detective Roger                                                 90
  13. Scientist Roger                                                 97
  14. Captive Roger                                                  102
  15. In the Lamasery                                                107
  16. The Image Speaks                                               113
  17. Black Silence                                                  117
  18. A Letter Roger Had Not Sent                                    121
  19. Disquieting Deductions                                         127
  20. Ghost Voices                                                   131
  21. Tragedy!                                                       137
  22. What Happened to the Eye of Om                                 143
  23. The Acid Test                                                  147
  24. An Impossible Camera "Shot"                                    151
  25. Score One for the Mystery Wizard                               154
  26. Roger Lists His Clues                                          159
  27. A "Thermal" Trick                                              166
  28. The Fuse                                                       172
  29. A Surprising Capture                                           176
  30. The Voiceless Warning                                          184
  31. The Hidden Menace                                              188
  32. Science Fights Craft                                           191
  33. A New Suspicion                                                195
  34. Tragedy Strikes Again                                          201
  35. The Stalking Terror                                            206
  36. A Law of Nature                                                212
  37. Revelation!                                                    217
  38. The Vigil                                                      223
  39. The Ape and the Kangaroo                                       227
  40. The Mystery Wizard's Solution                                  235
  41. Man and Beast                                                  241
  42. Closing Time                                                   246




                               Chapter 1
                     "THEM MOUSES IS EXTRAVERTED!"


Something was wrong at the laboratory! Ringing bells, long before dawn,
awakened Roger Brown.

Dazed at first, he became alert as a strange, cold foreboding made him
leap out of bed.

"Just the telephone," his thirty year old cousin, head of the
laboratory, called from his room beyond the adjoining bath. Roger, who
was already on his way to the downstairs library of his cousin's home,
paused.

"No!" Well built and athletic, sharp-eyed, keen minded, a worthy student
under his brilliant scientific cousin, Roger spoke earnestly, "It wasn't
just the protective beam system, or just the fire alarm, either. Grover,
it was _both_!"

"Impossible! Why have they stopped ringing?" Tying his robe cord, the
older cousin followed Roger. He knew that "Ear Detective's" reputation
for reading sounds, even if his own incisive reasoning made him feel
that this time Roger had been too drowsy to live up to his nickname.

Just the same, he followed.

"As long as the beam was broken," he insisted, "The bells ought to
continue to ring. I think your fame as a sound interpreter is done."

Roger did not try to defend himself.

"It was probably a wrong number on the telephone." Grover was five steps
behind his younger relative, "If you are so sure it was our alarm
system, especially both bells, why aren't you dressing to rush to the
lab?"

"I'm getting down to be ready when Tip calls."

Potiphar Potts, nicknamed Tip, was handy man at the scientific research
plant. He slept there. In a moment Roger expected to have him call up to
report the reason for the alarm.

"You will never hold your reputation now." Grover turned at the library
door as Roger, inside, stared, baffled, at the annunciator panel.

The reputation his cousin spoke about had come when a chemist, sent to
them to help the laboratory develop a new series of dyes for a textile
mill, had begun to "hear things." Deaf, wearing an Amplivox, composed of
a chest microphone, batteries and an ear piece, the man had been nearly
crazed by a persecuting, accusing voice picked up, it seemed, by his
device. Roger, by identifying an odd click he got in a makeshift
imitation Amplivox set, gave Grover the clue through which a revengeful
enemy who had sought to terrify the man had been discovered. As The Ear
Detective, Roger, who was in charge of the laboratory stock-room, had
really been the means of solving the mystery.

"I know I heard the laboratory bells," Roger insisted.

"But the lights on our tell-tale are not lit."

"I can't help it. Both the fire alarm bell and the system that warns us
if anybody enters----"

"But Potts has not called up, either. Go back to bed."

Grover turned to leave the room. Roger, who was staying with his cousin
while his own father headed an exploring expedition into Borneo for a
museum, knew that his ears had not betrayed him.

His cousin, several years before, had secured capital with which to
start a scientific research laboratory for the use of small companies
unable to maintain equipment and an expensive staff.

Every form of research, electrical, chemical, industrial, and in one
instance medical, had been successfully undertaken.

The "lab" prospered, and enjoyed a reputation for scientific and human
thoroughness and dependability.

Priceless secrets, formulae, data and results were always in the
laboratory, and its owner had devised seemingly perfect methods for
safeguarding the secrets which rivals, or competing firms, might covet.
A completed series of experiments to find a synthetic substitute for
camphor gum, an industrial formula almost beyond price, was reposing in
the safe on this early morning of Spring.

The safeguards comprised two:

There was a series of light-beams, interconnected with microphones and
tiny speed cameras, at every possible entrance. Any broken beam, telling
of wrongful entry, set off a laboratory bell in the room where Potts
slept; and it also was wired to ring a bell at the owner's home; and on
a panel, numbered lights would show, by the one that glowed, which
entrance had been used.

To protect the laboratory from fire, and warn of its existence, a bell
of a higher tone with a thermostat connection in the laboratory, in each
section, would give warning; and if the blaze was in the cellar, a green
bulb would glow; if in the main floor, a red bulb, and for the upper
section a blue bulb would be lit.

Naturally, Grover felt that his younger cousin had mistaken the sound
that had awakened both.

Roger, still feeling his weird and unexplainable sense of hidden danger,
picked up the telephone.

The laboratory, when he dialed repeatedly and waited long, did not
respond. Tip, trusted, loyal, paid extra salary because he was counted
on not to leave the mechanical devices to give the sole protection,
should have answered his extension telephone.

"I tell you there is something wrong," insisted Roger.

His cousin, partly convinced, taking on some of Roger's concern, began
to dress.

Just as he came down Roger knotted his tie.

In the car kept handy in the garage, they drove the several blocks to
the two-story building.

Before they got near it, Grover put on speed.

Fire sirens and the scream of the warning signal on a police car made
both cousins wonder what terrible situation they might face.

Had some one, entering the laboratory, set off the first alarm as fire
broke out? Had Potts, fighting either fire or intruder, been rendered
incapable of responding to their telephone call?

"Oh, I hope nothing has happened to Tip."

Roger was very fond of the dull-witted, but dependable man, almost an
Albino with his sandy hair and light eyes, who loved to use big words
whether they fitted his idea or not, and who helped in the many
mechanical, photographic and other activities involved in their work.

The car, racing forward, turned into the proper street and they saw fire
apparatus gathering in front of the building. Roger, as the car slowed,
leaped out, crouching and running to avoid being thrown down by the
momentum.

"Don't break in!" he shouted to firemen, "Our protective gas will
prevent damage--and water would ruin our electrical things."

The company captain paused as he saw, behind the youthful caller, the
taller laboratory owner striding forward.

His men, with a battering ram, delayed.

The helmeted men, some with axes, others with scaling ladders, hose, or
the rubber covers used by the emergency squad from the Fire
Underwriters, paused.

"What-da-ya mean, nothing more won't burn?" growled a policeman from the
patrol car standing nearby.

His finger pointed toward the glass panel of the main door.

Roger, looking in, saw the curious orange glow and the weirdly
bluish-violet splaying out across the office from the inner spaces.

"Who--what set off the flouroscope and the X-rays?" he gasped, while
Grover reassured the gathered people.

Unobtrusively setting one foot well to the side on the top step, so that
his toe, pressed forward, found the small protecting pin, he unlocked
the door, careful to keep the knob turned toward the left, instead of in
the natural hand-turn to the right.

That, Roger knew, cut out that particular light-beam system, so that
they could enter without altering the present status of the tell-tale
panel inside that would reveal where entry had been made, and by which
magnetized plate the marauder would be held in trying to escape.

They rushed in. His first rush took Roger to the panel.

Not a bulb glowed! He stared, unable to accept the story it
told--somebody had set off every light-beam-trip! That put out the
lights.

Not one of the row connected-in with the magnetized plates was lit,
either, and yet no living person should have walked or crept or climbed
away through door, window, coal-chute or other exit without getting
caught. But Roger did not pause. He ran to Tip's room.

Tip, tied tightly to a bedpost, his lips taped shut, his eyes rolling as
he sweated in his frantic effort to escape, saw him.

Roger first took the tape off as gently as haste allowed.

Just as soon as he was able to speak, Tip gasped:

"Tell Grover them mouses ain't is."

"Ain't _is?_----"

He knew that Potts used queer phrases, trying to fit big words in, and
this might be his way of leading up to some puzzling declaration.

"What happened? Stop being smart, and tell me!" ordered Roger.

"If mouses is here, you say they _is_ here?"

"Well?----"

"They ain't is."

"Gone?" Roger stared, "The white rats. Gone?"

"They done extraverted."

Roger had to study that out. He knew that the psychological word was
used by analysts of human minds to indicate people whose outlook on life
was normal, while introverts were shy, timid people who were afraid of
life. "Extraverted" must mean that the animals had turned outward toward
the world--run away, or escaped.

"But those white rats--Doctor Ryder's--were in a cage with a trap door
on top, and they'd been inoculated with cultures of a spinal disease,"
cried Roger. "How do you know?"

"I was up lookin' at 'em, and somethin' with a hand like a ham hit me
back of the ears, and when I come to, tied, them rats was evacuated. I
was drug down here by a ape and tied. An' there was somethin' else I
didn't get a look at, behind the ape."

Was the man crazed? It worried Roger.

But a call from Grover, upstairs, quickly told him that Potts had not
been talking wildly.

"Roger," called his cousin, "The white rats' cage is empty!"




                               Chapter 2
                           A CREEPING THING!


It took Roger a moment only to realize the enormous danger that was
behind the loss of those inoculated rats.

When Doctor Ryder had been allotted space in which to conduct his
experiments to see if he could perfect a cure for a horribly deadly
spinal affliction, he had decided to experiment, first, on animals.

Such experiments had been gotten under way the night before.

The rats, inoculated, were carriers of the deadly germs. If some
ignorant person had taken them, and the public was not warned to be
careful, anything might happen!

One of Grover's constantly repeated axioms about laboratory work was:

"Do the first thing first!"

All life, the scientific student always had insisted, was like the
chemical compounds they handled. No matter what the problem might be, no
matter how it looked, it could be analyzed the way compounds would be
analyzed, the elements could be isolated, and the base--the guide to the
whole condition--could be known. Sodium, a metal, very unstable,
combined with chlorine, a gas, turned into sodium chloride, and that was
a salt--common table salt, in fact. Yet the restrainer used in
photography, a dissolved salt, was sodium bromide, another gas and the
metal, and to find out what a compound held, one had to separate all
parts by test and find the base or original element.

But first, one must do the first thing--and in this situation Roger knew
that the first thing was to get busy on the telephone.

White rats had been inoculated with dangerous germs. A bite from such an
animal was ten times more terrible than that of a plain rat, poisonous
though that would be. Therefore, if those inoculated animals were now
missing, Grover, up where their cage had been, would know it already;
but the public, exposed to possible contamination, must be warned.

Roger plugged in the upstairs telephone so that the policeman could
reach his headquarters and start a widespread search of all cars on the
roads, all suspicious people carrying sacks or other possible packages
or cases that could hide the rats. The Health Department and news and
radio agencies must be asked to broadcast public warnings. And the owner
of the rats, Doctor Ryder, should be called.

Therefore, when Roger went upstairs, his report made his cousin nod
approvingly. Roger had done all he could to avert danger if the rats had
been taken ignorantly by some idiot who might let one or more escape and
spread disease germs.

With his story told, Potts was busy doing what Grover had ordered as one
way to secure clues: a motion picture camera using non-flam film,
flashbulbs of the latest type, tripod for time exposing, and both
wide-angle and micrometric lenses, to give large views of big spaces or
vastly magnified details of practically invisible things, formed the kit
that the handy man worked with.

Because he had used his wit Grover had no orders for Roger as the
firemen, police and officers departed.

Nothing could be done until Potts developed his "takes" so they could be
run in the laboratory screening-room.

Grover, in his small, private "thinking den," would want to be left to
think out and separate all the mysteries, so that he could get to the
heart of the affair and thus decide what to do about it.

Alone, wide-awake, with the dawn just beginning to lighten the skylight
in the roof over his stock-room, Roger stood thinking.

He knew that if the small, partitioned space set aside for Doctor Ryder
had held clues, Grover would have told him.

The germs supposed to have been injected into rats the night before
could not have produced much effect that past night. The doctor had not
felt that he had to observe, personally, as he would have done later.

Instead, automatic "observers" had been set up.

Inside the empty cage, a dictagraph microphone showed, fixed to the
glass inside the cage top. That, Roger knew, led to a device like the
seismograph which registers earthquake tremors. Its purpose was to show,
by the vibration of a pen across a moving tape, when the rats developed
any unusual excitement or stress, which was not expected but was
provided for in that way.

A camera of the moving picture type, but set to snap one take at minute
intervals, would check also; and if the seismograph got to zig-zagging
sharply, it would make contact on one side with a relay, and throw on
the "continuous" mechanism of the marvelous camera.

To discover by calculating how much of the tape had been unreeled when
something had stopped it, was easy; and in that way Roger knew the time
that the mechanism had stopped, although he did not dare fix that as the
time the rats had vanished, because the tape had started at five in the
afternoon, and had unreeled to the point to show that it had stopped at
four in the morning; but the alarm had not sounded until half an hour or
so later.

The tape showed excited swerves of the recording stylus, but not
apparently enough to start the continuous takes, because Grover had left
the magazine as it was until Potts should be ready to develop all prints
at one time.

With his snapshots and time exposures of wide-angles of windows, doors,
floors, air-conditioning intake, exhaust, cellar openings and floors,
and his micrometric detail close-ups of parts of all these, Potts went
to the dark-room adjoining Roger's stock-room. The film he had taken
would fill all tanks, so he left the other till later.

The authorities had been warned; and nothing more could be done.

Roger, as the sun rose, telephoned for light breakfast to be sent from a
nearby restaurant, taking Potts his share in the dark-room.

As he ate, Roger tried to bring some sense into the baffling set of
conditions:

The white rats, in their cage, with the observation apparatus and chart
with notations, should have been recognized by anybody who could see and
who could read, as dangerous to handle, much more to remove.

With the protecting system set, it should have been impossible to enter,
at all, and more impossible to get out.

Yet the rats had not by any magic been evaporated into thin air.

Furthermore, Roger mused, why had the fluoroscope and X-ray machinery
been put into operation?

The entire situation seemed to be too bizarre to be true: more than all
the rest, the mad story of Potts that he had felt a hand as "big as a
ham," hit him before he had lost his senses!

Nothing fitted anything else.

Doctor Ryder, arriving, was as much a contrast to cold, unexcited Grover
as could be imagined. He sputtered his fears for the public, his dismay
that this should have brought discredit on the laboratory that had been
known to safeguard its precious data.

Roger, watching the pudgy, stout little germ experimenter who excitedly
mixed wild theories with wilder plans of procedure, thought to himself
that if anybody or anything would upset his cousin, the man's emotional
excitement would be the thing.

Grover was not stirred out of his quiet manner.

The staff began to arrive. They had all seen in newspapers or had heard
by radio the warnings and the brief story of the lost rats.

Mr. Millman, the electrical engineer, asked immediately of Dr. Ryder:
"Have you any enemies?"

The experimenter thought that he might have antagonists among the
scientists who disagreed with his theories; but they would not be men
who would endanger the public for so small a revenge as could come from
criticism of his laxness in not watching his experiment more closely.

Mr. Ellison, the laboratory's electrical research specialist who worked
with Mr. Millman, agreed; and so did the bio-chemist, Mr. Zendt; the
analytical chemist, Mr. Hope, and Grover.

They were discussing the many contradictory and unexplainable points
when Potts called, from the darkroom:

"Hi, Rog'--come quick!"

As soon as his eyes were accustomed to the dull rosy glow after he
passed the light-trap, Roger saw Tip clipping non-flam film positives to
drying drums.

"What have you got, Tip?"

"Look!"

Potts snapped a strip in place in a vision tunnel: Roger applied his eye
to the lens, and saw, enlarged on the viewing-plate, what appeared to be
the edge of a cellar step. With side-lighting, magnified ridges and
depressions in dust looked like a range of hills and vales.

"It was a snake!"

"A--did you say 'snake'?" Roger gasped, "How do you get that?"

Potts changed films under Roger's gaze; an enlarged wide-angle of
several steps was before his eyes, and the snake-slide of some body that
had dragged across just the step-edges, and had made no track of hand or
foot on the level of the steps showed!

"It certainly looks like something that creeps, Tip."

"Well, a snake creeps. A snake! What else?"




                               Chapter 3
                             A "SOUND" CLUE


Without waiting for the gelatin to harden, Roger summoned the staff and
his cousin to the screening room. As soon as they had set their wrist
watches with the observatory time signals, a routine part of the staff's
accuracy, they joined him.

He had the tender emulsion-covered celluloid threaded from the top
magazine through film gate and take-up sprockets down to the lower
magazine of the projector. In the small, compact theatre, with its
platform for lecture and demonstration procedure, its large screen, easy
chairs, loud speakers and apparatus, he showed Grover and the men what
caused him to agree with Tip.

"It almost has to be a snake," Roger declared.

No other than a creeping thing could drag over a step edge. Four footed
creatures, he explained, did not disturb dust at the point indicated in
close-up and wide-angle pictures, greatly enlarged by the projector.

The chief electrical specialist, Mr. Ellison, agreed. "It ends the
mystery. A snake ate the rats."

"Then there won't be any disease epidemic," Doctor Ryder was much
relieved, "It will crawl somewhere and the germs may destroy the
reptile." To this Mr. Millman, electrical engineer; Mr. Zendt,
bio-chemist; Mr. Hope, their analyst, and others, agreed.

Roger saw that his cousin reserved opinion. But routine had to go
forward, and the staff men separated. Zendt went to resume experiments
in the search for a dye of a certain desired shade and quality: the two
electrical men were busy developing means to find a better way to
insulate high-tension cable for carrying electricity from generators to
distributing stations in small communities; the others had equally
absorbing work in progress.

Grover, busy examining each picture projected and held on the screen
without danger of the "cold" light igniting the protected film, gave
Roger a dozen cellar views around the coal-chute to enlarge.

"Make ten-by-twelve bromide enlargement prints," he ordered.

Roger, although it seemed impossible that anyone could have moved the
stiff rusted bolt inside the trapdoor of the coal chute, a trap that
lifted up and out onto the street, said no word of objection.

He felt that Grover would find nothing in the enlargements.

Expertly he adjusted paper on the camera-stand, extended the bellows to
secure most perfect focus, made his exposures, developed, and fixed the
large prints, and took them to his cousin's own den.

"As I expected--nothing!" he reported.

"No abrasions of the bolt, or edge of the trap?"

"You mean, where someone inserted a 'jimmy' to shove back the bolt?"

Grover nodded.

"Not a thing shows." Roger asserted. His cousin did not accept his
statement; but his disappointed eyes told Roger that the examination he
had made during developing work had been accurate, thorough, and had led
to a correct decision.

They were at a standstill. Calls to the zoo, brought from its curator
the declaration that no snake was absent from its cage, that no one of
his keepers had tried to "train" snakes--as the laboratory head had
half-laughingly suggested.

As he left the screening room, Roger met Potts.

"Tip," he hailed, "Did you get anything on the 'sound' film in the
one-snap-a-minute camera?"

"The one that took pictures of them mouses?"

"The one by the rats' cage--yes."

"You know about sound, Rog'. It ain't just a lot of single pictures."
Potts wanted to air his knowledge. "Sound is a maintained concession of
peaks an' valleys on the sound track."

"You always will use a .44 caliber word when a BB. size would hit what
you aim at and not blow your idea to bits, Tip. You mean that sound is a
'sustained succession'--I know that. And single frames, if they showed
any sound impression at all, would give little pops."

"So I didn't bother."

"But, Tip! There was a lot of wild zig-zag marking on the tape in the
seismograph-like recorder; and it seemed as though the 'continuous'
taking lever had been shifted before he--it--whatever was there, stopped
the whole business by breaking off the wiring."

"We can try."

When they had developed the negative, made a print and fixed and washed
it, Roger threaded the fifteen frames of continuous shots in place and
projected with the speakers cut in.

Then he rushed to get Grover. The staff too!

He had a clue.

As nearly as he could have described the brief sound made and amplified
with transformer-coupled, matched metal audio tubes of the most perfect
type giving the speakers power, they had picked up a sound of hot grease
sputtering, hissing and clicking, as it does if sausage is fried
rapidly.

"Come on, Ear Detective," chaffed Mr. Millman, "Who was frizzling
sausages on the cage full of inoculated rats, so that the mike inside
picked it up and took it on to the sound film?"

"That's not sausage frying," exclaimed the biochemist, "Someone had
steam up and the mike picked up the sound the radiator valve made as air
was expelled and steam arrived to close it spasmodically."

"A microphone, inside of a glass cage top?" mocked Mr. Ellison. "How
could a valve on a radiator across the room make all that noise?"

"Let the Ear Detective explain it," urged Mr. Hope.

They all turned to Roger. He shook his head.

"It does sound most like the snick-snap, and sizzle, of sausage," he
admitted, "But----"

"It's a snake, I say," Potts defended his theory; "a snake, with hissing
and his scales rattling on the glass when he was crawling up to dig his
head in and grab breakfast."

"What's your idea, Grover?" asked Mr. Hope.

"Sounds as much like a snake as anything I can imagine, Sam."

"So say I," agreed Mr. Ellison.

"Are we right, interpreter?" Potts got the correct word, for once.

Roger hesitated. Not that he cared if he lost his reputation as a young
person able to read correctly what his sensitive ears caught; Roger was
not vain or self-satisfied. He was not the sort to make a statement just
to hold up his reputation.

In some ways the sound might be such as a snake, with its hide striking
or rubbing, as it hissed, could make; but, again, a lizard might make
that sound--or a dog, scratching on a window.

He stood up, excited for the moment.

"_Claws on glass!_"

His sharp cry died into silence. They all considered it.

"A snake ain't got pedicular exuberances," objected Potts.

"Pedal protuberances, eh, Tip?" chuckled Mr. Hope, "What do you say,
Grover?"

As Roger looked toward his cousin he saw what surprised him most of all
that had so far happened.

Never in his stay at home or laboratory, intimately close to the
scientifically brilliant, but poised, cousin, had Roger seen him lose
his calm.

Now, Grover stood up, and in his eyes was the same sort of light of
satisfaction and triumph that a boy would show when he had successfully
smuggled in and hidden mother's birthday present.

"Roger is absolutely right!"

"Claws on glass? A big dog?" asked Mr. Zendt.

"Remember the cellar step clue."

"A lizard?" Mr. Ellison suggested.

"Remember Tip's statement about how he was knocked senseless."

"Oh--a man with a--a what?" Mr. Millman was not so confident of his
deductive ability. He paused.

"I will leave you to work it out," Grover beckoned to Roger; "I must run
out to the zoo." He was as eager and elated as a boy with a new
football.

He beckoned to Roger who followed as his cousin got his hat.

"I want you to go to all the newspaper offices. Take a taxi. Get back
issues for the past two weeks, maybe you'd better get them for three
weeks back."

"You know?----"

"I have two theories. I want to make sure which is right."

"Do you really think I got the right meaning out of the hisses?"

"Precisely the correct meaning."

"But it doesn't tell _me_ anything, cousin Grover."

"Use my formula. Dig past appearances that can be falsified, to the
truth. Marshal your facts, test each one, eliminate the impossible and
what you have left is the truth."

Telephoning to summon a taxi for Roger, the laboratory head was busy for
a moment. Roger tried to employ the method just named.

Youth, inexperience in doing such consecutive and eliminative thinking,
he knew, hampered him. With a mind trained, through solving chemical,
electrical and other industrial experimental difficulties, Grover's
clever mind had skipped many of the links that Roger, slowly, had to
take up and examine.

He was in the taxi, with bundles of back issues of the city papers, on
his way back, and still his mind was a maze of unfitted details.

In the office, combing the papers for notes about snakes, or any other
escaped reptile--he had to keep in mind that trail on the edge of the
steps alone!--he got nowhere.

No news showed up about lost, stolen or escaped animals or any form of
brute or reptile.

Grover, he saw, had returned, and was not joyful.

"One theory went to smash," he said, "I verified your sound--claws on
glass was the right deduction. But--that doesn't bring what I want."

"What do you want?" asked Roger, eagerly.

"To capture the culprit."

"Won't the police?----"

"We have no justification for calling them in. Nothing has been stolen.
Nothing has been harmed."

"The rats----the menace to the public!"

"Roger, you haven't _studied_ those films Potts took."

Roger got them at once, projected, one at a time, examining the screen
images carefully. The cellar views, only proving that some object left
no other trace of progress than scraped dust on step-edges, he
considered and discarded.

Those taken by windows, doors, intakes and outlets of the
air-conditioning, and gas-exhausting roof, cellar and wall orifices gave
no revealing clues.

When he got to the wide-angles of the lower floor and stairway, and
found no reward for his long scrutiny, Roger was baffled.

Only the micrometric enlarged snaps and one time-exposure near the X-ray
devices remained. He considered them ruefully. They gave no foreground
evidence to help him.

Roger, with defeat creeping over his feelings, was about to give up.

He was fair, he told himself, when it came to interpreting sounds, but
at the more important quality of being able to connect the clue with
everything else, he was "stumped."

What could those enlarged views hide from him?

The walls, with racks of test-tubes, some containing chemical solutions,
others holding cultures of various forms of growth that Mr. Zendt had
accumulated or was studying, told him----

He stared, bent closer, climbed up on a chair close to the screen!

After two minutes of close scrutiny, he jumped to the floor, and raced
to find Grover.

"Just by chance, in taking the micro-lens pictures," he gasped out, "Tip
got in some of the test-tubes. Is that what you saw?"

Grover, smiling, agreed. "What did it tell you?"

"I arranged those racks yesterday. I have got a good memory."

"I knew both those facts," Grover admitted, "and I, too, helped in
revising our arrangement of the racks. Go on!"

"The tubes that held the culture of the spinal disease germs--so
dangerous that they had been delivered, personally, by the medical
center bacteriologist, had _blue_ labels!"

"You are 'warm' as the hide-and-seek game puts it."

"I saw Doctor Ryder take them up, in his surgeon's clothes to prevent
infection."

"So did I." Grover acknowledged the fact.

"He actually took two tubes that must have had the right labels because
he would have seen what they were marked."

"Labels can be soaked off and transposed from one tube to another,
Roger."

"I think that happened. He took them, went up, and we both saw him use
the hypodermic needle."

"But--" Roger could hardly restrain his thrill at having made as clever
a discovery as the coming one:

"Those two tubes--full!--are in back of others, right now. Not the two
empty ones he incinerated to be sure the germs were all destroyed."

"They are? How did you discover it?"

Roger told him: "Our chemical labels that are a green, photograph a
darkish gray; and our culture labels, that are a buff, photograph
lighter, but still grayer than white paper. The poisons are labeled red
and come out in a picture almost black.

"_But blue except very dark shades, will photograph nearly white!_ And
those two labels, hidden in a dark corner, show up in the picture where
they might not be noticed in the rack."

"Can you go further and say why no culture was allowed to be given,
although the inoculator evidently thought his serum was genuine?"

"Whoever was going to take the rats, did not want them to be dangerous
to him."

"Very nicely argued out, Roger," his cousin complimented him. "Now, we
must find a way to draw that criminal who trains animals to do his work,
into the open where police can get him."




                               Chapter 4
                           AN ELECTRICAL TRAP


Startling though Grover's statement that a man trained animals to be
criminals was, it gave Roger the one link to build what he knew into a
chain.

Trained animals! That fitted in with claws on glass and made the rest of
the puzzle fall into place.

To Roger, it seemed clear that a clever animal trainer could teach his
beasts to obey criminally intended orders just as well as make them do
the ordinary tricks.

What animal, he mused, would fit the conditions?

A monkey came to mind as the logical sort.

First of all, it was the one animal able to climb down a rope from the
skylight on the roof, which it could have reached by being taken up the
fire-escape on a candy factory next door, one story higher than Grover's
research laboratory.

Coming down in that fashion, it could have been made to do a trick
taught for the purpose--take the white rats, put them in a sack, and fix
it to the rope--or the sack could already be at the end of the rope.
Then, unaware that it had set off an alarm, it could have wandered
about, doing such tricks as getting into the light beams, pulling the
switch to "on" for the X-ray and the other electrical devices.

Such an ape, too, with its master joining it during the time it wandered
about, could have invaded Tip's room, striking him with a huge paw,
because it would be an ape; no smaller monkey could have reached down
into the rats' cage.

"How will you trap him?" Roger asked.

When his cousin outlined his plan, Roger was animated.

"It might work," he exclaimed, "He will turn out to be the one who
brought the white rats. They were trained, too, maybe."

"I wondered that you did not see why I bought back issues of the
newspapers," Grover told him, "I had one idea that the thing might have
been done by some zoo keeper; but the more possible notion was that some
vaudeville act had trained animals. Now we do not need to comb through
the advertisements of the theatre section. We know, by logical
deduction, that we would find it."

Roger, and Potts, carrying out instructions about which they said
nothing to any member of the staff, assembled a mass of materials,
apparatus and paraphernalia.

There were microphones; and they employed the laboratory's device for
producing infra-red rays, as well as a number of small cameras for
taking motion pictures which Potts secured; to each one they applied a
shutter-trip suggested by Grover, that would operate when a light-beam
of the infra-red variety might be unknowingly broken by an intruder.

Other parts, and wiring by the yard, they connected up.

"But I don't understand it," Potts argued as they worked. "It's all
right to say a monkey climbed in through the skylight way; but how does
that fit the snake-trail up the stairway?"

"I asked about that," Roger told him, "Cousin Grover was more in a
joking humor than I ever saw him, and he said I'd done so well, he would
leave that for me to work out, too."

"Did you?"

"I think so, Tip. How's this? Monkey comes in. No alarm on the skylight,
because the magnetic plate under it would be 'on' all night and would
have caught anybody--anything but a monkey able to jump at a command
while it swung clear--or the man above swung it."

"So far, so good." Potts waited expectantly.

"The ape wandered around, until it heard a call it recognized from
outside, on the street. It was trained to open bolts, and the only other
bolt that wouldn't have a camera equipment and electric plate was our
coal chute, that had the Chief stumped how to fix it."

"And why would he have to go down there?"

"To let in his mate--another beast."

"And what was it?"

"Well, what could leave a snake trail?"

"A boa-constrictor, or one of them bushmasters out of Australia?"

"What else--out of Australia?"

Potiphar stared, thinking hard.

"I don't know."

"Something that hops, and balances with its tail."

"A--you mean a--kangaroo?"

Roger chuckled, nodding.

"But why did they go to all that trouble, when a man could of swarmed
down a rope, and got the rats?"

"If he'd got caught--not knowing everything about the inside of our lab,
maybe," Roger responded, "He'd go to jail. But if we got a kangaroo, or
an ape, the animal trainer could know it and have an ad. in next day's
papers, get back his animal that couldn't tell what it was there for,
and----"

"Well, what _was_ it here for? What made all that compulsatory?"

"The motive made it compulsory, Tip."

"You didn't tell me about any motive. Or how all this wire and stuff
will catch anything when we don't know anything will come tonight, like
you hint at."

"The motive, Cousin Grover thinks, is to get into our safe, for our data
and formula for synthetic camphor."

"Well, come to think--one nation practically controls the camphor gum
output, and if they want to raise the price----"

"Or forbid export to any other country, in war----"

"I can see how much it would be worth to have what we developed for one
client. Maybe some foreign nation wants the secret." Tip was alert. His
pale blue eyes and almost albino-white hair made him seem, usually,
washed-out and not very bright. But with this thrilling possibility of
intrigue and excitement brewing, he was as alert and intelligent as
anyone could be.

"We don't know. But Cousin Grover thinks he will draw them on, and he
publishes in the evening papers quite a write-up about the completion of
the data. A friend, a newspaper fellow, will help us get it into good
space."

"And so the Chief thinks this fellow with the ape and the mouses and the
kangaroo is a criminal and made them criminals?"

Roger nodded.

They waited until the staff checked up with Grover all results from the
day's experiments, and departed. Doctor Ryder, assured that his rats
were not a menace, left with the rest.

Then, carrying from the doors, windows, coal-chute, skylight and all
other available openings, wires from microphones set there, Roger and
Potts led them all to a three-stage amplifier, having a delicately
diaphragmed headset in circuit.

With that headset on, if a heart beat within a foot of any mike, a
drum-beat could be heard in the headset.

Light-beams criss-crossed the entrances so that they must be interrupted
by anybody or any thing that came along. Each was in circuit with one
lamp of a number in a shadow-box, and the one that would stop glowing
would show which beam had been broken.

Thus prepared to be warned well in advance of any intrusion, Roger sat
wearing the headset as he monitored the volume controls.

Police hid inside and outside of the laboratory.

The safe, bathed in invisible rays, was provided with a new form of
"capacity" protection so that anybody or anything touching the metal and
standing with feet on the floor, would form a circuit and overload a
sensitive and delicately balanced radio tube, that would operate a
relay, putting into the circuit a criss-crossed series of small
water-hoses, two playing along each side of a square around the safe,
not easily observed when inactive.

And in that water would be an electric current strong enough to paralyze
and chain, without permanently harming the invader!

He could not avoid it, because the water must fall and no one, even
aware what would happen, could dodge or avoid the spray and the stream.

The precious, priceless synthetic camphor secret was protected.

As he sat, knowing that in the dark around him were Doctor Ryder, Potts,
and his cousin, Roger felt a little thrill of expectancy and uneasiness.

Had he foreseen the outcome of the ruse, it is a question whether he
would have danced for joy or shuddered in terror.

The trap caught something unexpected.




                               Chapter 5
                    WHAT ELECTRICITY COULD NOT CATCH


To Roger, the presence of Doctor Ryder showed that Grover suspected him.
Of the whole staff only he had been told, included in this vigil.

The headset was shifted slightly away from his ears; Roger listened, as
midnight approached, to his cousin's chat with the experimenting medical
man.

"Of course I know that I am under suspicion," Dr. Ryder said. "The
culture was hidden in my section. Other things look bad----"

"Of the whole staff you are the only man I need _not_ suspect," Grover
saw deeper into things than had Roger. "It is an old trick, to turn
suspicion toward an innocent man by 'planting' something."

That, Roger decided, was sounder sense than he had used. He had
forgotten to dig past appearances to the heart of truth!

"What do you expect will happen here?" asked the doctor.

"The miscreant will come, with his menagerie, for the priceless camphor
secret."

"Pretty smart stuff," broke in Potts, "coagulating camphor with
kangaroos."

Coagulating was the wrong word, Roger knew; and the others saw through
the meaning.

"Claws on glass implied something tall enough to reach up that high on
top of the cage," Grover explained. "The 'snake' trail and an animal
with a dragging tail 'coagulated.'"

"But why did the man take the white rats?" Potts was beaming, in the
faint glow from the bulbs in the shadow box; tickled that his word had
been so good; not dreaming that Grover was inwardly amused.

"With the same motive that makes a magician do meaningless movements
with his left hand while he really palms cards in his other hand," Dr.
Ryder explained, "to make you look away from the real motive."

"And he brought the kangaroo and the ape to confusicate us," Potts was
being clever, he felt.

"I'd say the ape came so he could be used to climb down a rope, and go
and open the cellar trap that had no beam-alarm," Roger spoke up. "I
looked up notices in the theatre columns and there is an act that has a
boxing kangaroo, and the critic called it 'she.' In the act, she 'brings
down the house' when a fire is supposed to trap the trained rats on the
roof of a little house, and 'she' makes everybody laugh by taking the
rats and putting them in the pouch they have to carry their young in."

"Oh, yes, that coagulates," Potts agreed.

Although all the others realized that the word meant to clot or curdle,
and wanted to smile when it was used to mean "connects up," Potts, had
they known it, was precisely correct--for they were to find that many
deductions certainly coagulated, in a broad way of speaking, the real
truth, instead of solving the mystery.

If clotting and curdling means to thicken and make lumpy, then as Potts
said, Roger's explanation did exactly that to their deductive
cleverness.

Roger, as the slow minutes dragged along, picked up with his headset
whispers of the policemen outside a window, exchanging ideas about their
tedious watch; and even the slip and rattle of shifting coal in the
cellar bin.

No invading menagerie, though, brought news to his intent ears.

A tiny, but sharp click broke a long silence. The oil-burner relays of
heating plants in adjoining buildings made such "static" on his home
radio, he knew, but the heat would not be used in the hour after
midnight.

None of the apparatus or light was on the laboratory.

The interpretation Roger gave was that in moving he had jarred some poor
connection that made loose contact in his circuits; and he began testing
his wires at soldered points, seating tubes, and shaking headset binding
posts.

He did not succeed in locating the source of the single sound, because
things began to happen.

From the darkness, and apparently from the upper floor, in a hollow,
grave-yard sort of tone, an unexpected voice spoke.

Roger, with power full-on, got a roar, and dashed aside the set to save
his ear-drums, for a microphone had caught and had brought him what the
others heard naturally.

The voice spoke in English, low, deep, mournful and yet, somehow,
menacing, as it said:

"_Hear me. I am the Voice of Doom!_"

Roger felt his blood "coagulate" in very truth. Grover, never more calm,
although the unforeseen and uncanny call galvanized and terrified Potts
and made the Doctor's face look absolutely horrified, leaped up, and
vanished out of the small pool of dull light from the shadow-boxed
panel. With the ease of familiarity, he got past their great
transformers, and the storage batteries from which direct current was
drawn for certain types of experimentation. He avoided, in the gloom,
the new high-intensity-spark mechanism, and took the stairs two at a
bound.

Roger, impulsively starting to follow, remembered his duty, and in spite
of his shuddering nerves and the cold fear always coming from any
uncanny and unexplained happening, he stuck to his post.

Doctor Ryder, attempting to follow, ran into the recording equipment and
stopped, hesitating, as Grover, from above, threw on the lights. Roger
got the switch-snap, but it differed from his other "click."

"Nothing here," Grover called down. "Strange!"

"Potts," Doctor Ryder turned his head, half accusingly, "are you a
ventriloquist?"

"A----"

"Ventriloquist! Able to throw your voice so that it sounds as if it came
from somewhere else than where you are."

"Are you?" asked Roger suddenly.

The other laughed.

Grover, leaving the lights going, came down, switching on illumination
all over the building; while several policemen came from concealment,
blinking and staring around uncertainly, the experimenter in the bright
light walked over and sat beside Roger.

"Watch me closely," he half-smiled, but kept his eyes glancing around
half fearfully. "I did not dream--it would happen--again--and here!"

He spoke as if to himself.

"No, that is not ventriloquism," he muttered. "It is some art of the Far
East, known to the Lamas of Tibet----"

Again, and in the same hoarse, menacing, hollow way, the sound was
repeated:

"Hear me! I am the Voice of Doom."

Potts was shaking with fright. Uncanny and weird, the sound woke in the
rather poorly educated man all the primitive fears and superstitions of
his ancestors.

Grover, listening with his head on one side, his eyes on the Doctor,
spoke:

"He isn't a ventriloquist, Roger. The changes in muscular and other
throat parts developed by constant ventriloquial practice, do not show.
We took a film, remember, of just such throat development in connection
with our research for the clue to our case when the deaf man 'heard
things.'"

Roger, recalling that in that case a tiny click had also come, when he
had listened on a headset, jumped to the conclusion that he had before
found correct.

"Somebody is using Mr. Ellison's little radio test-sender," he declared,
confidently.

Grover nodded. "Possibly. Go and see."

"His private locker needs a key that is in the safe."

"Never mind, then. I think you have the explanation, Roger."

Grover sat down again, relieved, as was Potts.

Dr. Ryder, though, seemed unconvinced.

"Sorry, but I must dispute your deduction," he asserted. "I have heard
that voice before, and it is sent by some Asiatic, wise in use of the
hidden forces of Nature. It is a manifestation that is directly intended
for me."

Roger stared at him.

"'Manifestation'? You mean--like thought transference or the 'ghosts'
that spirit-mediums pretend to call on?"

"Only this is more sinister and terrible, because it is the way that the
Far East makes known to some intended victim the fact that he is to be
punished."

He rose, and began to pace.

Roger, suddenly intent, caught at a passing "hunch."

"Appearances" could be falsified. It appeared to be fact that something
uncanny was happening. Might it not be the same sort of misleading use
of one hand to distract attention while the other did some trick, as
with the white rats that "appeared" to have been inoculated, were
apparently "stolen" and so on?

Quickly the headset was put on. He cut the output strength to avoid
having his ears blasted if the microphone upstairs picked up that
booming, hollow voice again.

Grover, intently considering the Doctor's last words, spoke:

"What do you mean by saying that you are being warned by some occult
means that you are marked to be a victim?"

The man addressed held up a hand.

"It will tell you!" His face was set; he was listening.

Again Roger heard the inexplicable sound.

This time, no voice! Beginning in a low moan, faint and very much like
the whine of a puppy that is hungry, it grew in volume, and its tone
changed from a high falsetto, running down the scale and then up again,
in cycles, constantly growing louder, while Grover, again rushing to the
upper floor, stood looking around as, with a great grinding and rumble,
following the last piercing roar of the sound, there fell silence.

Doctor Ryder, rising, walked around the recording machinery and Mr.
Ellison's newest camera, that worked with a stroboscopic lamp and ran
its film so fast that no shutter was needed, as daylight did not act on
it long enough in any spot to fog it.

"That," he called upward, "was the real Voice of Doom."

Grover, bidding Roger turn over the monitoring work to Potts, summoned
his younger cousin.

"Roger," as the hurrying figure came into the room with the vacant glass
experiment-cage, "are you afraid to stay up here?"

"Not much--but if I am, I will stay, just the same."

"Then set up that sound camera, with film, so you can take in every foot
of this partitioned room. Be ready, and if the voice comes again, switch
on, for continuous takes."

"You think--anybody is hiding?"

"No. But a voice means something vibrating. I could not locate anything.
The camera might do so."

He went down, to give Potts some instructions and took over the
monitor's post while the handy man executed his order, which was to mix
fresh developers and fixing baths, and to be ready for whatever Roger
caught.

Doctor Ryder, helpful and desiring, as he made plain, to take away
Roger's sense of fear by explaining how the Far East made so uncanny a
manifestation by mental powers, handed him the can of non-flam negative
so that Roger lost no time in "threading up" and getting all ready for
his duty.

Alert and steady, in spite of his chill of nervous uncertainty as to
what might come next, Roger heard, seemingly from a corner of the small
room, a thump.

"Start it!" gasped the man beside him.

But when two minutes of time had run out the film in his magazine and
nothing more had come, Roger disappointedly took the film into the dark
room and changed the magazines, hurrying back.

Half an hour later, with nothing to break the tedium, the next amazing
development came. Potts, in the dark-room, shouted, and tore out into
the light, waving a damp strip of film. He had developed the film on the
chance that the thump had caused some change.

Instead, developing that film, he had brought, to wave before Roger's
startled eyes, an impossible thing.

On that film, in a different position on each Frame, or individual
picture, a spectral monkey and an equally indistinct kangaroo hopped,
bounced, and skipped, finally vanishing into thin air!




                               Chapter 6
                             A WEIRD STORY


When that uncanny film was projected before him Grover seemed unwilling
to believe the testimony of his eyes.

"It simply could not be," he declared. "That film was taken from a brand
new shipment, wasn't it?"

"Yes," Roger asserted.

"And there were no animals in the laboratory."

"Not animals we could see," said Doctor Ryder meaningly.

Grover, rather sharply, demanded his exact reason for saying that.

"I have heard the voices that seem to come out of nowhere," the
experimenter explained. "I have traveled in the Oriental countries. I
have heard strange things; and I have _seen_ things even more odd. In
India, in China, and all the more in Tibet, there is what they call the
sect of the Bon--Black Magicians."

"Nonsense!" exclaimed Grover.

"To a scientific mind--yes. To an ignorant native of a country without
educational facilities or communication such as our radio, telephone and
so on--not so nonsensical. Besides, I have heard and I have seen curious
things."

"Like what?" Tip demanded.

"In India, a seed planted and an orange bush growing before my eyes. Or
a rope flung into the air, staying aloft as if hooked to some invisible
support, while a boy clambers up and seems to vanish.

"In Tibet, as well as in India, men who can apparently walk on water. Of
course, our science explains it as hypnotism--the man who performs the
feats is able to secure control over some part of the onlooker's mind,
impress _his_ thoughts on the other mind, and make one believe the trick
is a real occurrence."

"I have read about men who can walk on pits of live coals," Roger added.

"Those tricks or those marvels do not explain this film," Grover was not
satisfied, Roger knew by his tone.

"How about telepathy? Thought transference?"

"I believe," Grover answered, "there is some ground for accepting that
as possible. It might be reasonable to admit that if a man, by years of
practice, can train himself and also treat his feet so that he can walk
on fiery coals, a man might become able to impress a powerful idea on
another without words. But--on a film!"

"In the sect of the Bon, or manipulators of the darker forces of Nature
and of man's superstition which is half of black magic," the
experimenter declared, "strange powers exist. I have read of a French
scientist who has succeeded in developing a film so sensitive that a
powerful thought, held by his trained mind, seemed to cause some changes
in the film. This is a similar situation produced by some Oriental
master mind, probably."

"Or it could be that things like ghosts are true," Potts volunteered.
"What do we know about the unseen things? Even science is finding things
like bacterions----"

"Bacteria," Grover corrected, smiling.

"--In the air and water and blood. Well--I went to a spirit-meeting
once. The woman threw a fit and talked awful funny about my 'deceased
aunt on the other side' and told me things--now, if we brought in one of
them there test mediators----"

"Test mediums," Roger knew the right word. "They pretend to be able to
communicate with spirits of people, but has it been verified?"

Potts was too eager to argue that. He stuck to his suggestion:

"All right. If we call in a trance medium, she'd tell us them spooks is
around us, right now."

"Just because the appearance seems to be that," Grover stated, "is no
basis for accepting the explanation of telepathy. In that case, Doctor,
_we_ would have seen the objects, the animals. We did not. You and Roger
are sure you saw nothing. There are only two possible ways the
phenomenon could happen."

"How?" Potts was anxious, eager.

"First: the film had been exposed, previously. Second: some one hiding
in the dark-room, while Potiphar was not closely observing the
developing tank, changed for the original film in its rubber wrapping,
this one."

"I used a deep tray, full of pyro," Potts stated, "wound the negative
around in the rubber, but didn't use a tank, on account of them bein'
stained, and you was so positive about fresh stuff, I got a deep tray,
never used before, and watched every step of developin'. The second way
of it happening is 'out.'"

"Then we will test the possibility of the first," Grover beckoned to
Roger.

"Telephone downstairs for a taxi, and meanwhile, plug in the telephone
in the screening room for me."

When Roger had summoned a night-hawk car, his cousin reported his own
activity.

"I got the night-watchman at the Bizarre Theatre, where the animal act
finishes its engagement tonight," he said. "The white rats and dogs, and
several monkeys are quartered at a pet shop near the theatre. There is a
kangaroo, and it stays in a stable. Here is the address, Roger. I want
you to talk to the keeper, or some stable attendant who can say when the
animal was taken out and when returned."

Roger, when the taxi arrived, sped to his task.

He found a sleepy attendant, surprised at the time, so near dawn, for a
visit from a young fellow who wanted details about the kangaroo.

"She ain't been out this night," the youth assured Roger.

"How about last night? Or the night before?"

"Neither time."

"Oh, but she must have been."

"Well, she wasn't."

"Well, then, was the ape?"

"What ape?"

"Doesn't the man who has the trained animals use an ape?"

"Never saw nor heard of no ape."

Roger was puzzled.

"Well--" He recalled a flash of inspiration that had been all his own.
He pulled from his pocket the tiny, compact camera, small
magnesium-flash gun, and tripod folding like a pocket ruler, very
slender, but sturdy when unfurled.

"Can I snap her picture? Our laboratory wants it to study."

"Cost you--how much you want to pay?"

"A quarter."

"Go to it, buddy."

Roger, with the hand of the youth clutching the coin, got a good snap
just as the flash startled and almost stampeded the kangaroo and several
horses and a few mules quartered there.

He returned by taxi as the East streaked rosily to the rising of the
sun.

"There was the kangaroo, but she had not been out--at least, the
attendant vowed she hadn't," he said. "But I've got her picture to
compare with the ghost-one."

"Clever head," commended his older cousin. He went away, pleased, to
develop, print and fix his prize.

While negative and contact print were being fixed and washed, he sat at
the table in the adjoining room where the mysterious voice and roaring
cry had been located, thinking hard.

"I wonder," he mused, "if it _could_ be that the film I used had some
sort of emulsion that would be sensitive to rays we don't see. You can
take a picture through a quartz lens in a room that seems to be pitchy
black. I've done it, with our special equipment. Maybe a film coating
that has some light-sensitive ingredient sensitive to high-frequency
vibrations of light, could catch what we don't see, and--who can dispute
this?--there may be in the air, all around us, forms of things that we
can't see."

Science, he reflected, had managed to develop instruments so delicately
adjusted that they caught earth tremors and recorded them, when the
disturbance might be hundreds, thousands of miles away from the
seismograph.

Their own Mr. Ellison, the cleverest and best informed man in the city,
on electrical matters, was preparing a camera that ran its film at high
speed past an aperture: a light more actinic than sunshine alternately
lit and was out, but so rapidly that its flashes impressed pictures lit
by it on the film, as many as a half million or more a minute, he
believed. The papers had written it up as that many.

And scientific instruments pictured, in graphs, of course, such
invisible things as electrical waves; yes, and radio made audible the
inaudible electrical frequencies sent by an aerial, caught by another,
transformed into sounds by other invisible agencies.

Grover, when appealed to, nodded.

"Anyone who has operated a modern laboratory knows better than to make
fun of any theory," he admitted. "What our Pilgrim ancestors would have
called a witch talking to Satan, we see as an old crone listening to her
radio."

"They had their witches-on-broomsticks," Roger chuckled. "We see
airplanes. That's so."

"It doesn't pay to scoff at your theory. It may be a scientific
possibility to prove it correct, some day. But, just yet, let's not take
it as the only explanation of our ghosts. I realize that the film can
was one of our last shipment, that you had to break the label, proving
it had not been tampered with, apparently. Still, some test made at the
film plant could have been inadvertently packed. We got it."

"My snap of the kangaroo will prove or disprove that." Roger went to get
the force-dried bromide enlargement and the camera film taken in the
haunted room. Comparison showed, apparently, the same animal, in one
case sharply defined, a solid object; and in the other, just a shadowy
specter. They looked to have the same proportions, though.

"My theory is that someone hired the animal trainer to send his rats
here, so they could be removed. He could have read notes of the Doctor's
planned experiment in a science column of the papers."

"Then where did the ape come from? The attendant was sure the act did
not have any ape in it." Roger was still unconvinced.

"That may have been the trainer, an agile man, in a masquerade costume
of Tarzan-type."

"It might."

"I will admit that Doctor Ryder tells a story that makes wilder theories
possible," Grover added. "The policemen are gone, now. He gave me an
outline that made me discard the theory about danger to our camphor
substitute. Suppose you listen with me to the full recital."

The narrative the man spun was amazing.

"Shortly after I left college," Doctor Ryder began, "I became interested
in study of medicinal herbs, because an old Indian in up-state New York,
who had earned a reputation as an occult doctor, had made some
astonishing cures of seemingly incurable cases. A friend and I got into
an argument. I supported the Indian's claims; and my chum argued it was
impossible, that it was pure medication and not at all due to magical
powers as the people claimed.

"I went to the Indian to study," he went on. "He took a liking to me,
and after a long time, teaching me secrets of wayside weeds and the
properties of common plants in medication, he confided that in the Far
East there were schools in which full knowledge of herbal medication
could be learned by those qualified to share the secret--a dangerous
one, because knowledge of it might enable some evil-doer to procure
enough deadly poison among common wayside flowers and herbs to destroy a
city's populace."

Skipping his explanations of how he finally secured the Indian's help in
reaching some one who knew more, and of how he finally found himself an
accepted student journeying toward a Lamasery in far-away Tibet, Roger's
next intense interest came with the declaration:

"I learned something about what Ponce de Leon spent his time seeking,
the secret of eternal youth. I learned much about marvelous properties
of common plants--and then, through a desire to view with my own eyes
the greatly revered Eye of Om--a precious jewel set in the forehead of a
sacred statue of Buddha--I became a hunted man, suspected of a theft I
never dreamed of committing, then. The Eye disappeared. I was suspected.
My perils were many. I finally escaped from the land. But twice, since I
began my private researches, I have been reached by that strange
warning, the Voice of Doom--just as you, who have been my friends, heard
it tonight."

He bent forward in his chair, earnest, eager.

"I know who took the Eye of Om. If only you would help me to restore
it--if only you _could_."




                               Chapter 7
                         SCIENCE TO THE RESCUE


When he heard Doctor Ryder's startling plea, Roger's clear, gray eyes
lighted with a fire of hope and excitement.

To be involved in a mystery in the laboratory was thrilling; but to have
a share in restoring the Eye of Om, evidently a priceless gem, would be
more so.

His quick mind flashed over the fascinating prospect; but with equal
quickness he saw the reason why Grover sat so silent and unimpressed.

A man accused, anxious to return a jewel, would merit help. A man who
knew the real taker of the gem and wanted it restored meant possible
trouble. He might want them to help him get the gem away from its
possessor.

That was not their duty. It was police work.

"Please be more definite," Grover said.

"I don't want you to help me 'steal' the gem from anybody," the medical
experimenter declared. "I need financial help to buy it."

"To buy it," Roger exclaimed. "That would take a lot of money. Would the
people in Tibet pay you?"

"They would pay a handsome profit, Roger. But it would not cost such a
vast sum as you may think. You see, the one who has it is not aware of
its value."

"That is curious," remarked Grover.

"What happened was this: I went to the temple with a native priest to
see the marvel I had heard of. While we were entering, a figure slipped
away out of another door to the sacred crypt. As we approached the great
figure of Buddha, I saw a vacant hole in it and realized that the
priceless jewel was gone. Terrified at the thought of being caught,
suspected or in some way associated with the crime against their holiest
treasure and venerated religious symbol, the priest and I hurried away
just as other temple attendants discovered the situation."

Without being certain, the rest of the gem's history was assumed to be
that the thief, terrified, had thrown away his loot. One of his camp
staff, an ignorant, though strong pack-carrying youth from an American
city, whose way the doctor had paid for his ability to obey orders
without trying to improve on them, had found the gem, in a fissure of
the great mountain pass they traversed in escaping.

He had evidently taken it to be only a beautiful native art object and
had put it in his pack, apparently, without mentioning it, meaning to
bring it back to America to "give to his sweetheart," as the medical
experimenter supposed.

"At any rate," Doctor Ryder summed up, "he is living here in the city,
his sweetheart had forgotten him, he has that treasure, put away, and I
dare not go and talk to him about it. I know he has it because he has
shown it, as a souvenir, to people who have recognized its worth without
knowing just what it is. He would probably sell it for a fairly good
sum, if approached by someone from a museum; but if he was told its
history, and knew its real value, he might sell it to some gem dealer
who would put it beyond my reach in some private collection. And my life
would be forfeit, because I cannot prove, in the circumstances, my
innocence to the Tibetan Dalai Lama and his vindictive, fanatical
subordinates."

Grover, as Roger watched him eagerly, anxiously, considered the
situation thoughtfully.

"I suppose that there are complications," he said, finally. "Some
international jewel thieves must know the affair."

"Exactly." The other man nodded. "That accounts for the entry, here,
night before last. From the use of a kangaroo I would assume that an
Australian is interested----"

"An ape would mean somebody from Africa," Roger argued.

"While the strange projection of the Voice of Doom implies that the
Tibetans are preparing to strike at me," Doctor Ryder added.

Grover sat considering the matter.

"With that all granted," he said, finally, "it is easy to see what
caused the queer ghost-figures in our film. I assume that the purpose of
using the trained boxing kangaroo with a pouch to carry its young, also
trained to 'rescue' from fire, was to furnish a novel way of hiding and
removing the gem which evidently the thieves think, as do the Tibetans,
that you have."

"Certainly. In your safe."

"And whoever came," Roger was able to fill it all in, now, "with the
kangaroo, meant to get into the safe, get the gem, put it in the
animal's pouch, and then, to make it go away safely, he had to turn on
the fire alarm that rang a bell, the way it must ring in the act, for
the kangaroo's signal to rescue the rats. It rescued them, and hopped
away, to its attendant, just the way it would in the theatre."

"And what about the film?" asked Doctor Ryder.

"Some was probably in the 'sound camera' by the cage. Either in trying
to shut it off or in an accidental knock against it by the animal, the
'continuous' lever was thrown. Focused with a diaphragm opening to catch
the white rats' movements under a vivid light, the lens got only an
under-exposure in the light from the ceiling!"

"Logically," Grover finished up for his younger cousin, "the man knew
the camera had been running. He took out that magazine, took the blank
film from the new can to replace it, making as many snaps as had been
made of the rats, jarred the continuous-take lever on by accident,
giving us the clue of claws-on-glass as his animal came to the cage,
with the ringing of the alarm bell."

"Science to the rescue!" Roger exclaimed. "Now we know it must be the
animal trainer who is the key-man. If he did it for his own greed, we
can protect ourselves from him in the future."

"If he was a hired accomplice of others, as I assume to be most likely,"
Grover added, "he can be compelled to tell us the facts."

Declaring that he would interview the man in person, bidding Roger to
add to the few hours of sleep secured before their midnight watch, the
laboratory head, as the staff began to arrive, urged Doctor Ryder to say
little, and to wait until consideration could be given to his plea that
they help him get the Eye of Om.

On the emergency couch, in a small combination of rest-and-first-aid
room, Roger stretched out without feeling the least bit drowsy.

The excitement was still keeping him alert.

"Science to the rescue," he mused. "Modern apparatus is wonderful and
understanding how it works and what can be done with it ought to help
people solve many mysteries. They have developed instruments to measure
nerve responses and other things. There is the lie-detector for one
device to help fight crime.

"And if scientific appliances, and scientific understanding, both can be
coupled with Cousin Grover's axiom about ignoring appearances and
digging to the heart of truth, analyzing down to the basic element of a
complex combination, it will be even better."

He thought back along the course of the many happenings, and of all the
clues that scientific apparatus and wisdom had opened up.

He sat up suddenly.

"Science to the rescue!" he repeated to himself. "We don't need to wait
to see if the animal trainer will tell the truth. We can find out right
away."

In the files he found the enlargements made the day before, from the
"routine" wide-angle and close-up views Potts had taken.

The folder full of pictures, and the rolls of film from the cabinet he
studied carefully.

Roger's study was concentrated on the close-up and magnified detail of
door locks, window catches and all openings.

If any catch had been moved the picture should show to the
screen-observing youth, some abrasion, or some disturbance of rust, or
at least a displacement of the accumulated dust.

Nothing. Nothing in any picture, on any film!

"That tells me that the entry was made through the skylight, as we had
thought," he decided, but added:

"Or--does it tell more?"

An ape, he felt sure, could not have been trained, or have sense, to
swing so as not to touch a magnetized and super-charged metal plate
concealed by being painted the same color as the wooden floor under the
skylight.

A man, dressed as an ape, might. But it seemed like a long way to go
around to get through, when a more simple possibility was open.

Roger assumed that it might be possible that one of the people
interested in securing that priceless treasure which could be supposed
to be in their safe, could work there!

The fact that no pressure from outside had given its clue in the
pictures, showed him that some "insider" might have opened the only
possible place to get the kangaroo in--the coal chute.

His examination, with a high-powered, beam-focusing light and a
magnifying lens, revealed that rust under the bolt had been scraped.

But the pictures had shown no sign of the use of "jimmy" or other
implement for prying back bolts!

An "insider" was responsible for opening that chute trap.

It would be simple to associate kangaroos with Australians, apes with
Africa, possibly India. It would be just as easy to narrow it down to
whether any of the staff connected-in with either place.

A man from Australia would naturally think of a kangaroo and its
peculiar qualities and usefulness for his plan. A man familiar with a
country wherein apes were found might see the usefulness of that animal,
or would resort to a costume for disguise that a man from the coal
counties of Pennsylvania, for instance, would not have thought of.

To the office files Roger hurried. All the data concerning each employe,
such as age, experience and so on, was there.

When he had looked, Roger put away the sheets of data carefully, and
waited eagerly for Grover to return from interviewing the trainer.

Two sheets had told him much. One had given its maker's experience on an
expedition to India for a power-plant construction job. There was India,
ape country. Roger knew that in many sections of India, apes were
sacred.

The other sheet had told him that its maker had worked in Australia
under Government chemists, studying the inroads of a destructive insect.

He had two names to give Grover.

Science, with brains, _had_ come to the rescue.




                               Chapter 8
                         BASKETBALL AND BRAINS


"Admitting your cleverness," Grover, informed by Roger, was more than
surprised, "I still find it hard to accept your deductions."

"I don't deduce anything," Roger argued, "I only got the facts. I think
I would almost as soon suspect you as to suspect Mr. Zendt, or Mr.
Ellison. But----"

"The appearances certainly look bad," Grover agreed.

Zendt, quiet, calm, thorough, had been in Australia, his own record
attested. Mr. Ellison, than whom no one was more clever in electrical
matters, had built power plants for a big utility company, some of his
work having been in Calcutta and Karachi, both Indian cities.

"I will watch them unobtrusively," Grover stated, "while you do an
errand for me."

Roger waited for instructions.

"I went to the address given by Doctor Ryder, just to check up and see
if his fantastic story had any basis of fact," Grover told his cousin.
"Sure enough, there was dull-witted Toby Smith, and when I represented
myself as an attache of a museum--I am, you remember, one of the
sub-committee on Egyptian Embalming research--the young fellow, about
twenty-two, promptly enough produced and let me study the memento of his
adventurous trip into Tibet. He certainly does not realize its value,
and to me, inexperienced as I am, it appears to be a marvel of Nature's
crystallizing stresses, as well as a credit to the Tibetan jeweler's
craftsmanship."

Roger was all ears.

"To him it was a souvenir, with little other value--a bit of art-glass,
he told me he supposed it was.

"I bought it. You are to go and get it."

"Why wouldn't he let you bring it?"

"I thought of the possibility of being watched----"

Oh, boy! was Roger's mental comment.

"I satisfied myself that I had not been; however, I had arranged to have
you take him, in return, a small moving-picture hand-camera that he had
confided to be his heart's desire. In exchange, he will surrender to you
a large envelope which will contain, disguised in heavy
documentary-looking papers, the art-glass." Grover smiled amusedly.

"And if you have any matches or duplicates in your stamp collection, you
might get intimate enough to trade for some of his foreign over-stock of
stamps."

"I'll take a batch of duplicates," agreed Roger.

His taxi, depositing him at the address given by Dr. Ryder, waited.

The Smith chap, he found, was intensely interested in collecting, and
had a fine collection of stamps; in fact, he spent most of his small
earnings as a dishwasher, on philatelic prizes.

He and Roger grew intimate and compared notes, exchanged stamps, and
chatted about the Tibetan expedition Smith had joined as a young man,
several years ago, he claimed.

He told about a Devil Dance, a religious rite, he had seen, wherein all
the devils and evil spirits were represented by disguised and
horrible-looking men, who chased a wildly terrified human soul, as a boy
represented himself to be in the pantomimic dance. Exhausted, unable to
escape, at last, he was supposed to be destroyed.

"It is supposed to show how we are chased by temptations and all," Toby
Smith explained; and he told of the Tibetan huts and other nomadic
possessions of the ever-moving grazers, and other interesting sights.
Then he gave Roger the heavy, sealed packet--Roger felt the lump
supposed to be the gem. Putting it in his coat with his stamp envelope,
Roger took his leave a little regretfully. Smith had been an interesting
person to talk with.

However, he concluded, he would, as he had promised, help with the new
and mystifying hobby of taking "movies."

The taxi--he had forgotten about it--was gone.

That did not much surprise Roger. The man had no doubt gone back to the
laboratory or had gone on elsewhere. In the first case they would have
told him they had a charge account with his company; in the other,
knowing it, he would have picked up other fares and forgotten the young
man he had brought there.

Roger, rather closely confined indoors by his laboratory work of giving
out hypo, sodium bisulphite, or, perhaps, electrical requisites, decided
that the air would be beneficial. He walked.

It came to him after a few squares that Cousin Grover had thought of
being watched. Roger glanced around hastily.

He wondered if that slouching fellow with the low-brimmed hat, could be
following him. He whirled in his tracks, to retrace his way past the
other, but the youth turned in at a cigar store, and Roger, with
reassurance making him whistle gaily, walked on.

Almost at the laboratory street he looked back again--and was puzzled.

The youth was on the trail, possibly, once more. But he had not kept
close; instead he was leaning against another smoking goods shop
window-frame. Roger, thinking to himself that such espionage could do no
harm, changed his course, and instead of going directly down to the
laboratory street, he turned into the one behind the laboratory, so that
if the youth had gone into the store to telephone his progress, he would
prevent being met by anyone at the logical corner he had been heading
for. He would approach from the far end of the block.

To his dismay, this seemed to have been anticipated. There were about a
dozen boisterous, rowdyish young men and boys racing to and fro in a
rough, noisy game of tag. They might be innocent of any interest in him
and his tight-buttoned coat; but he was taking no chances. He turned,
retracing his way. To his dismay, one, being chased by the pack, came
with long legs down the street. Roger stopped at a drug store intending
to go in and telephone for Tip; but a woman with a baby carriage
obstructed the entranceway.

He changed his plan quickly. Dodging around her, he walked rapidly
toward the candy factory adjoining the laboratory. The roughs were
passing him. Suddenly they were all thronging around, pushing, not
caring whether he got into the mixup of thrusting, hoarse-yelling
gamesters or not. Roger felt a little bit dismayed.

One of the tougher and taller youths caught hold of his tightly buttoned
coat.

"What you buttin' in our game fer, huh?"

Roger spoke quietly.

"I wasn't."

The hold on his coat was too tight to break; they were behind him as
well, and escape was impossible.

"What you got in your coat--candy?"

"Nothing much but a packet of lyddite--the explosive. Be careful!"

His ruse was not successful. One caught his shoulder.

"What's that, now lyddite?"

The grip of the other held, and Roger felt the buttons rip out.

As quick as a flash he had his hands on the packets: feeling told him
which was which. He snatched one out, and with his eyes fixed over the
heads of those he faced, he shouted:

"Catch it, Tip. Here she comes!" and he made a move to back out when
they would turn to see who he spoke to. But that ruse also failed and in
sudden desperation Roger realized that he must keep them from noticing
that his coat pocket still held something.

His basket-ball skill, that had enabled him to make goals by the tosses
that seemed impossible with antagonists all around him, he summoned to
help in his crisis.

He had noticed in the second floor office window, the work basket some
woman had put aside, full of samples she had brought in from the
wrapping machines.

With a deft flexing of muscles and a quick eye-glance to make sure of
distance, wind and other factors, as hands stretched to snatch his
packet, Roger gave it the well-rehearsed basket-ward toss. He saw it, as
baffled, disconcerted youths looked up, fly in a clean trajectory to
lose momentum just above the basket. It seemed to hover in the air. It
dropped into the basket. It stayed therein.

As if trying to recover a loss caused by such quick thinking, the
ringleader wheeled and raced into the building, evidently to ask for the
envelope thrown up by a boy at play.

Roger, as the rest hesitated, pushed through, and hurried for the lab.
The others broke and fled.

"Tip," Roger greeted the handy man as he entered, "I'm going to phone
the people next door to hold an envelope full of stamps I threw into one
of their baskets to save it from a gang of rowdies. Will you go and
recover it, please? I have to deliver a more precious pack to my
cousin."

Tip brought back the stamps, quite safe.

And, also quite safe, their strong-box held a scintillating, vivid,
thousand-faceted emerald, flashing its sun-fires of refracted light; as
it had done when in the forehead of the Buddha it had symbolized, the
all-seeing, all-ways-looking Eye of Om!




                               Chapter 9
                        THE VOICE IN THE SILENCE


"Had your sleep out?" Grover shook his cousin. "It's almost eight and
Aunt Ella has the bacon on."

Roger rubbed his eyes, snapped awake.

"Is it all right at the lab.?"

"I knew it would be. We left Tip to take turns watching with the men
from the Falcon Patrol Agency. Two at a time, one on each floor. But I
never count on human watchmen alone. They can be careless," Grover
talked as Roger dressed.

"I know. Capacity-overloading plates all around, so that anybody or
anything that got near any apparatus would overload an aerial field and
upset a delicate tube and open a relay, stamping the time, and starting
cameras with sound-films in them."

"Exactly. Just talked to Potts. Nothing at all happened."

Arriving at the laboratory, earlier than the staff, Roger and the Chief
verified the static condition.

"What do you think of this?" Grover took his cousin to the
sound-recording mechanism, the type that uses a large phonograph record
for the sound that synchronizes with a film in certain motion picture
studios.

He explained that as a double-check on any possible development, he had
hooked up the recorder to a separate microphone system, all concealed
flat-disk, super-sensitive diaphragm models, that were set in operation
by any interruption of infra-red beams.

"That's something!" commended Roger, examining the arrangements, "of
course, with the reports in, I may as well put away the record to keep
dust off it during the day."

Grover agreed.

Roger moved aside the recorder which had rested on the outer edge of the
disk, just past the polished edge of the wax.

"Here!" he cried out in surprise, "this isn't right. There is a
sound-track cut!"

"There can't be!"

"Well, look, Grover."

The older cousin stared at the abraded surface, the cuts in the surface
of the composition.

"But that is impossible," he stared, unbelievingly.

"Let's give it a playback," urged Roger. He hurried to give the surface
a good brushing with a soft brush, exchanged the diamond-pointed
recorder for the type that hooked up with the electrical amplifiers and
speaker in the screening room.

He adjusted the mechanism to run a minute before lowering the pickup
onto the disk, to give him and his cousin and Tip time to get into their
tiny theatre.

The low rasp of the needle as it ran over ungrooved parts was all they
heard, for several breaths.

Then:

Out of the speakers, amazing, booming like the hollow groans that had
followed the voices--as they now did!--came the ghostly salutation and
warning:

"Hear me! I am the Voice of Doom."

Again, while they stared at each other with dilated eyes, the needle ran
with no pickup. Then, again:

"Hear me! I am the Voice of Doom."

There rose that whining, shrieking moan of the demented and tortured
puppy, lowering in pitch until it became a hoarse and strident howl,
slowly falling away in volume but dropping in pitch until it sounded
like the moan of wind through stretched silk, ending, as had ended the
original, spooky manifestation upstairs, in a grinding, abrupt rumble
and silence.

Before the staff got there Roger had developed the sound-films of all
the small cameras, but not one had been impressed with picture or
audible sound record.

It was uncanny and inexplicable.

The Falcon men and Potts declared solemnly, and with sincerity, that
they had seen nothing, had heard nothing.

This supernatural appearance startled even Grover. Though he did not
depart from his usual calm or drop his cold poise, he looked more than
ever solemn, and even mistrusted human watchers and his
electricity-and-water protective device so far as to search the safe.

The jewel, as well as the camphor data and other precious things, to
his, and Roger's, relief, were intact.

Doctor Ryder, who was given a demonstration of the spectral recording,
looked dismayed.

"If I do not return that stone," he gasped, "my life is not worth
insuring. This is the third warning, and conveyed in a way that makes me
very certain that we are dealing with a sinister and very occult body of
priests."

"How do you propose to return the jewel?" Grover was practical.

"I dare not let it be known that I have it," the medical experimenter
declared. "I have thought of going to Tibet--but how shall I get into
that temple, and how give back the gem? White people will be all the
more forbidden access to the place; and I am already suspected of having
taken the Eye."

Grover considered it seriously.

Roger, too, gave his best thought to the puzzling complications.

"I don't suppose they'd have radios in temples in Tibet," Roger said,
half-hopefully.

"In the Dalai Lama's palace there is a radio, yes."

"Short-wave?"

"Probably of the best. We cannot resort to broadcasting, Roger," his
cousin objected, "the international gem thieves might pick it up."

"That's so----"

"Besides, to ask them to come and take it, as I suppose you had in mind,
would bring every gem hunter, in disguise or otherwise. And it might
lead to worse consequences than theft. They are fairly desperate, cold
blooded people," was the doctor's objection.

Tip, listening, put in a suggestion.

"Let one o' them that's been fetchin' kangaroos and apes take it. _Then_
radio who's in the possessive case. Let _them_ get the Voice of Doom
after them."

Grover smiled, shaking his head.

"Tip and I could take it in an airplane," Roger hinted eagerly.

"There is only one logical course open," Grover gave final decision,
"hold everything static. Make no move. Safeguard Doctor Ryder, with the
same type of protection we have given the safe, in a modified form.
Then, when the promised Doom arrives, its emissaries can be informed
that if they furnish proper credentials they may have their Eye of Om."

Tip looked as disappointed as did Roger.

No Tibet? No adventure? No thrills?

"I suppose," Doctor Ryder shrugged, "it is the sure way, though not too
safe for me, no matter what devices you arrange. If you knew the hidden
forces of Nature that those Lamas can call into play, modern scientific
protection would be as useful as a child's toys to combat unseen dangers
that strike through the air."

"I will pit my laboratory equipment against any force you can tell me
about," Grover spoke confidently.

"Well--as one example--how would you guard against mental suggestions
sent by a powerful will, in my sleep, perhaps causing me to leap out of
a window?"

"I have heard of such powers," Grover admitted. "I have never seen them
verified. However, for any occult science I am sure that we can find a
material device to counteract at least the effect on your safety."

Although Doctor Ryder was skeptical, he shrugged and submitted.

"I will arrange your room so that nothing can get in, you cannot creep,
crawl, run, jump, push or otherwise escape," smiled the scientist. "I
shan't say what will be set up, and then there can not be any way for
you to frustrate my plan to keep you safe."

Potiphar, with Roger, heard some quiet instructions. The sketch and
specifications they got made both of them chuckle.

Any secret schemer, thief, priest of Tibet, or what, must "go some" to
cheat the mass of light-beams, selenium cells, the recording phonograph,
a camera, and electrified door and window seals that as long as current
held them tight, could open only to Grover's own secret key, filed to
touch only certain contacts in a tiny slot on the circuit-cable just
outside the rooms of the doctor.

Tired and full of content after saying good-night to their protege,
Roger saw the switch set "on" and went home with Grover to sleep
soundly. Nothing could enter or leave that sealed place!

And to show the fallibility of human wisdom, Roger waked again in the
hour before dawn to hear Grover answering a wild summons from a Falcon
Patrol Agency guard at the Ryder home.

"Better come," he was telephoning, "I can't rouse him or get him to
answer; and from the observation port I can't even see him in that
room!"




                               Chapter 10
                         A DEFEAT FOR SCIENCE!


Shudders of superstitious fear shook Roger's nerves as he flung on his
clothes.

Rooms that were locked and barred he had read about in detective
stories; they had been entered. A room not only so sealed but, far
better, sealed by locks that not even Potts or Roger could have
unsealed, was as impenetrable as a solid block of metal.

Yet some uncanny, mysterious thing, force or creature had penetrated!

Unless, and he caught at the idea, unless Doctor Ryder had been
worked-up and nervous, and had dreamed some nightmare that had made him
hide.

No matter what had happened, no matter what force had beaten the
scientific measures employed, they would know the facts, because the
registering devices could not have been stopped by the doctor himself,
let alone any outside person or power. While that current flowed in the
circuits, the devices must operate; and even if any wires were cut,
still the automatic mechanical springs would run the recorder and the
camera.

Driving on speeding wheels, Roger and Grover got there in quick time.
The Falcon man rushed up as they leaped out of the car.

"Every fifteen minutes," he reported, "the way you said, I put my copper
key in the slot on the plate over the observation port you had cut in
his room door, so the plate would move aside as long as I needed to look
to see him in bed. Last time he wasn't there. Up to then he'd looked to
be sleeping sound."

They hurried to the room door, on the second floor, down a hall.

Swiftly, while Roger watched, helping as he could, Grover took an
observation, let Roger see the empty bed and vacant room. The next move
was to test, with ammeter and test-circuit, every electrical wire that
had been necessarily exposed outside the room.

Not a circuit was broken. Not a wire had been cut.

"Very strange," even Grover was baffled, "the current is on, full
strength, in each circuit. Try to get in."

Roger, at a signal from the Falcon man, worked on the door locks with
the keys that rightfully opened them; while the man, on a ladder outside
a window, tried to pry open catches or shift the burglar stopper built
into the casing. No success.

"The man may be dying," the Falcon agent grumbled, "and we stay out
here, testing."

Roger, too, wondered at such callous but methodically exact procedure.

Grover, paying no attention to their tell-tale faces, calmly inserted
his key in the secret cable-slot, and cut out the circuits.

At once Roger was able to turn his door key.

They hurried in.

As he looked around, at the crumpled bed sheets, at the hollow on the
pillow, Roger knew that a man had slept there. How had he been spirited
away? The closet was wide open, and although clothing had been flung
down, although bureau and chifforobe drawers had been upset as if in a
search for something, no signs of violence showed.

"Get the record from the phonograph," Grover had made swift inspection,
"and the camera film. They operated, of course. You can see the grooved
track on the record. We cannot waste time looking for clues here. They
will come from our spies, the film and record, at the studio."

Rapidly they assembled the things needed and drove to the lab.

With Tip, ready, eager, and quick to help, Roger got the film into the
tank waiting on their arrival, and set the screening room turntable for
the playback. In no time after their arrival they listened to the
revealing details--and were again baffled.

The record, after running along for a few seconds, suddenly spoke that
weird warning, "The Voice of Doom!"

As before, it was repeated and was followed by the uncanny and shrill
screech that ran down the scale to a groan that died in a sudden sharp
grinding stop.

"Let it run!" begged Roger as Grover was about to stop the motor, "maybe
he gave us a clue after that waked him up."

There was a scraping of the recording needle running without vibration
over the disk for a few seconds, and then they heard, very faintly
recorded:

"_You_--Clark!----"

"Who's Clark, Cousin Gro----"

"Sh-h-h!"

The recording was again audible:

"How did you get in? What do you want?"

A few instants of silence. How could the answer fail to be recorded?
Roger thought swiftly that a whisper should have left a faint report of
its existence.

"It isn't here.... Look, then.... What do _you_ know about any
laboratory?... I don't know the combination to any safe!... Yes, let's
go there. I will be very glad to go with you, Clark! The great Joseph Z.
Clark----"

Only Doctor Ryder's very easily identified voice gave the responses and
although Roger cut in more output power and added a stage of
transformer-coupled audio, the speakers gave no intermediate words.

They were easily guessed at, of course.

Potts, bringing the film, still sopping, groaned.

"Not a thing on it. Wasn't even exposed."

Grover and Roger looked.

When light acts on a silver-bromide emulsion, it develops dark grains of
silver where light has fallen, leaving the shadows unaffected within the
degree that they lack light, thus giving the shadings that become a
picture in the positive print.

All over, and for its whole length, the film that had run fully three
minutes showed as clear of developed silver as if it had not run through
the machine as evidence proved that it had done.

"A card over the lens," Grover grunted. "Of course! This Joseph Z. Clark
is a clever man."

"And so is Doctor Ryder, for he must have guessed that the recording was
going ahead, and he told us all he could."

"Yes, Roger. And they haven't been here yet."

"So they will walk into a trap," finished Tip.

They made hurried preparations, hiding the Falcon guards and finding
concealment for themselves.

Doctor Ryder had said he would "gladly" bring the man. How wise! He
would know that they would get him, there.

They did not have a long vigil.

In the tell-tale shadow-box panel of lights wired for all entrances, the
one to the cellar coal chute died out.

Roger felt his nerves quiver, his muscles grow taut.

All they had to do was to wait.

When the pair got in, came up the stairs, walked over to the safe, the
infra-red beam would break, tripping relays that set off small
water-streams that would go all ways around the safe, charged with a
current that could chain a marauder in his tracks. Doctor Ryder, knowing
about it, would stay out of range, sending his captor, the miscreant
they wanted, to his defeat.

They crouched, Roger behind the recording device, Grover in the office,
Tip near the stairs to the upper floor, the Falcon guards at three
strategic points near ground-floor windows.

There was the silence of a deserted building as they waited.

Minutes passed. The intruding thief was careful, Roger decided.

Still more time passed draggily.

Roger began to grow cramped, and also very uneasy in his mind.

What was going on? Was it so wise to wait? Why not throw on some light.
Better sidle over and ask Grover? No. Better wait.

He strained his ears.

He heard only what seemed to be the drip of a faucet in the chemical
washing-sinks. Tick! Tick-et-y--tick. Silence. Tick! Tic-tic--tick-y. A
wait. Tick-tick.

He tried to focus his hearing on any other possible sound. The drip-drip
effect seemed to cease. He wondered about it, but decided that it had
not been a faucet but had been a few drops of collected water running
down the drain and striking in the trap.

But as he wondered about it, he began to feel that it had been a
metallic sound, not so much a soft drip.

Risking censure, in his growing uneasiness, he leaped to his feet and
threw into circuit his small pocket flash. Its beam stabbed the
darkness, here, there.

He shouted in dismay and horror.

The safe door, caught in a flick of the beam, stood wide open!

Tip threw a wall switch. No light came.

Then, suddenly, the lights leaped on, water flowed from the hose.

Too late!

Science had been cheated of its guarded treasure!




                               Chapter 11
                            A PUZZLING THUMP


While Tip was rushed out to the street, to drive Grover's car to and
fro, and all around, in pursuit of the elusive, uncanny pair--or had the
man left Doctor Ryder elsewhere?--Roger made the routine photographic
study of every place that could give a clue to that almost spectral
arrival, manipulation of a safe, and retreat.

If only, Roger thought, as he made wide-angle and micro-lens exposures,
if only Tip, excited, had not fumbled that switch!

Had he gotten the lights on a few seconds sooner, they might have seen
what was going on, or could have seen the departing figure. If someone
had been set to watch down cellar! If----!

No use bewailing the past. No use wishing the past could be altered.
Doctor Ryder was evidently a prisoner. His gem--the Tibetan jewel, was
gone. The Voice of Doom had spoken, but it had apparently turned out to
be some person known to the doctor, whom he had recognized, and had
identified for them.

Tip came dashing back. The car had been taken. Later a policeman
returned the abandoned vehicle, and Tip had more photographs to make of
its wheel, door-grips, seats, pedals.

Tracks in the soft smeared stuff with which Grover had made such clues
possible, they found in plenty from coal pile upstairs and straight to
the safe, and, less defined, returning cellarward.

Only one set! Great, over-size tracks. Defeat again, as Roger realized.
Someone had worn huge boots! The shoe-size was unguessable from those
elephantine clues.

Gloves, as well as boots, left them no usable evidences.

Roger, turning over to Tip the final stages of his work, went to Grover,
who sat in the screening room, as dawn broke, and brooded. It seemed to
Roger that his clever cousin, so often hoodwinked and made cheap by some
seemingly more astute operator, was discouraged and certainly baffled.

"Don't lose heart," Roger urged, "we'll get everything to come out
right. All you need is one tiny hint of the truth."

"I must have a dozen," groaned his cousin. "What good are they? My wits
seem to be fogged." He looked disheartened. "I can't get my old sense of
proportion. Everything seems crazy and impossible. You can't enter an
electrically sealed room! You can't open a safe protected by water-jets
and high voltage streams. You can't take camera pictures of animals
jumping around where no animals are visible to the eye!"

"_I_ can't," Roger tried to be jolly and pretend to make a joke. "But
_you_ will see how somebody else did. When we had that mystery about the
revengeful man who nearly sent a chemist crazy, all you needed was one
hint. I happened to be lucky enough----"

"Smart enough!"

"Well--I caught the sound that got me named the Ear Detective. I'm going
to live up to my reputation."

He crossed and stood in front of the downcast cousin.

"_You_ solved the puzzle. You were called, in magazine articles in
true-mystery write-ups--and by the newspaper men--the Mystery Wizard,
who solved scientifically from one tiny sound-clue that
haunted-laboratory thing. You'll do the same with this."

Grover failed to snap out of his dejection.

"You run up and get out your requisitions for needed supplies," Grover
suggested. "I will check up that Clark man, and try to work out a course
of action."

Roger obeyed.

His work was light, and after laying out dark-room supplies, a set of
new distributor points and a replacement insulator on their high-voltage
transformer line, and a few other needs, he sat down to try to think out
some way to help Grover.

With pencil and paper he carried out a decision made during their chat.

In a list, on the order they had come, he put down the sounds he thought
might be important, and even those that did not seem to have any bearing
on the mystery. Opposite them, he set down as many interpretations as he
could figure out.

His list, finished, he scanned thoughtfully. It ran:

         _Sound_                             _Meanings_

 Clicks and hisses on      Claws on glass cage. Rats clawing at the
   film.                     glass inside to get out. Might be a clue to
                             something.
 A faint click in          A distant relay switching in on a heating
   headset.                  oil-burner. Some electrical device
                             somewhere. Does not seem much because it
                             didn't have any effects after it.
 A thump in the corner     Some trash in the corner shifted. A film in
   of the upstairs room      its can shifted. The wall contracting.
   before I started the      Plaster fell. It started me taking pictures
   camera.                   that turned out to have animals, when none
                             were there, but I do not see any bearing on
                             our case.
 The Voice of Doom.        A hoarse voice coming from a room with nobody
                             there. Ventriloquism. Important, but how?
 The Voice of Doom's cry.  Either somebody screaming and being tortured,
                             or somebody pretending it. Or some natural
                             sound like a fog-siren. Must be important.
                             Might be a clue to some place or person.
 The last two on a         Both sounds just like before and clear. Same
   record.                   meanings I think. Must be clues. But how?
 The record of same in     Like the others, only rougher as if it had
   Dr. Ryder's room.         been made with the needle out of exact
                             adjustment, but strong sounds.
 The Doctor's voice        Had waits between sentences. Was his voice,
   after the Voice of        though. Other one answering not audible
   Doom.                     with 3 stages audio.
 Ticks or drip-drip.       Must have been safe combination being
                             operated. How would it be known? Not to a
                             stranger. Doctor Ryder couldn't get it.
                             Grover leaves no memoranda on it.
 Both alarms at home at    Can't mean anything, know what it was, but it
   start.                    was a sound-clue in a way. No fire. Why did
                             fire alarm go off? How start? Monkey?
                             Kangaroo hitting it with paw?

He seemed not to remember any more. He studied his list, trying to find
others to add, new interpretations; but to no avail.

He thought that if he tried increasing and adding radio-frequency tuning
and amplification to his speaker-circuit--make it a regular radio, in
fact, he might get any possible radio sending if that could account for
the silent spaces on the last record.

He made his circuits up, set the electric pick-up over the start of the
record; but with the new hookup he got no new slant.

Only one small addition to his list of sounds, bringing his total up to
eleven sound-clues--possibly--was the little thump, or thud that the
needle transmitted before starting in on the voice with no speaker
answering in its silent waits. Roger could get no further.

He took his series of eleven sounds, including the alarm bell and the
thump that could have been a tiny flaw of the record just on the sound
track, and went to Grover.

"Here are the sounds," he declared. "Maybe one will clear up all your
tangles."

At least, studying the list, Grover was more alert, less depressed,
Roger saw with relief.

He examined the last-made record for the fault that made the odd jarring
of its recording. No flaw showed, even under magnification.

"It's actually part of the record," he got Grover to add to his list of
notes; and then he said to his cousin, "it may mean that the locks went
off, somehow, just there."

"But it doesn't record the re-locking, so that doesn't fit."

"If only we could see any cause for that thumping sound," Roger
reflected out loud. "We might have one more real clue."

If only he had been able to decode the key hidden there!




                               Chapter 12
                            DETECTIVE ROGER


After further consideration of the sound clues, and discussion of the
uncanny appearance of animals on a film, and other points, and without
seeing any light, Grover rose.

"The staff will be arriving any time, now," said he. "Let's look up that
fellow, Joseph Z. Clark, because I want you to do a little
Sherlock-Hawkshaw work if we locate his address."

They took first the telephone book. He was listed, and his address was
in a section of the suburbs given over to large private estates. His
business also was listed. He was a jeweler, and the reason he could own
an estate was shown by his business address in fashionable Fifth Avenue.

"A man would seem to be a suspicious character loitering around a
private estate," Grover looked up, "but a boy----"

"I could wear my old sweater and cap, and ride my bicycle, and it would
be natural for me to rest anywhere along the road, or even go anywhere
to ask my way." Roger caught the spirit of the idea.

"I merely want you to 'look over the land,' and see how things look,"
Grover insisted. "Then after the staff goes, come back and report. That
gives you time for rest between riding out and back."

"After the staff goes--Do you still think?----"

"I have to think everything and nothing until I get a lead."

Roger took his time riding the dozen miles to the easily located point
of espionage. To get there by mid-morning was best.

The estate itself, walled in with ivy-covered stone, quite an extensive
acreage, he reached as the sun approached the zenith.

Near what seemed to be a servants' gateway he sat down by his reclining
bicycle.

From the grass beside the gateway he could see, along the driveway, the
beautifully rolled tennis court, the sweep of lovely lawn, from the main
gateway, winding up to a grand, white mansion, people moving about on
wide verandas or swimming in a distant pool.

"Pretty swell," Roger told himself musingly. "Not the sort of a place to
look for kidnapers or jewel thieves. Unless--as Grover is always so fond
of saying: 'I dig past appearances that can be falsified, to the heart
of truth that can't be changed.'"

He turned it over in his mind. Of course, it would not be past reason
that a prosperous man, with a millionaire's residence, might smuggle
gems, even make a man his prisoner to secure a gem with the world-wide
reputation Doctor Ryder had ascribed to the Eye of Om.

Om--Roger had looked it up--was the reverent name by which the Tibetans
referred to the All Highest, to Our Eternal Father.

It was sometimes spelled A-u-m, also, he had found out.

From his view of the rich, scintillating gem, the unbelievably many,
tiny, flat, facet surfaces, turned in every direction, well symbolised
the name, the Eye of Aum or Om, the All-seeing Gaze of the Supreme God.

Well, for that jewel, what would not some characters do?

He wondered, gazing idly, behind which window Doctor Ryder might be a
prisoner; and he thought how he might discover it.

If the man could look out, he thought, Doctor Ryder might give him some
signal.

He stood up, pretending to stretch, facing the house. He got up on the
wall, and knew that he was noticed, for a footman moved out toward him.
He jumped down, watching the upper windows.

No response. No signal. If only he could be seen from all four sides of
the house, he reflected, it might be different!

"Private property, son," said the footman, arriving at the gate.

Some remembrance of detectives who had "taken the bull by the horns" and
had "bluffed" people into telling the truth, who had tricked suspected
people into revealing things they tried to hide, made Roger act without
fully canvassing what the possible outcome might be.

"Private, yes," he said, grinning mysteriously, "but you'd better ask
Doctor Ryder whether I'd be called a trespasser or not."

His bold stroke brought him a revealing response.

"Huh? Doctor Ryder? Do you know him?"

"I know him," Roger said loftily, "better than he knows the Eye of Om."

"The what of who?"

"Oh, of course--I ought not to have mentioned----" Roger pretended to be
disconcerted, "I--uh--well, never mind."

"How comes it you're out here? Why'n't you ride right on in if you want
the Doctor?"

"I just stopped to rest."

If Roger's words were carelessly intoned, his heart was doing
speed-pulsations. Doctor Ryder was there!

"Well, all right. They didn't know who you were, climbing on our wall."
(_Our_ wall--Roger hid a grin.)

"Guess I'll walk up. Want to bring my machine?"

Might as well enjoy some of the luxury of having servants to wait on
him, Roger chuckled merrily to himself.

"Certainly, sir. You will find Doctor Ryder with Mister Clark, over
beyond the pool, at the first tee of the golf links. Or, would you
rather be announced?"

"'Station O.B.Y's,'" Roger pretended to be a radio announcer, playing on
the phrase, "Oh, be wise," as he shook his head.

"No, thank you. I'll go see the doctor without being heralded."

He walked ahead of the servant, across the lawn.

Before he had passed the girls with gay frocks, joking with their
escorts, and the quartet of laughing, splashing swimmers, he saw the man
he had supposed to be a prisoner.

Doctor Ryder, his bald head and plump frame easily discernible, was
certainly as free as the tall, sallow, thin-cheeked, hatless man in
white flannels who was swinging a golf club over a ball.

"Why--Roger!" The doctor, turning, recognized him as he approached,
"How'd you locate me so soon?"

Roger, coming up, on guard, hiding his surprise at the unexpected
freedom of the man, took on a careless air of wisdom.

"Science!"

"Oh, you laboratory people!" Doctor Ryder smiled. "So my voice _did_
make a record." He turned to the other man, "I told you that
disconnecting the selenium cell wire wouldn't stop the sound from
getting onto the film, any more than you could stop the motor, even if
you did keep it from taking your picture by holding the card by a rubber
band snapped over the lens barrel."

The other man laughed.

"They may have your voice, and welcome," he chuckled, giving the rather
flabbergasted young detective a cheerful grin of welcome, "but they
didn't get my picture, and they won't have my voice, because--well,
young man, how do you imagine I beat that?"

"Wrote your answers," said Roger after an instant of thought.

The man nodded.

"I told you he was clever--who wouldn't be under the Mystery Wizard, as
his older relative is sometimes referred to." Doctor Ryder slapped
Roger's left shoulder.

Roger, cautious, eyes alert, saw no signs of duplicity.

The situation puzzled him.

After all of the mysterious, baffling, weird and unexplained
circumstances, after the strain and excitement, here was the victim of
capture and jewel robbery, about to play golf, laughing, free.

Were "appearances" cheating his common sense? He decided to pretend to
accept conditions, but he watched alertly for clues.

"But I expect you are surprised to see this situation," the man who
owned these acres of wealth declared.

Roger could not dissemble well enough.

"No fair keeping him in the dark," Doctor Ryder prompted. "I was going
to telephone, but we had some details to work out over a few holes of
Scotch Croquet," he laughed at his own allusion to golf. "So you
sleuthed me anyhow. Well, let's put our cards on the table."

"All right," Mr. Clark--the footman's identification--said.

"I was getting the Voice of Doom manifestation again when--how, only he
can reveal--this old traveling chum, who has gone further in making
money than I have in curing spinal disease," Doctor Ryder was speaking,
"stalked into my room."

"Well, I knew you were in danger," the other remarked. "So I just went
in through a cellar window and up the stairs, and just as the Tibetans
were getting the hang of the slotted cable trick to shut off the current
so they could walk in, I knocked down the ring-leader."

Could that have been the thump on the record, Roger asked himself.

"They had a copperized gadget, and so I chased the other two, and used
the gadget, walked in, and brought my old chum out here."

"You might have saved us a lot of worry," Roger spoke abruptly. "We
thought all sorts of terrible things about you, doctor."

"But I said, at the end of the record, that we would go to the safe, and
if all was well there we would come here and communicate."

"The record ran out before it was spoken," said Roger, and he added:

"Well--did you find the jewel safe?"

"Just as Clark drove us up near the laboratory," Doctor Ryder informed
him, "we saw the Tibetans emerge. How they had worked it is beyond me.
But we let them start in a car, trailed it, and when they got out we
jumped them, and after a tussle, sure enough!--they had this, so we took
charge."

There, in his palm, lay the great, flashing emerald!

"Matter of fact," Clark spoke up, "as long as your laboratory Chief
won't help my friend to restore this to Tibet and escape all the
danger--and worse--that those Tibetans can stage, I am going to finance
his trip back to Tibet, and may even go along."

"All right," said Roger, swinging on the soft turf, "I'd better tell
Grover to stop worrying himself about your protection and all."

"You can call from the house--a servant will show you where," the estate
owner suggested, and Roger saw no trickery or exchange of glances to
tell him anything was deceptive in their manner. "While you are telling
him, if you like the idea, you might ask if he can give a good young
radio operator a leave-of-absence to go along. We have had a Roger, the
Ear Detective, so far. We'd be willing to pay expenses and salary to a
Roger, the Scientist, on our trip to restore a priceless religious
symbol."

Roger's jaw dropped, sagging with his astonishment.

"Straight goods," added Doctor Ryder. "The Tibetan priests are bugs
about scientific cleverness. You'd be a help."

"Name your own salary, too," added Mr. Clark.

Roger may have set his feet on greensward; but to him it was as if he
walked on clouds.

But he did not ask Grover over the telephone.

_He_ was not so sure about that frank offer.




                               Chapter 13
                            SCIENTIST ROGER


Brought back to the laboratory in Mr. Clark's car, with one of the
servants delegated to drive the estate carry-all in with his bicycle,
Roger got a new surprise.

Mr. Clark greeted their bio-chemist and their electrical specialist,
respectively Mr. Zendt and Mr. Ellison, as long-missed brothers.

"We attended the same technical college," he told Grover.

"And did we have experiences in India?" chuckled Ellison.

To himself Roger thought that here was some likely link with the
kangaroo and, perhaps, with the ape of the first startling night's
alarm.

He kept his thoughts behind his lips.

"But why must you restore the Eye, at so much risk?" Grover, put in
possession of facts already known to Roger, asked, "Turn it over to
those mysterious Tibetans who open safes and enter sealed rooms."

"That's the rub," Clark declared. "Are they genuine priests? Or
thieves?"

"The Voice of Doom is a genuine manifestation, apparently," Doctor Ryder
added, "at least, in the mountain temple, I heard something similar to
the screaming doom. In some way they produce that noise, on a much
greater scale of volume. It is said to be the Voice of Doom, and is
supposed to come through the lips of their image of Buddha, as an omen,
only when a criminal is being judged by the image, which is to say by
the temple priests--or before some calamity such as an earthquake or
famine year."

"But maybe these fellows are using that, and pretending to be priests
from the Forbidden Land, to scare us into giving up the gem," Mr. Clark
argued.

Real priests, bent on revenge, he insisted, struck first, spoke
afterward, if at all. Or, these might be of some other sect or lamasery,
as they called their mountain retreats.

"I can see that," Ellison agreed.

"It is not from them so much comes the danger to Ryder," Zendt was also
a champion, "More from the hidden menace of the real Doom comes it."

"If I could get away," said Ellison, "I'd take back the thing for
Ryder."

"It is my risk. I got into this thing."

"But why do you suggest taking Roger, Doctor?" Grover asked.

"Several reasons. First: he has proved that he is accurate in discerning
the correct interpretation of sounds, which leads to the next: he is
clever at photography and other scientific means of getting accurate
data. To explain that, let me say that with so much danger if it were
known that I meant to get into the temple, a secret way to restore the
Eye would be safer.

"There is a hidden way to enter the temple. I do not know it, but I feel
that in some way it may be connected with that Voice of Doom, and Roger
could photograph, enlarge his takes, study them, and with his sharp eye
and keen wit, could no doubt find the secret."

"A last reason," Mr. Clark added, "is that he can operate a
radio-telephone, as well as send wireless code. We might want the
former, if two parties, separated, needed to keep in constant touch. The
latter, short-wave sending and receiving, could keep us in touch with
the outside world--even with you, Mr. Mystery Wizard Brown."

Put that way, there seemed less to make Roger uncertain.

What an adventure!

"If you could spare that husky, loyal general assistant, Potts,"
suggested the doctor, "we could ask no better guardian for your cousin."

There was much to be considered; there was much apparatus to be designed
and assembled, including compact, tiny cameras, hand-operated generator
to supply current where electricity never had been used, light, but
powerful step-up transformers: there had to be clothing and other
traveling needs in sparsely settled Tibet to be planned.

Time, though, coupled with a spirit of eagerness, helps in such plans,
and it was soon time to say good-bye, to wave from the moving train, to
hear Tip shout, "At last we got everything coagulated. We're off!" and
to settle back in a parlor car seat until time to go into the diner.

Across America, and on the ship bearing the party toward the
International Date Line in the Pacific where one day changed to another
by the simple process of crossing the imaginary line--the way that the
astronomers had worked out to adjust Time to the sun's progress--and
even when they landed in China, only slight evidence had been noticed
that the effort to secure the gem was still alive in some one's mind.

Doctor Ryder felt that it indicated that the Tibetans had really been
the ones after the Eye; and the ransacking of a despatch box, in their
hotel room in San Francisco, he thought, had been the work of an
international jewel thief.

Roger, while they crossed the Republic of China from Shanghai, had
plenty to interest him, and so did Potts.

That loyal if uneducated guardian voiced his astonishment at the unusual
sights and experiences.

"No wonder they say these people are backward," he told Roger. "They do
everything hind-side-first. Men wear skirts and women wear pajamas. They
build a station where there ain't any railroad at all, and have roads
where there ain't any traffic to use 'em."

"Well, to them that is their way. They think our way is back-ways."

"It is all in the point of view," Mr. Clark took part in the chat.
"Everything depends on how you look at it. The moon looks far off if you
reverse your telescope, yet a star looks closer from the right end of
the same instrument."

"I don't care," Tip was stubborn about his idea, "They _are_ a backward
race. Look at that!"

"That" was a rickshaw boy, drawing his two wheeled carriage with two
American tourist women in it. The boy deliberately swerved and ran
across the street just in front of the automobile, the traveling
companions and Roger were using. The driver had to stand on his brakes.

"They think devils chase them, and if they turn right-angles and run in
front of something, _it_ runs over the devils that can't turn corners."
Potts was disgusted.

Other strange customs--strange because different from American
habit--kept them alert and amused as they progressed toward the place
where arrangements had been made for the party to join a caravan that
was on its way across Tibet bearing tea and other Chinese goods. It
seemed safest to go into the restricted territory as if bent on passing
through it. Camels, with great fuss and grumbling, swift ponies with
many whickers of eagerness to gallop rather than walk or trot, got under
way and Roger, swaying on his Ship of the Desert, bound, seemingly, for
the Kybur Pass and India, smiled as Potts found his curious steed
inducing a seasickness that made him prefer to walk a good part of the
time, unless the pace was too swift, when Tip rode and suffered.

As arranged, at one of the halting places, during the night, the
quartet, met by guides and bearers as arranged for by the caravan
leader, quietly forsook the caravan, and rode, on wiry ponies, into
darkness and a land over which brooded the mysterious, terrible
Himalayas.

Far away, in a city laboratory, with Roger's chum, Billy Summers, an
expert radio "op," Grover tuned a set, amplified, increasing output
strength; and then, as Roger, in the Tibetan night, increased his own
signal power as Tip ground at the generator, each knew that with the
other all was well. Yes. Just then!




                               Chapter 14
                             CAPTIVE ROGER


Across the Tibetan plain, with its sparse vegetation and occasional
small and always distant group of rude huts surrounded by the grazing
herd of the tiny community, the party made its way uneventfully.

Steadily the ground grew higher. Constantly the Backbone of the World,
the great, forbidding, brooding Himalayan range, was a larger part of
the landscape ahead.

The guides, through an interpreter whose English was almost minus, but
who could understand Doctor Ryder's pantomime and few recalled Tibetan
phrases, had agreed reluctantly that they would avoid settled parts and
keep away from villages. His hesitation was due, as was explained, to
the greater danger of being set upon by bandits, or rough peasants who
amounted to the same thing. Yet that experience came.

At dusk, as they ate tinned food and the natives laid aside packs, cared
for the wiry ponies and made camp, the chief guide discerned the
approach of a dozen riders, galloping their sturdy mounts in a cluster
toward them.

Tip, with a grunt, snatched at his revolver. Mr. Clark, almost in a
snarl, ordered him not to show it.

"We must be diplomatic," the man added; and Doctor Ryder agreed.

"Roger," he said to the excited, trembling young scientific
representative, "can't you get something ready that might startle them
or look like magic?"

Roger, in spite of his misgivings, thought hard.

"Come here, Tip." Together, conferring, they unpacked equipment.

As the silent, but menacing horsemen deployed and surrounded the camp,
the youth drew on, hastily, heavy rubber gloves.

Tip, not too sure that he ought to be so far from his charge, obeyed
stern orders to carry out Roger's instructions, and in the tent, sat by
the handle of the generator. The small electricity-producing unit, much
more powerful, though no heavier than an automobile battery-generator,
had its handle and flywheel geared at a high ratio, so that moderate
turning rate gave the armature its correct impetus for best results.

From it, unseen in the darkness that came on, a wire ran to a spot where
Roger crouched, apparently busy with cooking utensils.

The bandits dismounted, and the group advanced, completely surrounding
the white men, who wore the native coats of rough texture but who did
not attempt to disguise their race.

The natives of the camp were evidently expecting the raid, and Roger was
sure that either the chief guide or an aide had betrayed them.

It was too late to avoid the encounter and recriminations were not wise.

"You give all money," the interpreter told Doctor Ryder as the leader of
their adversaries spoke in guttural phrases.

"Tell him we are scientists, going to study the great rocks. Tell him
that we have no money, and bid him go, before we ask our young magician,
who is close in the councils of the Gods, to smite them."

The interpreter apparently gave the interpretation faithfully, from his
gestures toward Roger; but the man he addressed gave a harsh laugh.

He spoke to his men and they roared and shouted in mockery.

"Bid him go, then, and try his strength to capture that small youth who
cooks the broth that gives him the strength of the Mountain Gods."

As Clark gave the phrases, he glanced at Roger.

Probably, Roger thought, the man was afraid that he would fail at this
critical moment. Be afraid. Or show nervousness.

The bandit leader guffawed, and strode rapidly, and menacingly, in
Roger's direction.

"It's your move, son," Roger mentally admonished himself. "Steady."

To Tip he called, very low, "Get set."

Tip called back, "Say when."

The bandit strode close.

"Om, man-u, pad-mi, om," muttered Roger, using the prayer so familiar to
all Buddhists in Tibet.

The man paused, looking a trifle surprised at the sound.

Roger, upsetting a pan of water on the earth, rose, standing near the
wet space.

In words taught him by the interpreter, he spoke.

"What do you seek?" his phrase demanded, and his voice he kept very
steady, even stern.

"You!"

The man, depending on surprise, made a quick grab, as Roger laid aside a
fork and with apparent aimlessness, paying no heed--outwardly--took in
his right hand a big iron ladle to stir the boiling soup.

As if unaware of the plan to attack, he went on, "Om man-u pad-mi om,"
knowing that the first utterance had started Tip to whirling his
generator armature.

The man made a grab. As though turning, Roger maneuvered so that his
ladle was just where the man made the grab--but Roger was beyond the wet
spot on which the man stepped.

Stepped up to stronger voltage, carried along the wire fixed to the
ladle handle held in his rubber-gloved hand, Roger was immune to the
current that had better conductivity through the man standing on wet
earth.

As his hand closed on the metal, with a startled, frightened howl, the
bandit writhed and was convulsed, more by surprise than by any vast
voltage. It was enough to jar, not enough to harm.

But he could not let go.

"Cease firing," Roger called, amused as the man was contorted by the
tingling, nerve-throbbing current that he could not understand.

The others, standing with mouths agape, saw their leader fall back, in
awe, rubbing his arms. He spoke abruptly, staring at Roger
unbelievingly. Then he drew back, and discussed his experience in
guttural grunts and abrupt gestures.

Roger, knowing that the generator was still, stirred the soup
nonchalantly while the interpreter, on whispered instructions, put a
brave front on the situation and demanded that the group go away before
all should feel the stronger wrath of their super-man.

They did draw aside, conferring. But they would not go. They took their
mounts, but sat on guard.

Roger, eating with his companions, suggested that if they could
demonstrate some visual marvel, such as a picture projected onto a
light-colored tent side, it might frighten away the men.

The guides did not think they would be bothered, the interpreter said.
The men would not go. They would stay on guard, and by keeping the party
surrounded, not molesting for fear of more harmful acts, but still
preventing them from moving, the bandits would wait for instructions
from some one in higher authority. A messenger had ridden away.

Shortly afterward, while they sat around their fire of native fuel, they
saw, approaching, the messenger and another tall Tibetan who dismounted
and approached. He wore the recognizable garb of a Lama.

"Show me your magician," he commanded.

Roger, assuming a brave air, arose.

"Come," the man beckoned, "you will show me your wonders. I will show
you mine."

"Better go," whispered Clark. "He will take you just where we want to
get. Take Tip, and a radio, the battery set. And keep in touch."




                               Chapter 15
                            IN THE LAMASERY


If the urging of the jeweler and of Doctor Ryder seemed like sacrificing
Roger, they assured him that it was not so.

The lama, they declared, was interested in anything seeming to be occult
or mystifying or a use of hidden forces. His attitude was not menacing.
Rather, it seemed friendly.

And he was a lama from the very temple they sought!

"What a break!" Tip, whose companionship the man readily agreed to, as
Tip carried the portable battery, compact five-tube set, telephone
instrument and spare B. battery, spoke under his breath.

"This will coagulate everything, make it easy," he added.

Roger, somewhat excited at the prospect of going into strange
adventures, being "on his own," nodded.

The man's attitude was respectful and friendly. The bandits stayed
around the camp, but the interpreter said that if the youth satisfied
his companion of his abilities, it might free them, might even help them
to reach their objective.

The lama had evidently been at a village not very far away: they had
only to walk to that, and then, with much show of veneration for the
lama, their holy man or priest, the villagers furnished ponies.

Roger, mounted and riding beside his friendly captor, with Tip and his
apparatus on another pony and on a led carrier-animal, noted the tiny
prayer-wheels by the ascending roadside, saw the other lamas they met
with their prayer-wheels and prayer-papers, observed the reverent
attitude of the peasants herding cattle or grazing sheep, and felt a
renewed confidence in the outcome.

The lama could not converse with him, but the universal language of look
and gesture served very well between them.

In due course, after riding up steeper and steeper paths, into the
craggy, ravine-and-cliff torn mountains, they came to a great, dreary,
uninviting stone monastery wherein the lamas stayed, studying, praying
and conducting the strange rites of their religion.

"If you ask me," muttered Tip, scanning the looming pile of stone, "We
are a long way from the lab. What's all them little windmills for?"

"Prayer-wheels," Roger told him. "They say their prayers with them."

"Well if you think I'm going to end up by spinning one of them
whirligigs, you're wrong. Tell this bird I'm incontrovertible."

"You're what?"

"Incontrovertible. I won't change my religion."

"Not convert-ible. I see. Still the same old Tip, far though you are, as
you say, from Grover's dark-room. But they seem to look up to this man
who brought us. He's sort of bossy, too, and they mind."

They were made as comfortable as the rude conditions of the cold, harsh
life the lamas led would allow.

Roger was glad that Tip was not separated from him. They were both given
one cell, a gloomy, but not prison-like cell that looked out through its
narrow window over a vast, tumbled, fissure-creased series of crags and
ravines, cliffs and snow-covered peaks.

It was as though the Creator of the world had flung this wild mass of
rock helter-skelter, in a long backbone, to hold the world together.

Simple, not too palatable food was ungrudgingly served, and their
conductor visited them several times to see that they needed nothing he
could offer.

The radio-telephone, answered by Doctor Ryder, reassured them. The
bandits had been sent away by abrupt orders from another lama. Not a can
of food or a bit of apparatus had been disturbed or taken.

The communicating sets worked well, and things were not so bad.

The gaunt, silent, stern-faced lamas served them without comment or
objection; and Tip and Roger were allowed to roam at will through most
of the corridors, rooms, cells and even were permitted to attend the
chanting devotions of the men in a huge chapel-like place. But that,
they were certain, was not the "temple" because there was no Buddha of
the stature they expected, or with a spare Eye either missing or
replaced by an imitation.

But nothing advanced. Nothing happened. Days dragged by.

The explanation came when their captor, or host, brought them into a
sort of general community room, where he presented them before a very
sedate and reserved and cold-visaged old man. Roger, however, did not
feel any fear, because the man's eyes seemed to hold some deep,
broad-minded tolerance. He looked kindly.

To their amazement he addressed Roger in halting, but clear English.

"You come far."

"Yes, sir," Tip spoke first.

"You come for what?"

Tip hesitated.

Roger came forward.

"This man and I are with a scientific expedition."

"Have you secured permission to enter our land?"

"I suppose so," Roger, himself, was not too certain about the details of
that official permit that Doctor Ryder said he had gotten.

"You understand something of science?"

Roger admitted it, not boastfully.

Their things were all brought in.

"Show me, and tell me."

Roger, trying to use short words and simple explanations, demonstrated
the radio-telephone, and its purpose of distant communication.

He did not want to explain the tiny camera, and put it into the case
with the spare battery, pretending that it was part of the apparatus
therein. The watching chief lama and the venerable visitor gave no
special attention to it and Roger was glad. He had it in case they got
near the temple and he could try to discover, from its pictures, later
enlarged, how the secret way into the edifice, if one existed, was
manipulated.

Contriving to "raise" his other friends, by the set, Roger allowed the
lama and the other to hear the reply to his guarded declaration that
they were being well nourished, made much of, and so on.

When the men seemed satisfied and the paraphernalia of radio was
removed, the gentleman at the head of the lamas considered Roger and Tip
thoughtfully.

"Indeed great progress has been made in your America," he said, to
Roger, while the lama sat silent. "Even you, not more than thirteen,
surely, accomplish what would be wizardry to our own peasants--and yet
this Forbidden Land holds locked in her bosom the destinies of
tomorrow's science, and knowledge of forces that your America does not
dream of. It is a strange old world."

"Yes, sir," Roger agreed, not knowing how else to respond, then:

"How do you come to know our language, sir?"

"Your own sacred Book tells of the--is it not the Tower of Babel?"

"Yes, sir."

"And is there not the word that prophets, as fire descended upon their
heads, spoke 'with many tongues'?"

"Yes, sir----"

"We, in Tibet, have methods for reproducing many miracles--as they would
seem to you, for all of your scientific wisdom. Let me show you."

As though understanding what was to come, the lama approached, and under
the steady gaze of the other, seemed to assume a trance-like fixedness
of expression. Standing, his body was still rigid, but he did not sway
or totter or fall.

Presently, as Roger and Tip watched, knowing it might be hypnotism, but
still marveling at the produced result, they heard:

"I am in a great laboratory." And the man used perfect English, not even
slightly inflected as had been that of the other, "There is an office
with a pair of desks. At one, a woman typewrites. At the other, Grover
Brown interviews his staff, and tells what Roger has sent him by the
Morse code and which he 'picked up' on four stages of radio-frequency
and three audio."

It was almost weird, uncanny. Of course, there might be such a thing as
mind-reading--but----

"In the chemical division, a man, Zendt, experiments with tissue, and a
new--to him--process for causing a medicinal reaction by the application
of Ellison's sun-lamp.

"But here--Roger fails to tell completely of his mechanism. He forgets
to explain the tiny camera with which he hopes to discover a secret way
into our temple----"

If Roger's face was controlled in time, perhaps Tip's was not.

The older man smiled, a little wryly.

"That will do." He clapped his hands sharply. The lama, with a somewhat
dazed look, flexed his muscles and stumbling to a seat, collapsed on it.
Magic? Trickery? Roger had no time to decide.

"If you are so anxious to learn our secrets of the temple," remarked the
old man, "you shall have them. Indeed, you shall even hear----"

Roger grew tense as he paused and then finished:

"The Voice of Doom! Come!"




                               Chapter 16
                            THE IMAGE SPEAKS


With an abrupt change the atmosphere seemed to be charged with
electricity. Of course, thought Roger, trying to remain cool, it was
merely his fear of the outcome that made his nerves tingle.

There was no time for any choice of action.

Rising, the old man moved toward an arched opening at one side of the
stone chamber. Tip, fierce-eyed, loyal, beside Roger, realized as he
tugged at his empty holster that in some clever way he had been
disarmed. A glance behind him showed the mocking lama, holding his own
weapon. Tip gauged the chances of a leap, shrugged. It was useless.
Monastery attendants were at all the open doorways.

"Buck up!" he whispered.

"It may not be so bad," Roger tried to reassure them both.

They followed, as follow they must, down a long, echoing, empty
corridor. Far away, low, weird, they could hear male voices, deep,
rather disturbing in tone, chanting some uncouth succession of notes.

Their slow walk behind the aged conductor brought them constantly nearer
to the chant, for the voices grew louder.

At a doorway, heavily shrouded in lustrous woven velvet or other
drapery, the guide swung, and an attendant, bowing, moved the cloth to
one side. The chanting swelled suddenly.

Resistance was futile. As the guide moved aside, motioning, Roger, and
Tip after him, passed under the great stone door-lintel, into a large
square chamber full of the chanting lamas.

And at the end, in a niche, on a sort of raised dais, sat the huge
carved wooden image or statue of the Meditating Buddha or prophet of
their religion, and in its forehead glowed, in the flickering
torchlight, the great, green duplicate--it appeared--of the Eye of Om.

At first it flashed through Roger's mind that this was strange; but at
once he realized that, of course, they would have replaced the gem with
a substitute or an imitation, and would not tell many of the loss.

Thrust forward by the lama who had brought them there, Roger and Potts
were ushered down the aisle between rows of kneeling,
low-and-mocking-voiced monks or lamas, to the space below the great
figure.

Words in Tibetan, answered by hoarse responses from the crowd, seemed to
be some ceremony or invocation of judgment, in which, they sensed, the
two white people were the sacrifice or center of the rite. Standing
silently, Tip was watchful but helpless. Roger, too, kept an alert mind
but saw no means of escape.

"You seek to hear the Voice. You wish to know the secret."

The venerable man who appeared to be some sort of super-lama, to whom
even their former captor deferred, knelt and pronounced some low, weird
and long-winded invocation.

At his gesture they both knelt, submissive if not willing, and he bowed
his head to the floor and stayed that way.

All the rest were in similar positions.

And then, blood-curdling in its startling suddenness, after an interval
of suspense, there came, but not softly or in small volume as in their
recordings it had been, a scream that was as weird as the howl of a soul
in torment; and after it followed, louder, but duplicating, the
decreasing pitch and growing volume of the howl, roar and groan, that
ceased abruptly on a hoarse note.

Apparently, and they all seemed to believe it, the Image had spoken.

Certainly, to Roger, still able to be alert enough to trace sound, it
issued from the head or face, possibly the small, slitted mouth of that
statue.

"The Doom has judged," the old man told them in precise English, but in
a very formal and cold tone, "the judgment is pronounced. I am to show
you our secret and allow your science to prove its worth."

A mocking twitch took the place of a smile as he added:

"Or, from our viewpoint, its worthlessness."

As he spoke, with no sound an orifice opened in the wall behind the
idol. In its cavernous depths, dark and forbidding, Roger guessed that
the stone had withdrawn up or sidewise, or had turned on a pivot.

He and Tip, hesitating, were prodded gruffly forward.

Into the decreasing light they moved--were forced to move.

The darkness became abruptly intense. The noiseless door had closed!

Echoing still to their last footstep, the silence slowly became
complete.

"Science!" grunted Tip, "Without no scientific impediments."

"Implements." Roger spoke from habit, still too dazed to feel, with
completeness, the horror that must soon come.

And far away, the last exhalation of the "s" he had spoken was flung
mockingly back by echo, a hiss of multiplied duration, fainter as it
echoed to and fro.

Trying to hold calm, Roger felt an impulse to scream, to beat on the
callous stone, to beg for mercy.

Instead, feeling that Tip also must feel the dread he felt, he nerved
himself to be not only calm, but matter-of-fact.

"Well," he remarked, "We've heard the Voice and found the secret way.
And that's that!"




                               Chapter 17
                             BLACK SILENCE


Without looking up from the radio over which he was fussing, Doctor
Ryder spoke snappishly. His nerves were on edge.

"We ought not to have brought him."

"But he was so clever," protested Clark, "and surely if anybody ever
could interpret what that temple must hide in that queer sound, he'd be
the one. He interpreted claws on glass, you said--and----"

"Be still. Let me listen."

The doctor fidgeted, trying to tune, to amplify, to adjust knobs on the
unresponsive radio set.

"We had no intention of getting him into hot water," Clark said,
morosely. "We did want to get into that temple. The bandits were
unforeseen complications; but when the Lama came, I thought that for
Roger it would all be simple, once he got into the lamasery."

He watched a few minutes.

"Can't you raise even a whisper?"

"No! And it has been three nights. And besides we can't operate the
wireless, because you don't know code. Brown, in America, will be wild.
Our three days of uncertainty is nothing. He hasn't heard since Roger
left us, and that was a week before our last contact with him."

"Let me try. You go and turn the dynamo."

"I wish I knew more about it. I know precious little, come to find out,
whether it's burned out, or the brushes gone, or how to adjust these
things." The doctor relinquished his place, went into the tent.

At the tuning dial and control knobs, as he whirled them and almost
frantically called into the telephone transmitter, Clark worked.

In the tent his companion swung the flywheel over, and around, and then
stopped, groaning.

"Guess we are licked," he came out.

"You go back. We'll keep trying."

Doctor Ryder nodded.

Ten minutes of silence.

"I'm--sh-h-h!"

Clark tuned delicately, getting the "hang" of the controls.

Out of the receiving diaphragm issued a low, male voice.

"You will return to your America."

Desperately Clark swung the switch to the sending side.

"Who are you? Where is our boy? Roger? Is he there? Is he----"

"He is gone. The Voice of Doom spoke his sentence. He has learned the
secret of the hidden darkness."

"We'll have a hundred thousand American troops in your darn country if
that boy has been hurt----"

The other end of the transmission mocked with a hoarse laugh.

That was all.

Doctor Ryder, informed, looked defeated.

"And all for a tawdry jewel. And we still have----"

Clark motioned for silence, trying desperately, vainly, to raise a
response from the dead ether waves.

They retired, at last, because with the glowering clouds hanging low in
a star-obscured sky, with possible guards in sight, they dared not make
a move.

Discussion had been fruitless. They had drawn only blanks in their
search for a course of action.

Clark, lying on his cot, tossing, got up.

"I can't sleep. I'm going to walk around--see if I can think up some way
to find out about Roger--and that man with him, too, of course, because
what happens to one will happen to the other."

He went out into the somber blackness of midnight.

Walking did not keep him from brooding, nor help his brain to do its
task.

He sat on a large tussock of dry turf.

"For a tawdry gem!" he muttered.

A slight sound made him leap up, revolver drawn.

Had it been the ever-blowing gale, stirring something? Or some fresh
menace, some creeping creature, some vindictive priest, who had made
that tiny sound of a scraping shoe?

"Who's there? Speak or I'll fire!"

He knew no direction to shoot in. But the light might disclose
something. He raised the weapon.

"Mr. Clark, don't----"

"_Roger!_"

"In person, and not a ghost."

In a heavy sheeps-wool coat, shaggy and rough, the figure came to his
side. His grip of the young hand was sincerely strong.

"Quick!" Roger gasped, "give me the Eye of Om--I can exchange it and get
back and we can go before they discover me."

"Where have you been?" as they walked fast toward camp. "What happened?"

"They tried us, and the Voice of Doom sentenced us, and they put us in
the chamber behind the image. But we can't stop to talk."

"Are you all right? Is Potts safe?"

"Yes. Yes. Hurry!"

"Let me go with you."

"Only hurry, and bring the Eye."

Dashing into the tent, scattering explanations to befuddled Doctor Ryder
as he broke apart the small secret compartment in a bedroll and got the
gem, Clark met Roger and handed him the stone.

Instantly Roger fled into the darkness.

When Clark overtook him he saw Potts holding two ponies. Sending Tip to
camp, the pair mounted and galloped away.

"It was easy to find the secret," Roger said as they made a quick ride
toward the distant cliffs, "Tip helped me keep my head. We figured out
that somebody worked the Voice, and it was louder than human sound. We
were in a tunnel. It sloped downwards. It seemed as though the Buddha
image had howled. That meant a way to get into the image or open a port
from the tunnel to it. Phonograph records wouldn't have been their way.

"The wind always howled around the lamasery, up so high. From what we
knew about acoustics and how they shaped the old phonograph horns to
increase sound amplification, we worked it out that we were in a sort of
wind-tunnel or horn, and it didn't seem that they opened any rock at the
image or we would have heard it. If the far end of the tunnel opened,
and wind howled in and through the hollow image, it could make those
weird howls, high and low, moans and screeches. So we followed the
tunnel down, and by using Tip's pencil flashlight we located a lever,
and risked making the sound. But we got out."

By reversing the method, he and Mr. Clark also got in, and with the
older traveler's wisdom they found the trick of getting into the image,
and saw that when the way was closed, the tunnel did not make it howl.
Also, from the eye-places, they made sure the temple was deserted, and
soon enough the change of gems was complete and later, blocking the
lower door lever with a wedge of stone, they prevented pursuit from that
direction and eventually reached camp safely. On the way Mr. Clark
discarded his now useless Eye taken from the prongs, and Roger, at last
safe, with a plane radioed for, slept and dreamed that he was being
awarded a medal "for 'sound' wisdom."

"After all," he said in his dream, "my deduction was 'sound'."




                               Chapter 18
                      A LETTER ROGER HAD NOT SENT


Reunion with Grover and the laboratory staff, was, as Tip put it, "the
best part of assimilating Tibet." He explained that he meant "taking in"
the country.

Roger agreed with his spirit if not with his choice of words.

It did give him a little twinge of dismay, a slight blow to his vanity,
to discover that during his absence Toby Smith had been put to work in
the stock and supply department. Toby Smith, who had sold them the
priceless emerald Eye of Om for a movie camera!

At once Roger pushed away the feeling of disappointment and did not let
it become envy. This world and its work, he realized, had to keep
moving, no matter who dropped out. Instead of being hurt, he dismissed
his emotion by telling himself that it showed that any person, no matter
how able, could be replaced. The important idea to have, he told
himself, was that if one made one's self so capable as to be missed when
away, more than that could not be done.

After a while he was glad he had not cherished mean feelings, for Toby
had not replaced him. He had merely done his best. Roger, as the staff
soon let him know, had been missed for his competent way of handling
needs, keeping everything neat and available, and being cheerful and
useful under any circumstances.

"Am I glad you're back!" Toby hailed him. "This chemistry is too much
for me. One day Mr. Zendt asks for me to pack some frozen H--two--O
around a can of stuff. How'd I know the man wanted ice?"

"It takes study to understand the chemical symbols," Roger said.

"Yeh. And they have so many things that sound safe, and they're dynamite
in disguise. Like a guy wanted some citric acid, and I got picric acid,
and I spilled some and was swabbing it up with cotton, and I used it to
swab up something else--I forget what, but when I was going to chuck it
in the furnace, they almost had a fit. It had turned into lyddite or
some other sort of explosive. Looked like the same cotton to me."

"I never could get them sodium calorides straight, neither," Potts took
up the complaint against chemistry's "cheating" symbols. "They say it's
made out of a gas in the ocean. And the ocean's _water_, and here comes
gas, and they put metal, mind you--sodium--on top of it, and it turns
out to be common table salt."

"It's sodium chloride," Roger corrected him, "not caloride."

"And they talk the craziest lingo, here," Toby insisted. "Mr. Ellison
asked for motor brushes, so I looked, and the only brush I could find
was what we sweep up dust with, so I took that. Was he mad!"

Roger's return to his duties in charge of stock was acceptable!

Grover, when the celebrations were concluded and routine had been
resumed, sat down in the private "thinking den" as Roger called his
office, and chatted.

"We have quite a few new interests," he gave information. "Mr. Ellison
has perfected his speed camera with stroboscopic lamps so strong that
they beat sunshine. He can't use a shutter: nothing mechanical can be
made to work as fast as he wants it to. So he uses alternate flashes of
the lamp, and his film runs so fast past the aperture that not even
daylight fogs it. Of course you know he was busy with it, but you don't
know that he has succeeded in perfecting it, and is studying some
amazing chemical and other operations of Nature.

"Mr. Zendt has brought in rather an unusual man for us. He was an
astrologer--a man who reads 'destiny' in the planets by making a chart
of the zodiac for the moment a person was born. He used to sell his
'fortunes' at so-much a 'destiny' on a Coney Island boardwalk.

"Now, though, he has turned scientist."

His interest, Grover explained, was in studying in a scientific way the
reactions of cells, tissues, plant and animal life to various rays of
light, heat and other frequencies of vibration. His theory was that as
the sun awakened life in the Spring, as the moon partly governed tides,
so other planetary vibrations, reflections and modifications of sun
rays, made changes in chemical constituents of cells; and if plants were
made up of cells, and if animals ate the plants and in their own bodies
modified and incorporated these cells, then the rays must act on animals
also; and from that, to saying they influenced the bodies of men in some
way was not a far step.

With telescope, vibration-recorders, ray-filters, lamps and spectrum
devices he was carrying forward experiments in the room next to Roger's
supply department.

"You will probably have to help Astrovox--he says he is 'the voice of
the stars!'--with his apparatus," Grover added.

The most interesting point to Roger was the fact that nothing new had
occurred in their mysteries.

"I guess everything is settled," Roger declared. "With the Eye in its
place, there isn't any more danger for Doctor Ryder, and I saw Mr. Clark
exchange the one he had for it, and even helped.

"The big jewel was in a sort of depressed place, with prongs to hold
it," he reconstructed the event, "and we found a way to make the prongs
loosen, by working out that the gem had to be put in, and it was too
finely cut to enable them to hammer the prongs down, so we hunted for
some secret springs, and the Buddha image had a finger that could be
bent back, and it turned the prongs outwards, so we substituted the real
gem and then set the prongs, and all was well."

"I am not satisfied about the business, though," Grover stated. "In the
first place, although we have explained a good deal, and what you say
about replacing the gem is true, some of the manifestations we
experienced are sticking in the back of my head. They seemed so--so 'out
of character' with what Tibetans, or gem thieves either, would have
done."

"But if the gem is replaced and there isn't any more need for the
'manifestations,' we won't have any more, and we can forget the whole
thing."

Grover smiled.

"Suppose that a series of experiments were going forward to find a more
durable resistance wire for rheostats," he suggested, "and the firm that
commissioned us said to drop it, how would you want to do?"

"The same as you always do in such a case, Grover. Go through with it. I
see your idea."

The sound of the Voice of Doom, he asserted, was explained. There really
had been such a natural phenomenon, caused by wind let into a tunnel and
making the sounds through the shape like a whistle in the tunnel and in
the Buddha image.

"But how did it get on the records?"

Roger was equally unable to answer that.

"Besides," Grover insisted, "those priests are curious folk. You saw the
gem replaced, and to white people that would end the need for stalking a
culprit; but they seem bent on punishing people."

"'Seem'?" Roger caught the present tense.

"Why, your own letter says so."

"My--which letter?"

"The last one you wrote. It came yesterday."

Grover drew from the drawer an envelope postmarked, as Roger saw, from
Bombay. They had come on down the caravan trails, until they had met an
English airplane that had been arranged for. It had "set down" on the
plain. In that they had flown to India, leaving their stuff to be
brought along by the next caravan and shipped home.

The address seemed very like his own handwriting--close enough to have
fooled Grover, evidently.

And yet--he had been on a packet boat, bound for Europe, on the day
shown by the postmark.

Quickly, startled, he opened the letter. In the same close imitation of
his exact, clear script, he read:

                                                 Bombay, before sailing.

  Dear Grover,

  Well, we are homeward bound now. At the cost of a radio and camera
  left in the Lamasery of the Holiest Ones, I abandoned them. So far, no
  event has come from my visit there. But of course with the Eye of Om
  stolen, the Guardians of the Eye may strike. In haste, to catch the
  mail, I am,

                                                         Affectionately,
                                                            Your cousin.

Roger looked up.

"But the Eye of Om was replaced! I helped."

"Then why did you write?----"

"I was on a boat when that letter was posted, Grover!"

He bent forward, earnest and eager.

"Who?--And the Eye was _not_ sto----"

His lips closed. His face changed.

He remembered something.

It was unjust to let it mean anything. But----

Why had Potiphar Potts gone back to that secret tunnel?




                               Chapter 19
                         DISQUIETING DEDUCTIONS


Of all his loyal staff, most dependable, sincere and trustworthy was the
handy man, Potiphar Potts. Roger knew that.

Honesty compelled him, all the same, to connect the fact stated in that
mystifying letter with a fact that had not been important when it had
come to him.

Potts, on that memorable night, holding the ponies while Roger had gone
to Clark, had, as they discovered on their safe return, gone on into the
camp.

When they had gotten back, to report to Doctor Ryder the substitution
for the false Eye of the one they had brought, Potts had seemed uneasy,
though Roger had accepted the man's own explanation.

"I'm worried about our idea of you leaving the wedge in the thing that
works the rock door," he had said, "it sounded good when we made the
plan. If we wedged the mechanical levers, we said, they couldn't get out
that way and chase us or anything."

Roger said he still thought it a sound idea.

"I don't, now," Tip had declared. "They may not go in at the temple to
see about us for days, and what difference would it make whether the
lower end is blocked if they did come down that way? They'd go back, mad
as hornets, and we _would_ be in for it!"

If they had left everything as before, Potts had insisted, anyone using
the lower entrance would suspect nothing, and might not even know they
had come out that way.

"I'm going back and fix it the way we found it," he had said.

Loyal, honest, faithful Tip! Why, Roger wondered, did his mind persist
in telling him that Potts had stayed away from camp a long time and why
did he associate that with the present threat?

Truly enough, he _had_ actually seen--helped replace--that gem. With
equal sureness, the note said that the gem was gone. It was no trick of
deduction to assume that the note had been prepared by the lamas, soon
after he had escaped. They had shown how clever they were at pretending
to be able to read his mind, telling about the lab.

He recalled that he had kept a record in a booklet, of radio
conversations from his portable set in the lamasery to the camp set.

They had specimens of his handwriting. A clever man, forging for the
purpose of conveying a threat, perhaps planning some harm to Roger on
the trip home, had certainly, to all appearances, made the note.

Well, his mind ran on, if they had been so sure that the gem was gone,
and if they had supposed that in vanishing he and Potts had taken it,
the note would be their natural Tibetan way to account to Grover for
anything that might have happened to Roger later.

Nothing had; but the note had been despatched, with the probable
knowledge that the letter, by mail, might get a faster trip, a more
direct route than the travelers might use. It had been so.

Who besides Potts could have known that the genuine gem was in its
place?

Not the camp people; and they did not know the secret of the tunnel.

Neither Clark nor Doctor Ryder had left camp for any protracted period.

"But," Roger remonstrated with his stubborn idea, "if Tip had been
tempted to take it, the Eye of Om was available all the way there."

His prodding deduction shook that off. Potts would not have dared to try
for it on the way to the temple. But--after it was supposed to be in
place, so that his party would not know of its abstraction!----Roger
fought, but so did his insistent suspicion.

He decided not to tell Grover.

"I--I hesitated because--well, it came to me that somebody else _could_
have taken it, later. We got away from that locality as fast as we
could, and met the 'plane the next day, after I had radioed our agreed
signal to a British aviation field in India to despatch it."

"We can find out something by photographing the fingerprints on the
note, and so on, with routine procedure," Grover dismissed Roger's
poorly explained hesitation. "Suppose you let Tip do it."

Roger agreed eagerly.

A fine way that would be to see Tip's reaction.

Roger took him the note with Grover's orders.

"Gone? The Eye--gone?"

Surprise seemed genuine. And Tip--Roger felt sure--was too slow of wit
to act so cleverly as to seem innocent under this surprise.

"Glory-to-Grandma!" Potts gasped, "And--I--went back----"

"But you wouldn't take it!"

Potts made a wry face.

"Maybe--maybe--" he seemed to find it hard to go on; but he forced his
lips to form the sounds sent up by his vocal chords.

"I declare, Rog', if I took the Eye, I didn't mean to."

"If you took it--how could you help meaning to?"

"I picked up what I thought was the subterfuge----"

"Substitute?"

"Yes. Thrown away by Clark, I supposed. Like Toby done before."

"Where is it?"

"I--uh--why--tell truth, Rog', I--I thrown it away. Back in Bombay. I
figured it wasn't a safe idea to keep it, after all."

So there it stood!




                               Chapter 20
                              GHOST VOICES


Roger's mind was more at ease. He had seen Mr. Clark pocket the gem for
which they substituted their Eye of Aum. Outside the rock door as they
emerged from the fissure leading down from the temple, he had seen the
man's hand pull it from his pocket and fling it away.

"That's no good," the jeweler helping Doctor Ryder had chuckled.

Definitely, in Roger's mind, Potts had found that cast-away imitation.
He had not gone back through the tunnel!

"Exonerated," he said, cheerfully, and they brushed a finely pulverized
compound over the note, seeking to bring into relief the possible
finger-prints thereon. Several faint smudges showed, and Potts made a
photographic exposure, also using chemicals, with other takes, to bring
up possible marks, erasures and so on.

Roger left him at his work, at a call from Astrovox, the scientific
student of planetary vibration who had been a side-show astrologer.

Joining the plump, bald-headed little man, close to sixty, whose
deep-set, shaggy-browed blue eyes twinkled with inward cheerfulness,
Roger helped him rig up his seemingly crazy idea of a
vibra-spectra-telegraph-o-scope.

That was what Roger mentally named it. The man wanted to catch the
possible vibrations of higher and lower frequencies than light range. He
also wished the various colors showing in a star ray to tell whatever
spectrum bands it might contain. Besides, he had to hold this apparatus
trained on a desired planet or star, by use of a mechanical movement
that enabled him, through a transit's hairlike "sight" to follow a star
as the earth revolved. Furthermore, he wished photographs and a sort of
seismographic tape recording of vibration frequencies.

The nine-power telescope he had to be satisfied with was set up to poke
its outer lens up through the skylight over the supply room.

All around the smaller, adjoining, partitioned place formerly made
notable because of the vanishing rats and the strange voices, he had
cages of mice, squirrels and rabbits, under rays from electrical, and
other forms of vibration. In hot-house "frames" or small beds under
glass he kept living plants, with color-filters straining the light
playing on them, to test reaction to heat, light and color.

One bed, under a brownish glass, Roger noticed, had thin, stringy,
sickly vegetation in it. In one under a short-wave irradiation
treatment, plants thrived.

In tiny flat, glass-protected trays, specimens of cell-cultures in
tubes, and sections of living plant tissue were being exposed.

"Guess we'll have to clean out the far corner," Astrovox suggested, "I
dumped all the wrappings there. Might start a fire."

Approaching to help, he finished his sentence with a chuckle.

Roger nodded, and gathered up the papers, making a fine rattle in the
process.

A glow-bulb lighted in the interconnected tell-tale panel as a small
bell rang. Roger, glancing at the panel, saw that the summons was from
the electrical division downstairs. He went to the head of the steps.

"Want me?"

"Yes," answered the voice of Professor Millman, electrical engineer.
"We're going to make a flat-table recording. I don't just see where we
get power for the motor from."

"Right down close under the recording machine table," Roger called down
his information. "You'll see an outlet set into the floor."

"Oh--thanks, yes. I see."

Roger went back to help Astrovox.

"Can't risk it, with all the chemicals, and combustible stuff," he
answered the former phrases of the old astrologer.

"Not with Neptune, the planet, in opposition to Saturn and with Mars
opposing Uranus," the old man chuckled.

Roger looked as if he did not see the point.

"In our belief that the planetary positions influence chemical
reactions--and all life is chemical, or, at least electro-chemical," he
was told, "we use the known planets as symbols for forces of nature.
Saturn, you might say, stands for cohesion--or, better, say for
crystallization, because Saturn makes gravity possible, makes density in
our earth by cohering its quintrillions of atoms.

"Mars we could say is a symbol for the combustion engendered by fire,
the same as Uranus is, in a way, a symbol of explosiveness, and Neptune
seems to represent a sort of disintegration, diffusion and slow
separation of atoms, not by explosion but by attrition."

To Roger it was all pretty much like Egyptian hieroglyphics but the man
seemed to be talking what he considered sensible phrases.

"Let us say that we place a pellet of putty between two machines, one
engendering a force like repulsion; the other giving quick, and very
high-frequency stabs of current toward the other. The answer might be
that the pellet would explode or fly into its atoms.

"But," the old man went on, "The force of cohesion would hold our earth
together in such an experiment, though the volume or size of the tiny
pellet would be too little for it to act on sufficiently to keep the
form together. That, in a way, is what so many people misunderstand when
they talk about astrology. Properly used, correctly interpreted, it
enables us to understand our reactions--emotions----"

Roger was in the next room, loading the papers on the dumb-waiter to
send to the cellar. As he came back, gathering up more, Astrovox, as if
he had ranted along on his favorite topic without ceasing, said:

"--fire." He stood up. "Where were you? I was telling about Mars and
Uranus exploding things and starting fires."

"I have to work."

"Yes, that's so. Well, this is your last load."

Roger gathered the great heap of heavy wrapping paper, and left him
shifting one bed of plants from under a deep ruby glass so that they
would be exposed to a pale green color filtration.

Going down to remove the papers from the dumb-waiter, Roger saw Mr.
Millman finish recording the multitude of gyrations of a sparking motor
shaft which Mr. Ellison was photographing with his camera.

"We are going to count the sparks," he told Roger, "just to check up on
the speedometer attached to the flywheel, which Millman says is
off-count by hundreds of revolutions to the minute."

"I'll take the record up and have it made ready for a slow playback. I'm
going up anyway."

He turned it over to Potts as the note had been thoroughly revealed in
all his exposures, and had shown no identifying finger-marks.

Roger went back to Astrovox, and became deeply interested in the
latter's plans for night study of the spectra of stars.

"I wonder if your cousin would arrange for one of his men to stay part
of the night with me, to take down my data?"

"We can set up a dictograph, and let you talk it onto a record."

"That would do."

"Or--we could mike down from here to one of our magazine-recorders that
puts a new record on the spindle of the turntable when the other has
been used up. That would run you for hours, if you'd stop it in between
dictating periods."

The thing was arranged and Roger, before going home, demonstrated the
mechanism and was sure the old man understood its operation.

Because of the threat implied in the forged note, Grover gave Potts
instructions to transfer from Doctor Ryder's rooms the mechanisms he
wanted to have installed for Roger's protection. With a changed switch
operated only from inside the room, the former ease of operation by
others, he thought, was eliminated.

Roger, tired by celebration and resuming work, retired early, being sure
that his switch was set, his room theoretically a sealed place.

Sleep came. Rest, though was disturbed by weird dreams.

Sometimes, he knew, dreams had outward causes stimulating them, as
happens if a draft on exposed limbs makes one dream of riding on a sled
and falling into a snow bank in howling wind.

His dream of a burglar, as he awakened and looked rather fearfully
around, made him grin, though.

That room had been sealed by no one other than himself!

But a low, humming whine made him certain that machinery was in
operation--the hum of the recorder motor. He located it. Proved it.
Shutting off the device in case some jar had started it, he went to test
his door. But he recalled that the motor still ran.

To his dismay, the door was not merely unsealed. It stood ajar.

Suddenly, startlingly, from behind him, his table radio spoke, in a
thin, strained, bizarre cry.

"Fire!" and he heard, faintly, the crackle of flames.

Then an uncanny silence, dreadful by contrast, came.

He spied around the hall. It, too, was silent. He tiptoed down to the
library, telephoned the laboratory, and got no reply.

Once again--something was wrong--in two places! He must go to that
laboratory. Grover should have answered--or Tip--or Astrovox!




                               Chapter 21
                                TRAGEDY!


Half way to the laboratory, Roger pulled up in his stride, half ready to
laugh at his stupidity. A joke? Of course.

Potts, on Grover's instructions, had made the room installation. To "get
back" at his chum for the suspicion about the Eye of Om, the handy man
could have made that "Fire" cry on a record, could have known how to
break a light beam. He, alone, could have prepared the impregnable place
so that it might be entered, it seemed to Roger.

A recording, he also knew, was the other end of a reproduction. To print
a sound-track on a disk, one used a microphone; its diaphragm sent
vibrations through a selenium cell and other apparatus until it actuated
the recording diamond: to play it back, the process was reversed.

The use of the diamond, instead of a smooth reproducing needle on a
hardened surface, _could_ cause that high, thin, scratchy voice.

"But Cousin Grover was not at home," his mind prompted, "and the door
was open, and the light would not work. The lab. telephone was dead,
too!"

Perhaps Potts had tried a joke; but it seemed as if it had turned into a
warning, a summons; because, when he reached the building, the door was
not secured, no protective beam had been set; and in the main office, he
smelt the sharp, acrid odor of burned powder.

A gun must have been fired in there, he reasoned. By whom? For what? His
mind raced to terrifying impressions. Explosion! Shot!

The place was jet-dark. As he investigated he decided that odor was
strongest close to the interviewing desk, pungent enough to choke him.

Into the larger main room he made his way, finding the powder odor was
less strong beyond the main office as he switched on lights and took
broader observations.

On the large desk used for interviewing visitors he saw that the framed
photograph of his aunt, Grover's sister, had been knocked down, and lay
on its face. An inkwell, in a pool of black on the floor beyond the
desk, was shattered into large fragments, and tiny bits.

He stood still, and shouted.

"Tip! Tip! Potiphar Potts! Tip!"

Getting no answer he raced across the chemical section to the man's
small quarters.

The bed had been used, its covers had been thrown back, as if in haste.

No Potts, as once before, stood tied to the bedpost.

The room was empty.

He shouted for Astrovox, feeling a strange desire to laugh at the sound
of the name when it was shouted. "Astro--_vox!_"

He called for his cousin.

Then, with every light going, in spite of queer terrors, Roger made a
thorough search of the lower floor.

That brought no result. Nothing seemed to have been moved and as far as
he could tell the safe was all right and the device that now made it
sink into a channel in the cellar, so that a steel plate could slide
over and make it impregnable, seemed to be in working condition.

Reluctantly, forcing his dragging feet, he crept upstairs.

No one was in sight. The old star-gazer was gone also!

Roger stood, uncertainly glancing around.

Had this been tragedy? A shot? At whom? Where were the rest?

Of a sudden the threat in the note became his uppermost thought. Had
someone--or something!--drawn the rest away, and lured _him_ there?

Roger, nervously, glanced around him.

The innocent squirrels and rabbits and mice curled up in their temporary
respite from the ray-baths. The machines set up earlier hummed quietly,
recording, slowly moving the telescope, casting spectra of a star's
light in bands of greenish-brown, yellow and indigo on a flat
paper-table. Everything seemed innocent enough.

But where, he mused, had the scientific star-student gone to?

Where was Cousin Grover? And, above all, where was Tip, one out of all
of them who ought to have been on duty, if not asleep.

Roger glanced up at the clock.

Not five, but two, was the hour toward which the smaller hand was
dropping as the minute hand marked the quarter-of.

It _had_ been "fire" that his record had screeched at him.

But there was no fire here!

Roger began to feel somewhat like a person flying in an airplane for the
first time, seeing everything else swinging beneath him, and feeling no
movement himself.

It made him sickish.

"Am I out of my mind?" he asked himself. "Is this a dream?"

There must be some loose end of this amazing situation that he could get
hold of, to reel in the story and steady his rapidly failing sense of
reality.

The sound-camera! It had been running perhaps, till its roll of non-flam
film was done. It might tell him something.

Feverishly he got pyro, acid and the sodas into the developing water. He
did not stop even for distilled water but took tap fluid.

He immersed the hurriedly rubber-wrapped celluloid.

As it stayed the required fifteen or eighteen minutes, he went over the
lab. again, finding no more than before.

He took out the roll, dipped it into hypo-acid fixing solution, and
impatiently watched its opaque yellowish high-lights slowly dissolve and
lose the un-needed silver salts, to clear into transparency as grays and
blacks became more evident.

Hastily washing the film, he unreeled an end, held it up under a light,
to see if the sound-track at one side carried any shadows.

There was a recording!

Feverishly, forgetting his terrors, he raced to the projector in the
screening room. Carefully in spite of haste he threaded the wet "stock"
over the sprocket, down through the film gate, over another sprocket and
clipped the end to the take-up reel. He snapped on the light.

At proper speed, and sorry that he must harm the wet emulsion, but eager
to hear its story, he ran his find.

The picture was that of the upper room, narrowed down onto the various
activities of the old star-reader. The first was a take of his rabbits
as they scampered about under a change of ray-lamps.

Then came the brief time-exposures of tabulations, preserved thus.

But nowhere, except for natural sounds, the squeak of mice when a
movement of a high-frequency ray cast it upon them--the chatter of the
squirrels--ordinary lab. sounds of moving feet and muttered words by the
old man, did Roger hear what he sought--enlightenment.

He was near the end of the reel, about to give up, when his ears sent a
message that snapped his muscles into taut tension.

"Hear me. I am The Voice of Doom!"

He saw, in the picture, the astrologer wheel and stare. He saw him turn
and run out of view.

Then, with scream subsiding in moan, the Voice of Doom repeated its
earlier moaning, ending in the grind and sudden cessation.

The film, unnoticed, ran out of the gate, and the magazine clicked to
the slap of its still revolving free end.

Roger let it run on. He had discovered a strange clue!

Once coming from a deserted room, and once spoken on a record that had
been considered blank, and then a third time from a record that had been
set to catch sound in Doctor Ryder's home, had come that same Voice of
Doom, the identical moaning and grating.

In reality, in the heart of Tibet, Roger had also heard that sound.

And in Tibet, the rock that cut off the sound had made no noise as its
counterweight allowed it to shut out the wind that made the moans as it
howled across the Himalayas and up through tunnel and whistling Buddha's
hollow cavities!

Even as he made his startling realization, Roger heard a bell.

It came from the office telephone.

He dashed down the stairs, cutting out the projector as he ran by.

"Hello!----"

A voice came, thin with distance.

"That you, Rog'?"

"Yes. Tip--at the lab. Where are you?"

"Hunting Grover."

"Where did he go?"

"To find the star-man."

"And why did he leave?"

"He was--took!"

"Do you--does Grover--think he was--was in danger--hurt?"

"We don't know. You stay there. I'll keep in touch."

The connection broke off sharply.

From behind him a voice addressed Roger.

"Follow me--and be silent!"

There stood the Lama from the Tibetan lamasery. Two others, also.

Wordless, helpless, Roger moved: they closed in behind him.

The night swallowed the quartet.




                               Chapter 22
                     WHAT HAPPENED TO THE EYE OF OM


They allowed Roger to lock up the laboratory; but he had not been
permitted to re-set the rays or other protective devices.

That did not concern him overmuch. Roger knew that the safe protection
was a separate circuit from those he had cut out when he had unfastened
the door on arriving. Besides, he told himself triumphantly, he had
recalled the camera fixed in the small decorative panel over the
interviewing chair, so arranged that it would photograph a short time
exposure of the office and of anyone there. Used to make records of
visitors on their arrival with new propositions, as well as a night
protection and recorder for the office, it had been operated by Roger,
with good presence of mind, when his captors had entered.

Whoever came there later would be able to develop the picture he had
left recorded. He had not used the continuous mechanism, but his one
photograph would reveal him and the Tibetan trio.

A taxi, taking them to some unknown district, was further cause for
triumph. The taxi, from a nearby stand, had been used before by the
laboratory people. Its driver knew him, though he gave no sign.

Roger meant to act in such a way that the man, discharging his fare and
being paid, would suspect something wrong, return to the laboratory, or
consult the police.

At a quiet, small hotel, the machine stopped. Roger, with hands clasped
behind his back, made gestures; waggling his fingers to attract the
taximan's notice, then touching himself and clenching his fist.

"Thanks, feller," the man took his fare, and added, to show Roger he was
"wise," "That science place brought me a good tip. Guess I better go
back and see about more good fares there."

Instead of causing a commotion as they passed the drowsy office clerk,
Roger let things stand as they were, and was taken up to a quiet suite
where the two guards placidly watched him while the Lama telephoned from
another room.

After a while, returning, the man ushered in--Grover.

"How did you come here?" cried Roger.

"So they got you."

"But you shouldn't----"

"I didn't exactly walk into a trap, Roger. The Chief of Police knows
where I came in answer to a note handed me while I was trying to trace
Astrovox. If I do not telephone within an hour, somebody will come to
see what's what."

He explained what Roger had not known (after hearing the strange events
of the opened door, the screeching table radio and seeing the
smoke-filled office).

"I stayed to watch Astrovox make spectra-graphs of color bands," Grover
explained, "sending Tip here to be on guard. An excited call seeming to
come from him brought me to the house just as a note he got started him
to the laboratory. We passed, not knowing. I found your safeguards
apparently working, and returned. Potts was trying to reassure the
star-gazer who had heard that Voice of Doom. But Tip was frightened
also. We sent the astrologer to lie down on Tip's bed, while we
investigated. He came back to us after a few minutes saying he was too
much upset to stay there. He thought the Tibetans had involved him in
some manner."

Tip, it appeared, had agreed to go along to be sure the man got going
and reached home safely.

Tip had bidden him wait, in the chemical section, while he went to his
own room to get a weapon for safety's sake.

"I suppose he must have heard something or started into the office,
Roger. At any rate, suddenly, we heard the shot. I was down those stairs
in a bound, and beat Tip by ten feet getting in where the smoke still
hung in the air."

"It was strong when I got there."

"But the office was empty. I told Potts to stay, and ran out. A man,
strolling, had stopped. I asked if he had seen a man go out and he
pointed up the street, and like most of those night-prowlers he tried to
avoid the light and hid his face with his hat brim. He was fairly short
and stoutish, but it wasn't Astrovox. I ran, and thought I saw the
star-gazer further along; but it was not our man. I suppose Tip,
worried, came to look for me. You say the wires were silent."

He was stopped by the arrival of Tip who had been lured, as he had, by a
note delivered by a boy; and almost on his heels came Clark and Doctor
Ryder, fuming and puzzled and anxious.

They were given no time to exchange words. The Lama spoke:

"We want the sacred relic, the Eye of Om."

"It is in the Buddha's head," Roger said earnestly, "I saw this man put
it there."

"He tells the truth," Clark declared.

"To prove it," Roger hurried on, "the prongs work open when you press
the Buddha's third left finger straight in and then back."

The Lama stared.

"And to furthermore prove it and make it inadmissible----"

"Incontrovertible, Tip means," said Grover.

"--I went back, later, to take wedges out of the lower lever, after we
beat your trick tunnel, and picked up the Imitation that Rog' tells me
Mister Clark throwed away. I carried it as far as Bombay, and figured it
wasn't worth anything anyhow, so I left it in the waste-basket in the
hotel room."

The Tibetan lama stared at him sternly.

"That was but an imitation. It was the one taken _out_ that I demand,
from the boy who must know where it is."

"But--I tell you!" Roger was earnest, "I saw Mister Clark exchange the
false one. And he dropped the one taken out into his coat, and when we
got out of the tunnel and closed the rock, he threw it away, saying it
wasn't any use. Tip, here, found that!"

The lama shook his head.

"The Eye of Om is not in its socket!"

A sudden thought came to Mr. Clark. With a cry of dismay he told them
his startling idea.

"It must be that in the excitement, meaning to exchange the imitation
for the real--to put back what rightfully belonged there and protect my
friend, Doctor Ryder, I must have mixed the gems, and instead of
replacing the false one with the real one, I must have put the false one
back, and really threw away the true Eye."

"Then--I throwed it away in Bombay."

The lama considered the statement made by Tip.

"If any of you speak falsely," he said, slowly, "you who speak so shall
hear the Voice of Doom and shall feel the Wrath of the Hand of Doom."

With that threat he bade them depart.




                               Chapter 23
                             THE ACID TEST


"Oh, no you don't," Grover spoke for the first time during the
interview, "there is a matter of a vanished scientific student of the
stars, a shot prior to his disappearance, and other things."

The lama turned toward his aides.

Grover, as Roger and Potts sidled close, smiled.

"An hour and ten minutes has elapsed since I arrived," he remarked,
pleasantly, cool and slightly triumphant, "I would not be
surprised--yes, there they are."

The police car, sent by the Chief of Police, brought two patrolmen and
as a frightened clerk ushered them in, the lama shrugged.

Captor became prisoner, and with his pair of native aides, the lama was
taken to the laboratory by the interested officers.

There, as Grover's car discharged its crowd of former captives, Roger
was able to reward the taximan who had faithfully read his signal and
who was waiting with a patrolman to be assured that all was well there
before going to the address the taximan had noted.

"I knew this joint was lucky," the taximan chuckled, pocketing a
pleasing tip, "Hope all stays well--but if it doesn't--I'll be handy."

While Tip was sent to develop camera films from various devices which
had been set off during the exciting developments, Roger was busy
assembling the ingredients for an experiment which Grover meant to
conduct, in order to learn which of the people there had held the pistol
that might have harmed old Astrovox--that had certainly been fired in
the office.

To their surprise as they brought together the necessary chemicals and
Roger got out plaster-of-Paris from his stock-room, with highly refined
paraffin, the star electrician, Ellison, arrived.

"What brings you here at five in the morning?" Grover stared at him with
a degree of suspicion.

"I have been working out theories about our queer situation," declared
the electrical specialist, "I could not sleep, because Clark had told me
all about his experiences with Roger in Tibet, and I was of the opinion
that Roger might be in danger."

"I told him how they had captured you," Clark said, as Roger recalled
that they had worked together in India on power-construction, so that
there was nothing to fix suspicion on them in thus having a reunion
after Clark's return.

"I went to your home," he told Grover. "Roger's room was open, his aunt
was greatly disturbed because you were also absent."

Naturally, he had come to the laboratory.

While he softened the paraffin, Roger told him their adventures.

"Now," Grover told the absorbed patrolmen, and a detective who had come,
by Police Chief's order, from Headquarters, "here is a dodge that some
police departments have tried, and it will interest you."

Roger assembled on the interviewing desk his heater for a great lot of
the wax, held in a crucible over the electric stove. In a large glass
container he mixed, according to a formula dictated by Grover, nitric
acid and other chemicals, which discretion suggests should not be
mentioned here.

"The purpose of this experiment," Grover said, "is to learn which hand,
if any among us, held, and discharged the weapon. That seems to be the
simplest way to narrow down investigation. Once we know our culprit, he
must reveal where Astrovox is, what happened."

The very modern experiment, the police saw, was based on the fact that
the charges used in modern pistol projectiles form, during combustion,
gases which leave marks on any hand discharging the bullet.

Grover explained his procedure.

"The gases blow back sufficiently to mark the hand," he stated. "If our
test is made within five days after such an occurrence, the test will
reveal it.

"I will be first. Roger will take the wax, properly softened, and at a
temperature around one hundred and fifteen degrees, Fahrenheit, not hot
enough to scald, will pour it over and will mould it around my hand."

Roger carried out the action as it was described.

"The paraffin, now cooling, at a point where it is hard enough to hold
its shape, is taken off."

This, also, Roger carried out carefully, securing a sort of cast with
the shape of the hand moulded inside it.

This, as Grover talked, Roger carefully placed in the chemical solution,
and they all watched in absorbed attentiveness.

"If my hand has discharged any weapon or in any other way has gotten the
peculiar gases of powder combustion on it, within the past five days,
the acid and solution will bring up the stains as bluish discolorations
on the wax."

No such spots appeared.

Although a tedious operation to carry out for the Tibetan trio, and
then, by their own insistence, for Doctor Ryder, Clark, Tip and Roger,
the results in each case held them in suspense until there was clear
exoneration of all.

"But Ellison hasn't submitted yet," said Tip, suddenly.

"Because I have handled chemicals in my work that may come out in the
reaction," Ellison frowned.

Nevertheless, though he declared that his work had brought out the
stains that showed as small blue spots and smears within his mould,
everybody felt that he ought to know what he declared he did not--where
was the star-scientist?




                               Chapter 24
                      AN IMPOSSIBLE CAMERA "SHOT"


Grilled by the detective and the policemen, Ellison stubbornly protested
his ignorance of the whereabouts of the former astrologer.

He could not establish an "alibi" further than his recent call at
Grover's home which the excited sister of the laboratory head was eager
to verify.

Roger, finally, decided that there was one sure and final word to be
said by chemistry. If, as Ellison insisted, other chemicals than actual
burning gas caused the inside of the paraffin moulds to discolor, the
special tests for the chemicals he might name would say if Ellison was
truthful or not--a sort of chemical "Lie Detector," Roger confided to
Potts as they prepared for the experiments.

To their amazement, Ellison was proved honest. The tests gave a reaction
for the very chemical he named.

The Tibetans, of course, had to be released. They were warned, and
departed.

With the experiments done, the materials removed and no gain, Tip
brought up the curious situation revealed by developing the office
camera film and others.

"Here is the picture that Roger said he had it take," Tip displayed, to
the group assembled in the screening room, one "frame" of the non-flam
film.

There were the Three, the Tibetan group, confronting Roger as his hand,
on the edge of the desk, disclosed his clever use of the "take" to leave
evidence of his capture.

"Now--study this out if you can!" Tip called out from behind the
projector.

He shifted the sprocket-turning handle to bring up the next picture.

"That's the office, what you can see through the smoke," Tip declared,
"and the smoke comes from behind the desk, and so of course the man
standing there has got his back to the lens, and all we have got to go
on is his coat and his hair."

He readjusted the "framing handle" to bring the picture into even more
exact alignment with the aperture plate of his projector, so that on the
screen every part showed.

"Now, study that! There is old Astrovox, scared looking. He is facing
the big smudge of smoke from the pistol.

"But what gets me," Tip finished, "is that the whole big puff of smoke
is still hanging in the air, and the man facing it is just hit--or else
his face is contractuated----"

"Contorted," cried Roger. "Skip big words and say your say."

"Or else his face is contorted by being awful sure he has been hit."

He focused more sharply.

"You can see him clear enough to know Astrovox didn't fire no gun. The
smoke is between him and the guy with his back to us. But--just look.
His hands rest both of 'em on the desk edge. That's how he hit against
the button in the desk edge that snapped his picture.

"Now--where is any gun?"

"He couldn't have dropped it, and have gotten his hands back onto the
desk before the smoke puff would have begun to shift," exclaimed a
policeman. "Look." He drew out his service weapon, aimed into a corner
where his bullet would show little and its mark could be wiped out with
putty and paint, and fired.

The smoke, with his own movements, revealed disturbances almost as it
left the mouth of his weapon; and before he could drop it, the smoke
shifted. More! The pistol, falling, cut a swath in the pall.

"There's no gun. And no one is hiding. The smoke is in front of that man
and between him and Astrovox," the detective agreed.

"It's impossible," Potts exclaimed, "A camera can't take a picture of a
shot and leave out the gun."

"Chemicals," prompted Grover, "could make the smudge."

"Then how about this?"

Potts had another film spliced onto the first one. He reeled it in at
regular motion picture speed, and out of the speakers came the strange
and abrupt recording of a loud, sharp, detonating sound, as near to the
discharge of a pistol as any of them had heard.

Taken away by the ventilating system, the smoke of the police shot was
out of the way, the screen was clear to all, and they saw that the
camera had recorded light from the direction of the office, an abrupt
flash. With it, the detonation.

"Kangaroos and apes dancin' on a film where none could be," Tip summed
up, baffled, "and now--a gunshot where the camera shows us there can't
be any gun."

Even Grover, usually calm, looked disconcerted, and yet a little bit
excited.

"Maybe," he declared, and turned to Roger, "but here is one more 'sound'
to add to your list. And I feel sure that out of that list, either as it
is, or when you complete it up to date, will come the hint that will
enable me to clear up everything."

Over-confidence?

Roger hoped not.




                               Chapter 25
                    SCORE ONE FOR THE MYSTERY WIZARD


Grover stood up. His eyes were bright with some inner fire as he walked
forward, turned and faced his attentive audience.

"You have overlooked a number of points shown in that picture," began
the laboratory Chief.

"In the first place, assuming that a shot had been fired, you see that
there is no inkwell on the desk and that the picture of my sister has
been knocked over or has fallen over."

"You mean, the shot was fired from another direction, and not by the man
whose back is turned." The detective spoke.

"Can you see any other explanation for the disclosed conditions?"

"The inkwell was in a pool of ink on the floor when I got here," said
Roger, excitedly, "and the picture of Auntie was on its face."

"The shot was fired from a gun behind Astrovox," said Potts.

"No," Grover corrected him, "because the smoke is closer to the other
man than to Astrovox. In fact, it is up around his side of the desk."

"But his hands----"

"He did not fire a gun," answering the policeman, Grover clarified his
deduction. "But--think! Where in that office could a man be, and not
have the camera register his presence? Granting that he could lift the
gun above his head and still keep it out of sight of the lens."

"Can't be," cried Potts.

"Can." Roger almost shouted in his interest. "He could crouch on the
side of the desk _toward_ Astrovox, and shoot at the man behind the
desk, and the puff of smoke would shoot out toward the man."

"Yes," Grover agreed, but suddenly he jumped as his nerves reacted to a
new idea.

"But--wait! A gun at that angle could not discharge a bullet to smash
the inkwell."

They stared, and then admitted his sensible reasoning.

"Back where we started," growled the detective.

"It is a 'composite' picture, perhaps," said Ellison. "You know--one
part taken at one time, another exposed elsewhere, or at another time."

"Possible, not probable," volunteered Doctor Ryder. "In
double-exposures, wouldn't the smoke be--I don't know the phrase----"

"Not in register," cried Roger. "It can't be double- or triple-exposed.
Everything is all together, the smoke over the desk, and the men
properly distinct."

"It just must be some trick picture," argued Ellison.

"Did no other camera operated by some one having entered--they all ran
for three minutes--did none have the shot recorded?" asked Grover, and
Potts displayed films.

"They all did. Some fainter."

"We can test for distance, with a sort of applause-volume machine,"
suggested Ellison.

"But, first, let us come back to Astrovox," urged Grover. "He is gone.
Why? How? Did the man at the desk take him?" He turned and scanned the
groups intently. "The fellow with his back turned has your shoulders,
Ellison."

"But not my suit."

"You could change suits."

"You certainly want to 'pin it on' me."

"We want to find Astrovox."

The electrician made a grunting sound.

"I can't help, there."

Grover, though, did not pursue the argument. He seemed buried in
meditation.

"Here is something we overlooked, too." He spoke slowly, searching for
hints in his own inner processes. "Look at the smoke. The light in that
office, according to the picture itself, was the overhead dome. Now,
with that small actinic quality, the camera with a daylight type of
film, would have recorded only in exposures amounting to at least a
second. It _would_ have been possible for the man to have fired, dropped
the gun. Possibly if he snatched it up and let it drop--no. The flash
would have been filmed! Let's work at this!

"Notice--the edge of the smoke is duller, less distinct, but the lower
part of the smudge is thick and dense, as though--the smoke had been
settling during the exposure."

"So, where does that get us?" asked Ellison.

"To this. The man at the desk is extremely clear. Astrovox is less
distinct, recognizable but still a trifle hazy. We assumed it was the
smoke. It isn't. It is the fact that when he heard the shot, Astrovox
was just outside the doorway. He ran in, too fast to be recorded in that
brief exposure that caught him just pausing. Now, that accounts for the
other camera's proving that a shot was fired.

"It was fired at the man behind the desk. Then Astrovox ran in, and he
had to be there an appreciable fraction of time to be registered. He got
in just about half-way through the exposure, and his pause imprinted his
image just before the shutter closed. Now--what would have been his
natural, subsequent procedure?"

Frightened by the past sound of the Voice of Doom, he went on, the man
had been about to leave, and was merely waiting for Potts.

"He ran in, saw the source of the shot, saw the man crouched under the
desk after his shot had hit the inkwell instead of his mark, the other
man. He turned, and ran. But the man who had crouched would know that he
had been seen, must think the old man ran for help.

"He went after Astrovox--to silence him!"

The auditors, spellbound by his train of reasoning, had literally hung
in suspense.

"The man evidently had a gun," Grover went ahead with his thought,
speaking slowly. "He took only a fraction of time to leap up and pursue.
He would not have let Astrovox get far.

"Let us search the areaways nearby," he concluded, seriously.

They scattered, the police officers and the detective organizing the
search.

It was "score one" for the Mystery Wizard.

Sound had been his deductions, as events showed.

Only in one point had he been mistaken.

The old astrologer had not been shot. His limp body, brought in from its
place within an old packing case across the street, showed that not the
muzzle had been used to make of him a target. The butt of the weapon had
left its mark.

"Adrenalin--we may bring him back!" shouted Doctor Ryder.

Potts raced for the nearest drug-store, while the police called an
ambulance.

"Let me work with him," pleaded Doctor Ryder.

But Tip did not secure the heart stimulant, so seldom, and yet
occasionally able to restore heart action after it has seemed to cease.

They took him away, and Grover, stunned at his own accurate deductions,
hopeful that he had reasoned so accurately in time, went too.

The rest hung around the telephone.

At last came word.

"He will probably live!"




                               Chapter 26
                         ROGER LISTS HIS CLUES


During Grover's absence at the hospital, the staff began to arrive.
Until the secretary should come to handle the switchboard Doctor Ryder
volunteered to be monitor on calls, being extremely anxious concerning
the condition of the assaulted star-reader, as were the rest.

Roger, as Toby Smith with a heavy suitcase arrived, turned over the few
requisitions for stock to his willing assistant.

He wanted very much to fill up the list of sounds he had begun in the
office before going to Tibet.

"Suits me fine," Toby agreed, "I got a lot more of Doctor Ryder's what
he calls compounds, that he is going to use to medicate the rats he is
going to replace."

The members of the staff, trained under the phlegmatic, scientific
methods of Grover, took very little time to discuss conditions. The
routine work of scientific research had to proceed. They made it do so.
Each took up his task. Mr. Zendt, with his new investigations, and the
electricians and other staff men, left the matter that had no bearing on
their results in the hands of those most interested.

Potts, while Roger located his "sound" list, speculated about the
situation.

"That Ellison come out on top in the chemistry retroactivities," he
began, and when Roger had substituted "reactions," he proceeded:

"But are you so sure, Rog'?"

"Well, the way Grover works, I am not sure and I am not un-sure. I'm
going to dig to the heart of truth. Now, with our clues, we have a lot
of circumstantial evidence-clues; and we have a heap of visible clues;
but I think the audible ones will tell most, just as Grover does."

"Circumstantial evidence? Such as what?"

"People being at certain places. Here, maybe, when something happened.
And like Mister Ellison arriving just when we least expected."

"Then, what about visible ones?"

"The animals on a film taken in a room with no animals in it. The
actions of people, if we could only read them. The picture in the
office, last night, with a man's back turned, Astrovox scared, and the
smoke."

"The others--the vocational clues----"

"Do you mean 'vocal'?"

"Uh-hum. Them I know most of. But there's ol--olle--something about a
factory----"

"Olfactory? Clues coming from smells? I think you've got something. The
powder smell, for one."

"And now, how will we coagulate 'em?"

He was fond of that word, erroneously used, before--but to him a
discovery.

"I don't know," Roger admitted, "there must be some link."

He suggested that inasmuch as the man in the office shot had worn
gloves, as revealed on his outspread hands, no finger prints had been
left when he had inadvertently pressed the desk button.

"But there might be clues on the floor, if they haven't been tracked up
too much," Roger suggested. "You do some micro-photography while I
revise my list."

The list he located in their office file, behind the registrations he
had previously looked up to find the clue, as it had seemed, that Zendt,
with Australian experiences, must know about kangaroos, while
Ellison--there he cropped up again! could know, from India work, about
the ape they had seen in the film of the upper room.

Looking over his list, in the light of what had happened, Roger was
inclined to drop out the seemingly unimportant fact that the case had
begun when both the fire and the protective system alarms had rung. He
felt that it had no discernible connection with his mystery, being so
easily accounted for by the fact that an ape and a kangaroo had
evidently gamboled around in the studio, setting off alarms unwittingly.

Still, half-hesitant, he left it in, but re-wrote his list, so as to put
what seemed important in order, rather than try to follow the succession
of historical order, as he had done before.

His list, thus revised and added to, ran this way:

         _Sound_                         _Possible Meaning_

 1. Frying-grease-like     Claws of animal. Radiator valve with steam
   clicks and hisses and     coming in. A snake, with its scales
   pops.                     rattling. A lizard, like the big Iguanas.
 2. Voice of Doom.         Tibetans' trick to frighten. A recording made
                             in Tibet.
 3. Voice of Doom again.   On a record supposed to be new. Query: how
                             did Tibetans know all about our stock to
                             substitute? Query, could Ellison have done
                             it?
 4. Doctor Ryder's talk    Voice was his. We thought and he admitted it
   with man on record        was Mr. Clark he was talking with. Query,
   with No. 3.               we thought it was to conceal identity that
                             Mr. Clark wrote; wonder if it was not a
                             talk with him in room, if he telephoned
                             instead? Is Mr. Clark completely cleared:
                             he is a jeweler.
 5. Clicks in headset.     Could be so many electrical switch noises or
                             relays, but why was it so close to hearing
                             Voice of Doom?
 6. Drip or click in       Was just before safe was opened, but was it
   dark.                     the combination being worked by expert who
                             could tell by sound when tumblers fell
                             right? Does that make me think of Clark, a
                             jeweler? Not Tibetans as we had thought
                             from circumstances. Is Ellison able to work
                             a combination "by ear"?
 7. Thump or thud sound.   Seemed to come in corner of room upstairs
                             just before I took the film that produced
                             the animal 'ghosts' after we had heard
                             Voice of Doom from up there. I wonder how
                             important it really is, or if it was just
                             plaster or a film in a can?
 8. A sort of thump on     We thought he had been knocked down by a blow
   Record when Dr. Ryder     with recorder operating. But it turned out
   vanished.                 he had gone away with Clark. Or so Clark
                             said. Has Clark got some hold over Doctor
                             Ryder that made him go after a telephone
                             summons? Was that thump the telephone taken
                             off hook? Not likely as it would be a click
                             like what I heard in headset. Do these tell
                             me anything?
 9. The cry of fire and    No fire, and no reason for cry. Wait! It was
   crackle of flame on       like what old Astrovox said when we were
   unused record in my       collecting old papers in upper room? Is it
   room.                     possible anybody made a record of it? But
                             Potts was the only one who was fixing
                             protection machines in my room. Yes, and
                             Potts says he threw away what turns out to
                             be the real Eye of Om. Oh, it can't be.
 10. Both alarms went      Can't mean anything but I feel like keeping
   off when mystery          it on record.
   began.
 11. Shot recorded in      A brain-teaser. It was an explosive sound,
   the lab films at same     that synchronized with flash in film: and
   time as flash.            there was the smell of burned powder. How
                             does it fit? Did Clark or Ellison do it to
                             try to shoot the man at the desk? Or did
                             either one do it at the other?
 12. The Tibetan talked    It _is_ 'sound' and might have some clue, he
   English.                  used English in a Tibet monastery, and in
                             America again.
 13. The whistle and       Wind howling as it blew hard or gentle in
   moan in Tibet same as     tunnel and Buddha-whistle. But no 'grind'
   on recordings.            in Tibet.
 14. Grind as if rocks     Missing in real Tibet sound, as rock was
   on records, after         counter-weighted and moved silently open
   Voice of Doom.            and shut. Seems important, because it was
                             on record probably made in Tibet and
                             brought here by--Tibet lama? Clark?
                             Ellison? Zendt?
 15. Voice of Doom heard   Was it record, same as others? Or what? I
   by Astrovox.              must ask when he recovers if it had grind
                             at end of moan.

Those, as far as he could recall, were his sound-clues.




                               Chapter 27
                           A "THERMAL" TRICK


With every meaning that he tried to attach to his listings, Roger found
himself growing more confused.

He had only imaginative evidence against any of the names he had
inserted in his diary-like notations. As he scanned his list Roger saw
that he had done less interpreting than speculating; but he saw no way
to make interpretation of the listings get him anywhere.

He filed it with his former list, and went to his routine, so that Toby
could go to dinner.

The rest of the day was without apparent development.

Toby, leaving the suitcase, at closing time, went home. The others did
the same. Roger and Tip remained until last.

"Well, Grover has stayed close to Doctor Ryder's patient," Tip mused,
aloud. "That is, the patient Doctor Ryder just missed getting, because I
told the druggists I wanted 'aggrenalin' and they said they never heard
of nothing like it. If I'd of got the right name, he'd of saved Astrovox
'stead of the internes doing it."

"I talked over the wire with my cousin," responded Roger. "Just make an
extra check on everything for safety's sake, and he says for us to _stay
away_ from here, tonight, no matter what we hear. You are to go to a
hotel to sleep. And he says you must."

"What's going to happen here?"

"I wish I guessed," Roger retorted, "but I don't seem able to do even
that. With all the clues on my list or somewhere in the films and so on,
I just see new developments, and they are worse than before, and confuse
me."

"What say we go to one of those spirit mediators."

"A medium? A fortune teller?"

"She might coagulate our ideas."

"Curdle them? She probably would."

"It means to make 'em set--hang together."

Roger chuckled and refused. He wanted to work out every circuit, trace
every wire, be certain that when he locked up, nothing could get in or
out of that research laboratory without leaving a record and if anything
happened then--well--he'd have to look to Tip about it!

Potts said good-night, and went away as instructed.

At home, telling with some reserves his experiences of the night before,
to his aunt, Roger felt a constant tugging of desire to go and see if
all was right.

Grover's orders to stay away were, he felt, a magnet drawing, tugging,
pulling him toward the forbidden place.

What danger, he wondered, might lurk in just a visit?

Still, he obeyed, against every dragging urge.

Toby Smith telephoned about nine o'clock.

"Say, can we get into that lab?"

"Why, Toby?"

"I clean forgot to put away Doctor Ryder's compounds. I put down his
suitcase, and got busy with Mr. Zendt who wanted a heap of chemicals,
and it slipped my mind."

"Orders are not to go there at night," Roger told him.

"Well--but he said lock 'em in the safety cabinet, against fire. I
forgot. Well----"

"But there won't be any fire."

"But--lookit, Roger--you didn't notice, maybe----"

"That you had marked on a paper a list of words? I did. Fireworks.
Pyrotechnics. Lycopodium."

"Well--I mixed some--an' left 'em in a big tray till tomorrow."

Roger gasped, at his end of the connection.

Suppose a gas in the atmosphere reacted with some exposed ingredient?

All at once, though, a person so far totally unsuspected began to assume
importance.

This Toby Smith! He had originally sold, for a camera, a gem supposed to
have been both sacred and invaluable.

He had been to Tibet before, Doctor Ryder had mentioned. (He could have
known the value of that gem).

Besides, here he was, at a time when Grover had explicitly forbidden
Roger, for some hidden reason, against going near the lab. And he was
insisting on his disobedience of orders by implying dire happenings!

Roger hesitated.

Why was it important for him to be lured to the laboratory? Had Clark
not explained to the Tibetans about the blunder through which the real
jewel, jettisoned by Clark, picked up by Potts, had been lost, they
might want to lure him, to bring some idea of revenge to pass.

Why should Toby want to do that?

Perhaps, Roger speculated, the youth wanted to get him there and then by
use of force open the safe or some other thing.

The value of their own laboratory formulae and data was not less, to
them, than a jewel such as the Eye of Aum.

"Against orders!"

Roger, his decision made, started to hang up.

"You'd let that stuff explode, maybe----"

"Listen, Toby. I obey the Boss. Besides, don't worry. We have a
positive-action, fire smothering gas in drums, and a thermostat that
operates a relay, much like those on heating equipment, at a rise of
eight degrees from the normal shown by another thermometer outside the
lab. The gas smothers any fire. Chemicals, even."

"That's good. Then I needn't worry."

"You needn't worry, Toby."

Hanging up, Roger waited for a further effort.

When it came--if it _was_ a new attempt!--its form was startling.

The inter-connecting fire alarm in the library of his home rang. Roger
considered for a moment. Of course, the gas should cover every possible
danger, save everything. Even against the delicate electric adjustments
and the unreplaceable devices, the gas would work without harming them
as water might do.

The thought brought another.

"Water!"

The firemen would respond to the alarm, sent out over the telephone, to
Headquarters, automatically.

Water would ruin the delicate armatures, coils, etc.

And how could the alarm go off by human means when he had made so
certain that no one could enter?

He decided to try to get Grover at the hospital where he waited for any
word, or murmur, raving or otherwise, from the unconscious astrologer.

Grover was not available, they told him. He had gone out to get a late
repast.

Grover would not be available for an hour. Roger could not see the
laboratory electrical apparatus ruined. The order to stay away had not
taken this development into account.

He got a taxi and was hurried to the vicinity of the lab.

Already he heard the screech of sirens, as at the start of the queer
chain of contradictions, impossibilities and misfits.

This time, though, a weird orange-reddish glow came up into the cloudy
sky from above their skylight!

As Roger leaped out, flinging the taximan a dollar, the glow was quashed
as if by magic. The system of protection had worked.

He stopped the breaking of the door, as before, but this time with no
need for argument. The X-Ray and fluoroscope were not going as they had
been that former time.

Hastily Roger located the Captain of the first company to have arrived:
he knew that the one so scoring a beat was in charge, stayed till last,
was responsible. It was "his fire."

Rapidly he told as much as was necessary to convince the man that no
further damage could possibly ensue, but he found the man hard to
convince.

"But I declare," Roger insisted, "the lycopodium and stuff that you saw
blazing up through the skylight was just fireworks compounds, made up--I
begin to think--for just that use. It made a grand glow, but probably
blazed only in a tray. The room it was in is fireproof. Our film is all
non-flam, in sealed or airtight cans. Our chemicals are in airtight
containers."

He added that his check of the tell-tale, on the brief entry he had
made, disclosed no entrances by others. Such was impossible.

"Then how was the stuff ignited? Spontaneous combustion."

"I suppose some gas was left open, on purpose, that would in time
penetrate to the chemicals in the mixture. But the heat of that little
couple of pounds of powder burning ten minutes would not raise our
fire-thermostat more than a degree, and it must go up six or eight to
set off the alarm."

"The alarm came in, young fellow. How?"

Roger took him across to a drug store. In its window, against the wall,
a huge advertising thermometer registered Fahrenheit degrees and stood
at sixty-four. He hurried the man back, showed him the small
interconnected thermometer for registering air temperature, against
which the other inside one reacted. This one stood at fifty-five.

"Somebody wanted the alarm set off to lure me here--simple trick. Only
had to hold ice on this one till it dropped eight degrees _below_ the
other and then the other would be eight above it and off went the
alarm."

Fire, an alarm adjusted for heat, set off by ice! Toby? Who else?




                               Chapter 28
                                THE FUSE


From the pay station in the drug store Roger got the hospital and was
connected with Grover.

"Is Astrovox all right? Did he say anything?"

"He will probably recover, Roger, but he won't talk for many days,
perhaps for weeks."

Rapidly, concisely, Roger outlined the situation.

"But I told you----"

"I am not in the lab. I went right away from there, making sure all the
safety things were still on, before the firemen had pulled away."

"Don't go back, no matter what. And--Roger--be sure your room is
protected fully before you go to bed."

"What's the matter? Do you know?--who is it?"

"I don't know who it is, but some desperate person has determined to
protect him or herself by any necessary means."

"The Tibetans?"

"I think not, Roger."

It was some person or group recognized by Astrovox. That recognition had
led to the blow he was suffering from.

"Fortunately, it was not fatal," Grover continued, "and I stayed here
less to hear him, for I knew that would not be probable. I was here to
protect him if anyone, knowing he lived, tried more desperate methods
still."

"You can't stay day and night."

"No," answered Grover. "Potts is on his way here now. I will be home in
an hour or a little more than an hour."

Roger asked one more question.

"Why would they want to lure me to the lab?"

"No other way to get in."

"But they did get in, Grover. The lyco----"

"Probably touched off with a long pole, from the skylight. They could
break the glass, insert a long pole, like the one we use to shift the
ventilators. To draw firemen who would smash in--or set off an alarm
that would bring you, especially after the preparation by Toby."

"Then he----"

"Probably someone either paid him well, or else, as I think is more
likely, he really had left the powder there. Some one knew it."

"Why should I be bothered?"

Grover's theory was that through his reputation as the Ear Detective, or
else because of some film or other data, the suspected miscreant feared
him as he had feared Astrovox.

The conversation ended and Roger, finding his old friend, the taxi
driver, on his night station, used his car.

At home he made certain that the devices, moved from Doctor Ryder's
residence, which no longer seemed threatened, because the absence of the
Eye of Om had been explained to the Tibetans, all worked. He shifted the
recording needle a dozen turns of the threaded arm that made it follow a
spiral path. The call of "fire" and the crackling noises occupied only
the start of the disk. He set the recorder to fall in place further over
toward the center.

Switching on the electrically charged locks, he kept his desk lamp
burning while he retired.

Just as he was about to turn it out, the light died.

Thinking that the bulb had been used up, he tried another light, just as
a precaution, recalled to mind by the doctor's experience.

That light was unresponsive.

At once Roger raced to the door into the hall.

With no current the lock, with his key inside, turned readily.

Intuition told him what had happened here, as in the other instance.

The cellar fuse box had been opened and a fuse had been removed. That
prevented current from entering the circuits, and even the alarm was
silent, although he knew that cutting off the current served as well as
any other way to start the recorder disk and the camera. He cut them off
hurriedly.

"I'll want them, maybe, a little later," he told himself. "Whoever did
this will have to come up two flights of stairs. It will give me just
time to re-adjust them to go on again, if I want. And I hope he or she
or it left the fuse by the box."

He had a plan. A trap, made useless to protect him, could be made useful
to hold someone else!

Slipping into his bathroom, with his clothes carefully tucked under his
arm, Roger unlocked the door into Grover's adjoining room.

He went in there stealthily.

Then, waiting, he listened.

His one danger lay in the chance that the miscreant might come by way of
Grover's room, if it was known to be empty.

As he heard someone working a jimmy or other springing implement on his
door, very quietly, though, he slipped into the hall with as little
noise as the hinges of the door allowed. It was hardly likely that the
slight squeaks were audible down the hall.

He saw a man, bent low, his back fortunately turned that way, as he
tried to snap open the lock without much noise, perhaps trusting that
Roger slept soundly and would not awaken.

Like a wraith slipping without sound along a haunted hallway, Roger got
to the stairway. Its noise must be risked. He trod close to the wall
side, stepping two lifts down to avoid a known faulty stair.

It required nice psychological deduction to enable him to use his trap,
if the fuse was available. The marauder, or worse, must be in the room,
and as Roger hoped, he would probably have shut the door to muffle any
commotion from getting to other possibly occupied rooms.

Once in, the person would see he was not in bed, and had not been, and
would either take a moment to discover if he hid, or would pause to
consider; he must have been watching, must have seen Roger arrive.

The fuse, when he snapped on a cellar bulb in the garage, was on a ledge
under the switch box. Was it too soon, Roger wondered, to screw it into
the tiny receptacle?

He must not wait too long. His absence once assured, suspicion and fear
would drive out the one who was now _his_ quarry.

He must risk it at once.

He screwed home the small 15-ampere fuse.

With hopeful heart and padding feet he ran up the cellar steps, up the
next flight, and paused to take observations.

All was quiet.

Had his trap sprung? He could tell by finding a rubber glove among
Grover's things, with which to try the knob he had so recently turned
with ease into his bathroom.

He got the insulating glove from among some old laboratory togs, too big
for him but satisfactory for his need.

With care he turned the knob. The door did not yield. The system was on.

A difficulty came into mind.

To see if he had a captive he must release the heavy charge, by use of a
small cable-key that broke the circuit. If his presumable evil-wisher
was caught, he might get out before Roger could re-set the system.

He listened. There was not an audible sound, coming through the door.




                               Chapter 29
                          A SURPRISING CAPTURE


A sound in the lower hall made Roger turn. To his delight, Grover came
in. Quickly the younger cousin set out the situation.

"Go down and draw the fuse again," Grover suggested. "Queer that I did
not think of that simple way to nullify all our protection. It explains
how the safe was so easily opened, as well as Doctor Ryder's situation.
When you are ready, pull only the ten ampere fuse in the equalizer of
the circuit marked number four."

Roger knew that the switch and fuse box held different fuses for various
parts of the home, with two heavier fuses set into the main feed from
the street. Grover's idea was, he saw, to eliminate the front portion of
the house including his room, while the light in the rear of the hall,
and his aunt's quarters, would be left on. In that way, with a front
hall light going, Grover could tell when the fuse was out and have light
enough in the hall to work by.

As soon as he had performed his task he ran up the steps, to find
Grover, extremely surprised, facing, in the hall, the last man they had
suspected of interest in the matter.

The assistant electrical engineer, Mr. Millman, stood there.

"A lame explanation," Grover was saying as Roger arrived.

"To you, maybe. To me it seems reasonable that I would have hit on the
method somebody used to get to the safe and I think it is perfectly
logical that I should test out my theory that Roger had been playing all
those tricks in the laboratory."

"What tricks?" Roger demanded.

"This one, if you want a sample."

Millman walked over to the recording device, exchanged from his pocket a
reproducer, made a quick wire connection to Roger's compact table radio,
as Roger had had the connection when the recorder had roughly re-played
the formerly recorded cry and crackles.

"I was making a recording of motor sparking, and just as I set our lab.
machine going, I realized that the diamond was cutting a sound record,
not just running smoothly. You can tell if you are watching closely, as
I was. We cut out the record, took it off, and I told Ellison and Zendt
to say nothing. I began to suspect that Roger, who was up with Astrovox,
was having fun at our expense."

He set the machine going and the needle, automatically dropping onto the
groove just beyond the cuttings, as Roger had set it, had to be lifted
back. Then Grover heard, as had Roger before, the cry, "Fire" and the
rattling, crackling as if flames ate dry wood or paper.

"Now if that was recorded, it had to come from somewhere. We had not
started the sparking motor." Millman was earnest. "And I knew that Roger
was up there. Later, unable to find this record, at the laboratory, I
reasoned that it must be that Roger had brought it to his home.
Evidently, I thought, he wanted to hide it. I decided to make sure.
Being an electrician, I thought, at once, how to get in by pulling a
fuse, not needing to cut wires or put the safety devices out of
commission permanently."

"What do you think, Roger?" Grover turned to his younger cousin, "Does
it strike you as convincing?"

"Maybe he might feel that way."

"But--with some desperate person abroad----"

"Do I look desperate?" Millman laughed. He was tallish, and a most
serious mannered, quiet, earnest person. "What motive could _I_ have for
wanting to hurt Roger?"

"You can best answer that," Grover said quietly.

"I simply wanted to justify my belief that Roger was behind all the
spooky goings-on; the animals on the films, and so on." He nodded to
show his satisfaction. "I think I have proved it."

"Did Potts put this record here?" demanded Grover, and Roger saw that he
was thinking fast.

Hating to add still one more count against the handy man who had only
his own word to support his declaration that he had flung away a
supposably priceless Eye of Om when Clark had made his blunder in the
temple, and Potts had found the discarded gem, Roger nodded.

"And how was the recording made? Do you know?"

Again Roger nodded. Grover frowned.

"How?"

"I was helping Astrovox carry away packing papers; and he mentioned that
Mars, the planet, ruled fire. That word, and the crackle of the paper
bunched up in our arms, would make that sound."

"Was there an open microphone near you?"

Then Roger started.

"No."

"Then--how?----"

"If we could go to the lab." Roger had an inspiration, "I could show
you."

It would keep till morning, Grover decided; and dismissing Millman with
a warning that his actions were at least not beyond suspicion, Grover
set the cable-switch on, and prepared to sleep with Roger.

During the balance of the night their rest was undisturbed.

As soon as they reached the laboratory, Roger took Grover to the
recording machine.

"You will think I did this, because I know so much about it," the
youthful radio and sound expert said, "but it is just putting a meaning
behind certain sounds on my list, and adding the natural explanation."

His reasoning proved to have been correct.

A strange voice had come unexplainably from an upper room having no
occupant:

Roger bent, examining the mechanism under the recording turntable. He
investigated the contacts whereby the electrical impulses sent from the
small "mike" at the sparking motor, through the selenium cell, got into
the amplifying transformer-coil to be increased enough to operate the
recording diamond attaching to a special diaphragm over the disk on the
turntable.

"A wire had been soldered on, here--see," he pointed. "Somebody had a
wire that didn't need to be there. Now, if I just wind this end of a bit
of wire around that contact, to replace the missing one--" he made the
temporary connection, "and lead it down to one or the other side of the
floor outlet, and there attach it even loosely around one prong of the
little plug-in that furnishes current for the motor of our recorder, we
may discover where the speaker upstairs is located."

Hastily he made a temporary splice onto the plug prong. Grover went up
the steps, pausing as Roger put a commercial test-record in place,
switched on the motor and set the reproducing needle on the groove.

Immediately, from upstairs, there came the recording, in a booming,
hollow distortion, natural to the poor connection and the device they
had to locate above.

Grover, walking over to the corner from which came the sound, gave a
surprised call for his cousin who shut off the record and ran to the
disclosure he was sure he would find. His guess was right. There, laid
practically flat on one of the empty cabinet shelves, with its small
speaker-unit set into a cutout spot of the shelves, and concealed by the
thick wood it was let into, was a good sized slab of thin wood.

The wires to the small operating battery concealed in a non-flam film
can, and from that running to a wall outlet that connected the room
devices with the main source of current, they traced.

A recording had been made, downstairs, of voices in the upper room.

To all appearances there was no microphone up there to have conveyed the
voice and paper-rattle. Apparently there was no loud speaker up there to
have broadcast the Voice of Doom so bafflingly.

"You say to dig past appearances," Roger reminded his cousin, "and while
they can be falsified, the truth never changes. Well, if it 'appears'
that there is no mike, and that there is no speaker, we know we heard
the Voice of Doom, and we know we heard the recording made by Astrovox,
upstairs, on a record, downstairs."

"There is, naturally, some connecting wire. But--it does not show. You
know more about radio than I, Roger. Have you located it?"

"Well, when we used to build experimental sets, before commercial radios
got to be common and reasonable in price, I used to try to record my own
voice, so I could play it back. I used the same sort of radio hookup for
that, I think, that is used in making commercial phonograph
records--only, I didn't have a carbon mike, so I tried reversing the
function of the speaker I had. It was a Balsa-wood one, that I assembled
from a small vibrator-unit, and a flat slab of thin Balsa-wood."

"Used the speaker as a microphone or telephone receiver would be used
today."

"Right, Grover. And, another thing I remember from my experiments. There
was a device that was supposed to use the house electric wiring as an
antenna--an aerial. If you put a special plug, with only _one_ prong
instead of two the way regular electric contacts are made, in a wall
outlet, the circuit of the house current was not carried at all, and the
single contact went to the aerial binding-post of my set, and made the
whole house wiring act like an antenna. There was a terrible line-hum.
It wasn't practical. But I think----"

"As long as only one 'side' of the house current is tapped," Roger told
his cousin and Chief, "and the part it connects with is not grounded, it
will act like an antenna--or, in this hookup, it makes any of our
outlets a conductor between whatever is plugged into it and the
Balsa-wood speaker."

"Besides Ellison and Millman, both electricians," Grover mused out loud,
"Potts would know, at least from observation, a lot of electrical
'stunts'. This one, possibly. And he knows how to record; and all about
microphones, speakers and other apparatus that he has to adjust in his
regular laboratory duties."

Another count against Potts, Roger thought--at least by implication in
the evidence.

But, then again, it also pointed to Ellison or Millman, maybe both.

Toby arrived. As with Roger he viewed the cremated powders, and the
melted metal tray on a scorched table of fireproofed wood under a zinc
sheathing, where his "pyrotechnics" had burned, Roger had to admit to
himself that the youth's manner and expression indicated sincere shame
that he had experimented and had left his combustibles exposed. But,
then, the call had come, last night, so close ahead of the fire alarm
that had led to his trip to the lab. Had Toby been lurking nearby after
having chilled the outside thermometer enough to cause the one on the
alarm system to be higher and to set off the device? There had not been
enough heat to release the gas, he made certain of that at once. Toby
_might_ be one of those "dumb"-clever fellows who pretended to be
ignorant to cover up something, to keep suspicion away from themselves.
He decided to add Toby to his list of potentially suspectable people.




                               Chapter 30
                         THE VOICELESS WARNING


Since Astrovox would be away for a good while and his experiments could
hardly be picked up by anyone else, Roger was told to arrange a
temporary home for the rabbits, squirrels and mice and rats he had been
experimenting on; and a nearby pet shop agreed to house them.

In assembling their cages, Roger noticed several of the mice showing
symptoms of being very nearly done for.

"What do you suppose is wrong?" he asked Doctor Ryder, who was clearing
aside some of the absent man's apparatus in order to set up his cages
again. He expected a fresh litter of white rats for his medical
experiments.

"There was a fire, wasn't there?"

"You think the smoke overcame them, Doctor?"

"Exactly, Roger." He wrote down some stimulating combinations of
medicinal chemicals to try on them.

The bio-chemist, Zendt, also took an interest.

"Of course, if the lamps are already turned off," he said, "it is that
the smoke overcame them. That little fellow is particularly bad."

He indicated a tiny mouse of the sort used in the experiments, lying
almost as if in a coma.

Roger, with his quick sympathy, and with Toby eagerly obeying orders,
improvised a makeshift "oxygen tent" and since it would be in the way in
the room already crowded with the cages and plant-beds, he took the
small stimulator with its tiny occupant into the dark-room where he
could attend to it and watch the mouse's reaction and response while he
developed some plates taken by the staff the afternoon before.

The mouse, Roger saw with pleasure, gave signs of reviving.

So quickly it recuperated that he put it back into a cage, but kept it
near him in the dark-room while he saw, on the developing plates, slow
images emerge.

The pictures, photographs of crystal formations, he finished, making
wet-contact prints. These he took to Mr. Zendt. Others, of the old
astrologer's, he put aside to print later. They would not be needed for
some time.

Coming back, Roger observed that his tiny patient was apparently much
better. He dissembled the oxygen apparatus, and was about to take it to
his stock-room, to the section where spare apparatus was stored, when he
had a visitor.

Mr. Clark, his Tibetan traveling companion, the well-to-do jeweler, came
in through the light-trap, with a cheerful greeting.

"How are you doing?" he inquired, "and what is the latest quotation on
Tibetan's, common." His stock-market joke made Roger grin.

"Glad you didn't say 'Tibetan's, preferred.'" he answered. "As far as I
know, they certainly are not preferred. The quotation is
lower-than-minus. No sale."

He was wondering what might be the object of the call.

Not a visit for love he was sure.

"I hear there was almost a tragedy here," the rich gem expert was
getting to the point, Roger surmised.

"Yes, sir."

He was not going to give information.

"Poor old star-gazer. He should have seen his fate coming. If his
star-reading could warn him, why didn't he take care?"

"I don't know. He had said something about Neptune and Saturn in
opposition and Mars opposed to Uranus, with the world between the
opposite planets, pulled this way and that, if I understand him. Maybe
he was trying to take care of himself, but he always says we are put
into this world to have certain experiences. We cannot escape them, and
what the stars' forces did to influence our cells in brain and body at
birth, he thinks, indicates what sort of experiences we will have."

Roger, seldom over-talkative, was willing to expand this idea.

Not that he wholly grasped what it meant. Nor was he "sold" on the star
philosophy. But it diverted Mr. Clark from whatever plan he had come
there to try, Roger thought; and if he was right about it, Clark would
come back to his subject and would thus show Roger what it was.

"Astrovox often said," he hurried on with the topic, "we cannot avoid
our Destiny, escape experiences. But we have what he called Free Will to
decide how we will meet them."

"A very sound philosophy, Roger. But----"

"Now he's going to give himself away," decided Roger.

"But--where have you put The Eye of Om?"

Roger, petrified by amazement, could only stare, in the dim, ruby
dark-room light. "I?----"

"Yes. Eye of Om. You really took it, of course."

"Mr. Clark!" Roger drew himself to his full height in sudden anger at
the challenge, the accusation.

"Well, how else could it have happened? You know, for you saw, when the
prongs in the Buddha's forehead socket were loosened, I took out the old
gem and put in a new one--the one we had brought. And when you sent
Potts back, do you imagine I am idiot enough to believe that _he_ knew
one stone from another, or that he found the one I chucked away into a
regular abyss, there in the Himalayas?"

He scowled.

"You went there. You saw the real stone put in. You sent Potts to--shall
I say the real word? No--to bring it--that's close and not quite so
evil-sounding as the fact. Anyway, Roger, do you think we don't how
loyal Potts is to you? He would tell any sort of story, just to protect
you."

"Say, you go and tell Grover that."

Roger was boiling.

Clark, scanning his working face, calmly chuckled.

"Your films will be overdone, or whatever happens if you forget them."

Roger, reminded, hastily extracted from trays the plates of an
experiment with chemical diffusion, and got them into hypo.

"I shan't bother Grover. We discussed it and he suggested coming to you.
As long as this way doesn't elicit the information, perhaps there will
be other methods. You know what taking the gem means to those Tibetans?"

Roger, fuming, smarting under the unjust accusation, refused to reply.

Turning on his heel, Mr. Clark left.

Roger washed his negatives, made his prints.

To his surprise his pet, the tiny mouse, began to run about, to show
unmistakable signs of animation--or was it of excitement?

Roger studied him.

The tiny animal was racing around its cage.

Memory of the fact that such mice on submarines indicated the presence
of leaks from battery or engine of undetected gases such as sulphuric
acid gas came. He wondered if his dark-room held such a menace to
respiration. He decided to take the mouse to the outer air and observe
its reaction.

To his dismay, the inner door of the light trap did not respond.

He was wedged or otherwise fastened in. And the mouse was certainly
exhibiting signs of uneasiness.




                               Chapter 31
                           THE HIDDEN MENACE


Instead of shouting, beating on the door and otherwise wasting energy
and using up the available oxygen of the room, Roger paused, taking only
the precaution of mounting on a high developing table, to avoid any
floor accumulation of poisonous fumes.

Such mice, he remembered, could detect a dangerous fume long before
human nostrils caught the odor; and this made them life-savers on
submarines. They gave the crews time to trace gas fumes and suppress or
nullify their effect.

"Now, there isn't any gas I know of in what I am using," Roger spoke,
under his breath, to his tiny companion, just as most people will
discuss an emergency with a dog or cat.

Fumes of such chemicals as he might use for "reducing" and
"intensifying" improperly exposed negatives gave off offensive odors in
certain mixtures; but he had mixed none. Hypo was not dangerous: and the
ventilating system should have sucked away any fumes of whatever sort,
he knew.

Nevertheless, the animal grew still more excited.

Roger lighted the white, glaring dome light, ignoring possible ruining
of the developing plates in his trays.

He knew every content of that room.

Nothing was out of place except what he had been using.

There was the extra paraphernalia of the oxygen apparatus. Nothing else
was visible.

It came to him that no odor or fume could be liberated that would cause
such frenzy in the little white savior unless it was introduced from an
outside source.

He would find out.

He went to the intake of the ventilator, and with litmus paper, and
other handy agents, he made several tests, keeping his nose and lips
within the tight folds of a handkerchief as he did it.

The litmus did not at once indicate anything. But when he thought of
what he had sometimes read of closed garages, with car engines running,
in which people had been overcome by exhaust fumes such as carbon
monoxide, he made a hasty test, with what he had available, and was very
sure that the gas or one of that nature, was in the air.

A tiny animal might be going to save his life. Roger knew his next move.
He would shut the ventilator, prevent the inflow of any more fumes,
leaving the exhaust openings to suck clear the accumulation which would
lie near the floor. He got his oxygen equipment, and climbing onto the
highest table, he made an improvised airman's outfit such as they used
when ascending beyond the human range of breathable air. He used his
oxygen and mixed it with air inhaled only through a handkerchief
strainer.

He thought in this way he could hold out, and then whoever had come so
close to being in line for the electric chair----. He watched the mouse
for signs.

After a few minutes the animal, at his level, quieted.

Roger, allowing still more time, finally laid aside his protective "gas
mask" arrangement, and quietly tried the door. It had been unwedged. He
did not emerge, however, but went into a corner to wait.

Whoever might open that door, he thought----

A criminal would haunt the scene, to see the effect of his plan.

Would it, he wondered, be Clark? He had threatened. Or--Toby? Or
Millman? Of course not the Tibetans. They were not chemists: they were
priests.

He grew tense, watchful.

The outer light-trap door was being opened.




                               Chapter 32
                          SCIENCE FIGHTS CRAFT


Watching, Roger saw and recognized the man who entered. The bio-chemist,
Zendt, came in with a film magazine of exposed celluloid in one hand.

"How are my diffusion shots coming along?"

"In the hypo."

Roger watched narrowly.

Zendt was either a master of facial control or he was one of those
"innocent bystanders" who manage to intrude when some crucial point of a
drama is about to be played.

"Please develop this run from the speed camera. Ellison and Millman have
caught the torque of their erratic motor on film. Sixteen exposures to a
foot--a million to the minute. Shooting time, one half minute. Does that
tell you the size of reel to wind it on?"

Roger, making mental computation with one side of his mind as he studied
the situation with the other, nodded.

He would put the ceiling light out, but he would not satisfy Zendt by
staying there. Perhaps the man came prepared to hold him at his
dark-room work in case he had not yet been sufficiently dosed.

"Bring you prints soon," he told Zendt. "I'll get this into a developing
tank." He risked a question.

"Is anybody in the cellar? The ventilator seems to be choked. No air
comes in. It's--stuffy."

"Maybe. Millman was down, earlier. Potts hasn't come. Grover has gone
out." To let Potts get sleep, to stand guard over Astrovox, Roger
decided.

"I'll telephone down and see--oh, look. It was shut off."

Clever actor or innocent intruder, Zendt betrayed neither interest nor
disappointment. He simply nodded and went out.

Roger considered his position.

He reasoned: if Zendt was blameless, some one else was watching. From
seeing Zendt emerge the unknown would be sure that Roger was still all
right. But if he left, all possibility of detecting who was the culprit
might be gone.

Still, he had no chemicals in assortments that would enable him to
detect the possible introduction of some fume through a hole in the
walls, or some other move. Besides, he was open to bodily attack.

He must not be there. No one must see him leave.

He remembered that there were chemicals that he would need, and inasmuch
as he was known to be all right, he could easily get them.

He emerged, seeing Doctor Ryder busy with his arrival of white rats,
with Toby helping him put them into the glass pen through the trapdoor
in the top that prevented them from escaping.

"Got to force-up some underexposed negatives," he remarked as he passed
them. To the stock-room he went, and procured the ingredients he needed;
but not for an intensifier for under-exposed film! Returning, he noticed
Zendt, watching the rats also.

Once more in the dark-room Roger proceeded methodically and carefully to
produce a very businesslike detonating torpedo with crystals of gritty
hard iron oxide-rust! to take the place of the gravel usually packed in
a commercial torpedo of the sort formerly sold for exploding by contact
with the sidewalk.

The other ingredients he mixed with care as to method, as well as
formula, knowing that certain chemicals must be combined in a certain
sequence. Wrapped in a fairly good paper taken from a packet of printing
paper, he had his torpedo ready at last.

There was no window from which to fling it, but he knew that by putting
a chair on the developing table by the wall, he could get his hands up
to the small outlet around the exhaust fan. The old equipment,
discontinued since the laboratory had put in air-conditioning, led to
the open air.

He got to the position carefully, took his torpedo, and adjusting the
small exhaust fan so that its blades would interfere the least with an
open passage for the missile, he took his chance, against striking the
blades, flinging with a quick jerk of his wrist that sent the detonator
straight through past the fan.

Hurriedly he climbed down and got the chair back in place as he heard,
muffled by the drop, a sharp explosion on the pavement in front of the
laboratory.

He was certain that the noise would draw everybody.

In the space between the outer and the inner light door he listened.
Doctor Ryder and Toby went with the rest. The way must be free.

Roger, emerging, saw that his guess had been correct.

There, poked up through the skylight coaming, was the long, and
large-girth telescope of Astrovox.

To an athletic youth, with agility and endurance, to climb the steadily
enlarging, inclined barrel was no hard task. Once at the top he got over
onto the roof with skilful swings of his body and flexing muscles
drawing him safely over the coaming.

Then he watched, unseen from below, careful to be on the side facing the
sun so as not to let his shadow reveal his position.

There he watched for an hour as Doctor Ryder and Toby returned, and
others came to the stock-room, but went away to await his arrival from
the dark-room. Their wants must not be urgent.

The vigil was fruitless, though.

No one entered the dark-room, barely visible in his quick glances.

A new idea came. He went up the rainspout of the adjoining roof, using
knees for grip and hands to pull him up from one bracing ring to
another. Down the adjoining fire escape he went, to the top floor of the
candy factory where, to the surprised girls, he whispered, pretending to
be mischievous, "Playing a trick on the folks next door." They all knew
him, from seeing him going to and from work. He accepted some candy, and
went down and out onto the street.

He saw no one watching. The brown mark of the torpedo detonation was
still on the pavement. He slipped into the laboratory cellar, by way of
its ash-lift, unobserved as far as he could tell.

To the air-conditioning system he made his way, trying to see if any of
its outlets, especially one to the dark-room section, had been removed
or tampered with. He saw some signs that a pipe wrench had ground rough
bright spots on the piping, and smiled. His idea had been right as to
where the gas had been sent up. A survey among old trash awaiting the
attention of Potts revealed a large, empty tank. Some one must have
charged it--whether by purchasing the materials or by injecting the
exhaust from a car he never found out.

There, though, was his evidence. He left it as it was.

Grover had been right.

Some person or group, with intentions far more vicious than had been in
evidence among the Tibetans, had marked him. Why? What did he know? Not
the place of the lost Eye of Om. For that they would want to take him
prisoner, to question him. This attack had been because someone was sure
that he knew more than he did.

Could he find out what he was supposed to know?

To try was Roger's immediate intention.




                               Chapter 33
                            A NEW SUSPICION


It was Roger's plan to consult his list of "sound" evidence and try to
make it tell him whatever secret must be hidden there.

No other plan seemed so likely to be fruitful. If he was supposed to be
in the dark-room, his presence in the office must show to some guilty
person that Roger was equally alert and crafty. He wanted to "start
something" in the open. Underground methods, secret attempts to do away
with him, were hateful to open-natured, frank Roger.

Strolling up from the cellar, he watched the effect of his arrival from
that unexpected quarter. Mr. Millman, discovering him, looked up with a
start.

"Hey! Thought you were developing the stuff Zendt took up."

Zendt--Millman. Roger connected the two mentally.

"Those speed pictures are important." Mr. Ellison scowled, and Roger
began to wonder whether his anger was genuine or if he, himself, was
giving too much importance to a mere annoyance.

"I was just testing my new 'cloak of invisibility,'" Roger put on a
careless manner. He would give _them_ something to puzzle about.

"Science is just the reality that used to be fairy stories," he said,
with a grin. "Pegasus, the flying horse, was just another way of
prophesying airplanes. And if a magician could wave a wand and turn a
beast into a Prince, doesn't chemistry transmute base elements into
wonderful, modern products? I got an idea that the cloak or helmet of
invisibility, like the Helmet in Wagner's opera that I heard on the
radio, is just the prophecy of some Omega-ray, that makes things
transparent and invisible without hurting them. It works, too. Did you
see me go out?"

"No," Mr. Millman snapped out the word, adding:

"But we _will_ see you go out--to the observation ward of the
psychopathic division in some hospital if you waste any more time with
this crazy talk."

Roger, thinking quickly, decided that he was hearing a threat. Millman
was not joking. If an astrologer, coming into the office, had recognized
the man, either facing him or hidden under the desk, and for that
knowledge had come near to being "sent West," then it would not be put
past such desperate people to believe they would deliberately put him
into the ward where supposedly insane people are kept, while doctors
studied their mentality.

That, he reflected swiftly, would effectively get him out of the way;
and it would discredit his ideas.

"I was only joking. What's the matter with everybody? Snap me up because
I chased out past you to see what the shooting was for."

"Well, get back to your work. Potts isn't here. It's up to you to keep
things going till the Chief says differently."

Roger looked defiant. He meant to see how far the man--or the pair,
would go.

Doctor Ryder and Mr. Zendt, who had evidently been conferring on the
upper floor about some biochemical condition of the disease the doctor
was studying, heard the raised voice of the electrical engineer and came
down the stairway.

"What's going on?" asked Doctor Ryder, twisting his watch chain, which
hung across his ample chest. Roger, who saw the big charm, which hung on
the chain, flicking its golden back in the light, realized, with an
inward start, that the doctor seemed to be telegraphing with that
"heliographic" flicker, as a Boy Scout would use a mirror to send a
message from his camp to another, from a hilltop.

"Oho!" Roger's mind was alert, "So he's telegraphing somebody."

He hid his smile of triumph.

"So you're in it, are you?" he mentally accused. "Well, two can play
that heliograph game. I can read if you can send."

While he listened to Mr. Ellison's angry commands to get that film
developed or the Chief would be called up, Roger mentally received the
flickers of the heliograph-like gold back of the twisting charm.

"B-e c-a-r-e-f-u-l."

"Warning him," Roger's mental comment was not audible.

"More?" He saw the charm continue, as if the doctor was nervous.

"R-o-g-e-r," it told him.

"He's warning _me_!"

Roger, grateful, and glad that his first suspicion had been unwarranted,
waited to see if more would come, while his facial expression was meant
to infuriate Millman and Ellison.

"B-e-h-i-n-d y-o-u."

Roger, turning his head, realized that there _was_ good intention
plainly apparent in that peculiar flicker-warning.

In the office doorway stood a stranger.

Whether he meant good or ill Roger did not know. But he swung sharply,
about to demand the stranger's right to intrude beyond the railing when
he saw that the stenographer, Miss Murry, had sent him in.

Roger, taking him in, saw a short, bald-headed, thin gentleman in a
frock coat, striped trousers and a high silk hat.

"I am looking for a Roger Brown," the man studied the group. "The office
girl thought I ought to find him in what she calls a dark-room up some
stairs. Can you tell me?"

"I am Roger Brown, sir."

Roger stepped forward.

"Can I see you in private?"

Roger saw that Doctor Ryder's watch ornament, emblem of a secret
fraternity, was flicking around again.

"S-a-y l-i-t-t-l-e," it seemed to counsel.

"I can take you to my cousin's private room, sir." He nodded to show the
doctor that he understood. "But I can say little about our work until my
cousin is here." He led the way to the private door. He had told the
doctor that he caught the two words.

"So you are Roger Brown." The man was seated in the "thinking den"
opposite Roger, who stood by the window and admired the sumptuous
limousine with its chauffeur, waiting outside.

"Yes, sir. How do you know my name, and what do you want to see me
about?"

"I know your name--no matter how. As for what I came about, I want to
dicker with you direct, instead of with anybody else."

"Dicker?"

"For the Eye of--er--Aum or Ohm."

"Why do you think you can dicker with me, Mister----"

The man did not reveal his name.

"You have the thing."

"Who says I have?"

"I know you have it, Roger. The point is," he glanced at his watch, "and
I must hurry--the point is, you got it. Somebody else offers to get it
from you and sell it to me but I think I may get a better price from
you, direct."

"Well, you can't. Who says you could get it from him?"

"Young friend of yours--Tobias or something like that."

"Toby Smith, huh? Well, he can't sell it because I can't turn it over to
him. Only saw it in the Buddha's head, and in a man's hand. Maybe Toby
already has it. Let's go ask him."

"Can't waste time. What's your best price?"

"Well----" Roger had an idea. "You leave your card and I'll get in touch
with you."

"I won't go higher than ninety thousand. If that suits, call up Clark,
on Fifth Avenue, and say you are ready to close. He will understand, and
will arrange everything. Good day."

Brusquely, abruptly, the man left. Roger let him go.

But when the limousine had drawn away, Roger marked down its license
number, and within five minutes, from the Bureau of Motor Vehicle
Licenses he had information.

That license plate on the limousine belonged to a wealthy man, often
mentioned in financial news. Roger, from a book of "Who's Who" learned
more; he was a collector, among other things.

But, Roger asked himself, was his wealth, position and hobby any reason
not to place his name among those suspected, or at least connected with
the Eye of Om mystery?

And Toby. And Clark. They came uppermost again.

If only he could get the hidden clue in his list!




                               Chapter 34
                         TRAGEDY STRIKES AGAIN


Without consulting his list, because he did not want to have it in sight
any more than he wanted its place in the files discovered, Roger used
the "thinking den" for just what its name implied.

"Claws on glass," he reflected. "Click of a contact. Voice of Doom
upstairs from Balsa-wood speaker. That's what the click was for. The
plug-in that made the connection through the house-wiring from record to
speaker-unit. The Voice again on a record that ought to have been
blank?"

He went through his list, mentally, to get all fifteen sounds clear in
his brain again.

"The call of 'Fire' and paper rattle sounding like flames," he completed
his silent inventory.

"Of course," he told himself, "the last one links up with the Voice of
Doom on the record, and that links up with the Voice out of the speaker
upstairs. And the click, as the plug-in was made is a link there too.
Then, again, the thump in the corner that made me start the picture
machine--that could have been disconnecting the plug-in. Doctor Ryder
had thought it was going to be more, for he was with me and cried out,
'start the machine' or something."

The clicks that he had first misread as dripping faucets in a
washing-sink, that had turned out to be the safe combination being
manipulated by an expert, he put out of mind as explained.

"The claws on glass hooks up with the film that showed the
ghost-kangaroo," he decided. "That can be side-tracked. Now, that leaves
the talk that named Clark, after the Voice of Doom--all three times it
could have been the same record, of course--what is left?"

He re-pictured his clues.

"The grind of moving rocks on the records. None in real rocks. A thump
on the record. How do they tell me anything? The record was not really
made in Tibet. It was made in America. I seem to remember that the Tibet
voice was deeper than the one on the record. But why did the record add
something not in Tibet? The rock rasp. Is that my real clue?"

Puzzling about it, and trying to see what link there was between the
thump and that additional grinding sound, he got no inspiration.

His meditation was interrupted by the arrival of a caller, a man from
the Museum of Natural History.

He wanted the laboratory to work out some extremely complete system for
protecting the museum's very valuable collections, such as the gem
exhibit, and other priceless collections.

Roger had to explain the absence of his cousin on "business" and to
accept the assignment conditionally on Grover's acceptance.

"Probably some short-wave system could be worked out," he said, and the
caller left.

Grover telephoned. Told of the call, he agreed to accept the commission
and would call at the museum before coming to the lab., when relieved by
Potts toward nightfall.

Roger went back to his broken thread of meditation.

An attempt had been made to get into his room. Millman had been caught.
His motive, he had said, was to learn whether Roger played scientific
tricks. Did that ring true? Or, as Roger felt, could he have wanted to
silence a tongue able to accuse him about Astrovox?

Roger tried to fit that theory in.

"It just won't quite come," he mused, despondently. "But I must be
considered fair game because I know something. There is the man who
thinks I have the Eye. Having it wouldn't make them want to get me out
of the way. Only the Tibetans would try that, and _not until_ I said
where the Eye is hidden. And I don't know. Still, I have been attacked
by some gas in the dark-room. Now what _am_ I supposed to know that
would reveal the 'who' in this?"

A shout from the upper floor broke his reflections.

With a sinking feeling in his stomach and with heart skipping, he opened
the private door and looked, listening, toward the stairs.

Millman and Ellison, Hope and others, were stampeding toward the steps.

"What was it?" he called.

"Doctor Ryder--something has happened----"

He joined the hurrying group.

In the partitioned room, among the cages and plant-housing, on the
floor, lay Doctor Ryder, with Toby standing beside him, his face looking
horrified.

"What is it?" Mr. Zendt came stamping up the steps.

Ellison, bending in a crouch over the prone figure, looked up.

"Did he faint?" he asked Toby sharply.

"N--no, sir. Just fell down that way."

"Are you--sure?"

"Ye--yes-sir."

Roger moved closer. "Is he--alive?"

"His pulse is very low, but he breathes. Now," Ellison stood up,
organizing them dictatorially, "Toby, bring ammonium--any form."

It flicked through Roger's subconscious mind that the electrician knew
chemicals. He had not used the ordinary, every-day "ammonia" but then he
had not added the word to indicate the chemical nature of an ammonia
solution. It might be because he was excited.

"Roger, have the stenographer call a doctor--or an ambulance from police
Headquarters is a quicker call. Zendt, what do you say this is?--Stroke?
Coma?" The bio-chemist bent down, squatted.

"Did he stand in front of that Beta-ray?" he asked Toby.

The helper, apparently very much frightened, perhaps afraid of being
accused of something, grasped at this eagerly.

"Oh, yes-sir. He was right in front of it, working on them new rats he
got in. Why? Will that lamp burn him?"

"Those rays may have a disintegrative effect, some reaction in the human
body. I can't say. I saw it was on, and asked."

If that was a solution, there was tragedy, but not a culprit--a careless
accident, instead, Roger mused.

Was Toby's word, he mused, having made the stenographer contact the
police--was Toby's word to be trusted. Or had he--what?

The ammonia, and chafing of wrists, had no beneficial effect.

Almost immediately a police car came; and soon afterward the interne
from the ambulance was examining the man who had been put on the
laboratory's emergency cot.

The doctor bent close, sniffed at the faint breath.

"Get the stretcher," he ordered abruptly.

"What is it?" Roger's voice shook.

"Poison, I think." He used their medicinal emetics as a first-aid
measure, but almost without waiting for effects, took the inert figure
away.

Mr. Zendt, standing reflective among the group of stunned laboratory
workers, suddenly confronted Toby.

"Did he--drink anything?"

"Y--er----"

"_Did he?_"

"I--no--yes, sir."

"Water?"

"Y--yes, sir."

"Did he get it himself--where? What glass did he use? A clean one?"

Under the fire of questions Roger saw Toby redden and then whiten, heard
him stammer and try to evade.

Out of it all came a sudden declaration.

"I never give him no poison. He told me to get him a drink. I went to
the cooler, and drawed water in the glass. I knowed it was clean. I
always get told about washing everything the minute it's done with, and
I did it even with the glass."

If he had washed the glass, no evidence or clue to its former contents
would remain in it. Was that, thought Roger, a way that a person might
behave who had put something in the water? Or was Toby, as he insisted,
innocent. But no one else had been there! Or had Zendt, formerly up with
the doctor, put anything in that glass perhaps intended for either of
the pair working there?

It was a maze.

And out of the staff, two were impotent.

Roger shuddered. A thought turned him all goose-flesh.

Might some one else be the next?

Which of them?

Maybe he, himself, might be.

Or--he thought--was it all over? Was the real culprit caught?

The police arrested Toby, took him away.




                               Chapter 35
                          THE STALKING TERROR


Roger left the laboratory. He located Grover. His recital amazed and
stunned his cousin.

"Astrovox unconscious still. Ryder hovering in the balance. Toby in a
cell." Grover summed up. "Two attempts to reach you--and why? Can't you
think, Roger?"

"I've mauled my brain, but I just don't see what I seem to be expected
to know."

"And the missing jewel," groaned Grover. "Where is it?"

"I haven't seen it since Clark put it in his pocket, in the temple,
Grover."

His cousin considered the matter as they took lunch in a quiet corner of
an uptown restaurant.

"You lock up securely and make certain that the devices all work."
Grover said, as they separated, "I shan't have to stay with the old man,
because it isn't expected that he will regain his wits for at least
several days. I must go to the museum. Business has to go on. Then I
will have a talk with Potts. We have given him what the French call a
'white card'--a clean slate. But--I want to question him. He might have
picked up the real gem. He could have realized what a find it was. He
may not have discarded it. And while I hate to suspect him--"

"But he wasn't there, today, when Doctor Ryder--"

"How do you know?"

Roger was silent. Like Grover he hated the idea; but Potts had been
free, supposedly resting. He might have been around. If anybody could
know ways to get in--oh, it was not thinkable, though!

Much more Roger preferred to mistrust the electricians, or the
bio-chemist.

On his way back he stopped at home to get the record carrying the "fire"
and crackles. He would need a fresh record for that night.

With his package he returned to the laboratory. Everything was quiet,
there. The men, in their activities, were sober but busy. Zendt greeted
Roger.

"How is Astrovox?"

Roger told him. It was suspicious, the young cousin decided, that Zendt
was so anxious. Less so, it seemed, about Doctor Ryder. He made no
inquiry, though Roger, coming in, had called up the hospital to learn
that the man was out of danger due to the prompt action of the interne
at the laboratory. He must be quiet, for ten days or, at least, for a
week, Roger had been told.

"Astrovox," he told Zendt, "is unable to say anything, and they don't
expect anything else for days."

That, he hoped, would "spike" any intentions the man might have to harm
the old astrologer. Not wishing to say more he hurried to the dark-room,
quickly put the waiting films in a time-and-temperature regulated bath
and went out of the place for the eighteen minutes that would elapse
during development. He busied himself clearing out the waiting
requisitions for minor needs from the stockroom, tested the glass used
by the doctor with no result, and then put the films in hypo. for
fifteen minutes, staying in the open rooms during fixing period and
washing afterward. He was not going to be caught in that dark-room, with
Grover and Potts away and some stalking menace quite possibly still
abroad.

His list was still in the file, he made certain. He had thought that it
might have been taken; but he realized that whatever was on the paper
was also in his head, and that was why he was endangered.

When it came close to closing time he helped clear away used trays and
other chemical apparatus, washing-up. He gathered up all films and got
ready for the next day's work. The developed and printed film he left on
the drying drums, not caring to stay long in the dark-room.

When, close to the office at all times, he was certain that the staff
was absolutely out of the building, he began a careful and thorough, but
hurried series of operations.

His decision to stay there all night, discussed with Grover, had finally
been agreed to by his older cousin.

At home, there was no way to avert the trick used before. The fuse box
could not be guarded unless they hired a Falcon patrolman.

That the laboratory was more impregnable had been proved the night
before by the effort used to enter. The fire, set off probably by a pole
carrying a light, inserted from above the telescope, had been assurance
that even the skylight was considered too risky by whoever had wanted to
enter. That one had set the fire, hoping that firemen would have broken
in, giving him--not her unless the stenographer was suspectable--a
chance to run in with them.

What _they_ could want (or what _he_ could want), Roger did not seem
able to decide. Not the laboratory's secrets. When the false gem had
been sought in the safe, nothing else had been disturbed.

Roger, determined to stay all night in the laboratory, made his
preparations with thoroughness and care in spite of his speed.

The old microphones set at doors, windows and other probable entrances,
he tested. The cameras he took out of circuit. They would not need to
record, because no one must get in to be snapped.

From the upper room he resurrected the old shadow-box with its panel of
lights, connecting them into circuits so that the least disturbance by
any microphone, even a vibration of its sensitive diaphragm by slight
sounds, would cut a relay and light the right lamp.

The connections of the magnetic plates he traced, to be sure no one had
cut a cable. Where they all came together at the transformer Roger
transferred the connection from the 180-volt step-up to the next higher
output. Anyone touching any plate must receive a 300-volt charge. He
would not risk anyone getting away, granting that such a one got past
the bolts he wired fast, as he did with window catches.

The fuse-box bothered him. If an intruder could in any way get in and
pull out fuses, perhaps all his precautions to hold them would be
futile.

Presently a solution of that difficulty came to his trained mind.

With the fuses left in place, he disconnected the cables that fed the
protective devices, wearing heavy rubber gloves and with rubbers on his
feet.

Taking that set of flexible cables back behind the furnace and to the
main box of the electric company input, he risked later censure for
tampering with their property by breaking their seal on the box,
throwing off the big, main switch, and connecting-in his cables to the
main line just within the input lines. He closed the box, sealed it with
the switch again in the "on" blades, and knew that any outsider must be
ignorant of his precaution. The fuses could be pulled, the wires at the
switch-boxes could be cut, and still his plates and microphones would be
actively charged, potent and effective.

Roger, effectively sealed in, he felt, sat down with the supper he had
ordered in, saving milk and sandwiches for later, and ate with a feeling
that he was safe.

Half way through the meal, with an inspiration, he took a charged wire
from the main-line up to the telescope still poked up out of the
skylight. He had climbed up. If anyone started to climb down--what a
shock that telescope would give.

Contentedly he closed his meal with a big cream-puff.

Soon after that darkness came. Roger, unwilling to discover his presence
by lighting a light, sat comfortably in Grover's "thinking den," and put
his thoughts to work on the problem of that list of sounds.

If he had only guessed it, his very elaborate precautions had been
overdone by just one protective effort.

Night chased the western glow away and brought stars to look down upon a
very quiet, apparently deserted building.

Roger, restless after an hour of fruitless thinking, wandered at slow
pace toward the upper floor, planning to start there on an inspection
route that would kill time and give new assurance.

He had not completely mounted the stairs when he heard a sharp, almost
explosive crackle. His eyes were dazzled by a flash as if it had begun
to storm and lightning had flashed. He stood, transfixed. The flash
died, and to his amazement he heard a queer sound as if splintered glass
were dropping, tinkling and scattering; and yet it was a muffled sort of
clinking noise.

He summoned his best courage and with shaking limbs crept on up to the
second story. There, looking around half-fearfully, he was more amazed
than ever. In the gloom, objects he knew well by location loomed without
any apparent change. The telescope pushed its long barrel upward, the
table and chairs, cabinets and cages, seemed as before.

He threw on a switch for light.

None came!

He stood there, baffled. Had the power-house cut off their "juice" or
had a dynamo cut out for the time? No. There had been that detonation
and flash. A torpedo such as he had made? No--more like the spark from
their high-tension transformer jumping a gap.

As he stood there, something below him went over with a crash!




                               Chapter 36
                            A LAW OF NATURE


Roger, in the dark, hearing the echoes of that crash, felt fright that
nearly swept him into unreasoning panic.

Not quite, though!

With every effort of will he held his muscles steady when he wanted to
run. Clear faculties would be all he had left to pit against an
adversary certainly more than simply vindictive. The unknown was almost
as brilliant in mind as was his cousin, Grover.

Grover? Why _he_ would have thought out that one and only way in.

Roger, forcing himself to be calm, realized at once how his extra
protection had been turned against him.

He had wired to the telescope. Some one, climbing the candy factory fire
escape, looking down from the roof of that building, could, by the angle
of view, have seen him attach that wire, peering down past the bulk of
the telescope. Thus charged, all the miscreant had to do was to lay a
wire or rod or any metallic carrier, from the candy factory drains or
rainspouts across to the skylight. By pushing it into contact with the
heavy charge in the telescope, a short-circuit could be established that
would blow even the main-line fuses.

Thus, and in no other way, could the devices have been rendered
impotent, the locks be only held by wires which a powerful implement in
hands so adroit could easily sever.

Even the alarms would not work. They had undoubtedly operated at the
instant of the break, and in time a Falcon patrol agent and anyone who
called police from home, would help him. But until then!----

He must, Roger knew, be his own protector.

At ten Grover would arrive, using a pre-arranged signal.

Not for an hour would he come.

"Self-preservation is the first law of Nature," Roger's mind in a
whimsical flash reminded him. Instead of throwing his faculties into a
turmoil, the imminent danger calmed him. That much Grover had made him
learn.

By opening a way in, the miscreant had, for Roger, made clear a way out.
He was, then, in no vital trap.

He could afford to drive back panic, to think carefully what to do.

If the whole building had been short-circuited, the telescope was no
longer charged. He had climbed it. Climb it he could again.

His problem, though, was to trap his unknown adversary if he could.

With no electrical help he must think out a plan.

It must be clever, Roger knew. His menace was from a man as brainy as
was his cousin. And that, Roger felt, was a compliment to a very
unjustified person.

He thought he knew what the crash had been. Something deliberately upset
in the cellar, to scare him. It had come about as long after the flash
as would have been consumed in rising to the roof on a rope, scuttling
down the fire escape, opening the cellar coal chute, and climbing down.

He estimated the time that had since elapsed. The adversary had by now
gotten up the cellar stairway and would be on the ground floor.

Would he come further or try to lure Roger down, the solitary youth
wondered.

He must let that become apparent by what his keen ears would detect.

He discarded all but attentive listening, making his mind focus on some
plan to trap his adversary.

What his mind had, with seeming whimsicality, obtruded during his moment
of terror, came back to Roger. "Law of Nature." seemed to prod at his
thoughts. _What_ law of Nature? How would it help?

Almost as though some inner monitor was going to save him, a mental
visualization of the laboratory seemed to become clear to his mind. He
saw the ceilings, with the slim pipes that ran here and there to
openings; and he connected the vision with the fact that their
fire-protective apparatus had _not_ functioned, when the alarm had been
set off. The tanks of heavy gas, under pressure, were still charged.

"Gravity!" Roger's mind grasped at an idea, "that's the Law of Nature I
am trying to think up."

As if he had received a key to a tantalizing problem, Roger solved his
course of procedure in a flash. In his mind he ran over their stock of
chemicals. Hydrocyanic acid, a stinging, powerful combination of
cyanogen and hydrogen; and hydrochloric acid--and many more.

One of these, akin to a tear gas, would do. But he was cautious, and in
spite of the pressing uncertainty he paused to be sure he would not take
for his plan anything that could, in combination with the
fire-smothering gas, cause an explosion.

Almost at once he had the solution. Sulphuretted hydrogen--the common,
refined gas that comes in the city mains from gas plants to stoves and
gas jets--_that_ would not explode in combination with the heavy gas in
the compression-tank system!

He wanted a gas that would stupefy: but he needed to be sure that it
would lie, close to the floor.

The gas in the fire-prevention apparatus was such a heavy gas that on
being liberated, under pressure, it would settle rapidly, diffusing and
spreading, as if it could be likened to a cloud, surcharged with
moisture, settled on the earth, enfolding it like a blanket.

There, in the upper room, was the means of releasing the city gas,
which, Roger knew, would stupefy of its own constituents--even kill, in
time. He did not intend to give it that much time! He merely had the
desire to put his assailant into a state where he could not leave.

Either the intruder was hesitating because of Roger's silence or he was
very quiet in his actions.

Roger, equally quiet, was extremely active. He had unlaced and had
slipped off his shoes at once. On stocking feet he tiptoed to the large
gas outlet set into the wall for use with Bunsen burners or gas heaters
used in experiments where a regulated heat was needed.

This he opened, full, by turning the valve one half a revolution.

Darting swiftly away from its low, humming release of a heavy flow, he
ran quietly across to the thermostat on the wall, connected into the
fire alarm and release system. Under it was a manual lever, one to be
operated by hand, in any emergency where the thermometer failed.

Swiftly Roger threw this on, and with his handkerchief tied over his
nostrils and back of his head, for already he smelled the gas of the
opened outlets, he swarmed up the telescope.

The house-lighting gas, he knew, would be held down, running to the
lower floor down the stairway, and the amount released would be enough
to stupefy quite soon. Even if the adversary climbed the stairs, he
would be in a bath of the sleep-inducing sulphuretted hydrogen.

With his arms and legs helping him rise, Roger clambered up the inclined
metal barrel of the telescope. At the top, above the flow of smother-gas
to kill fires, he paused, listening.

Not a sound.

To the roof he clambered, and sat on the coaming of their skylight,
looking down, waiting a few moments in case the other tried to come up.

Below him all was silence.




                               Chapter 37
                              REVELATION!


Soon Roger felt that he had given the gases time to flow down, to
produce at least inertia or coma. He must not dally too long. He
scrambled up the rain-drain as he had previously done.

Down the front fire escape of the candy factory he scuttled.

No one seemed to be near, as he gave a hasty survey.

Then Roger stiffened, on the lower stage of the fire escape. On the
other side of the street some one emerged from a doorway.

Hearing the man walk rapidly across, Roger dropped, landing in a crouch
that broke his fall.

He meant to accost the person openly, and risk consequences.

"Stop!" he shouted.

He got almost as great a shock as had come from the flash of the
short-circuited telescope.

"Rog'!"

"_Tip!_"

He recovered from his daze. A cold horror stole over him.

Potts, their handy man, around there. And no one else. Or--was another
inside? More probably, smelling gas, Potts had retreated the way he had
come, escaping.

"What are you doing here?" Roger demanded.

"Watching. Grover bid me to."

"Well, we will soon know. He's due at ten."

Roger pretended he had something in his coat pocket.

"You're covered, Potiphar. Don't try to escape."

"Me?" in surprise. "Are you batty?"

"Somebody short-circuited the telescope after seeing me wire to it, to
be sure no one got in to attack me. You'd know how to do that!"

"Oh, yeah?"

There would be a way to tell whether Potts was aware of the gas.

"Easy to prove you're innocent. Let's go in and search."

Briefly, not entirely, he stated the case, omitting the gas.

Potts drew back. "We ain't--armed. I see through your scheme, with your
hand in that empty pocket. Nix. I go in when we get a cop or somebody."

He might know about the gas and that would account for his lame excuse.
It was not like Potiphar, Roger thought, to shirk danger.

"All right. But I've got to get in and shut off that gas."

He had to let Potts go, just in case there was any other inside the
fume-filled lab. Roger, running to the drug store, where an ex-service
man was on duty as he remembered, begged him to find an old gas-mask.
The man hunted through some things in a back room, and gave Roger the
proprietor's old war trophy, which Roger, with his aid, adjusted.

Thus protected, and aware that Tip still waited, he ran in with no fear
of setting off electrified alarms, dashed up to the second floor by aid
of a flashlamp picked up in the office, seeing no one.

The gas he shut off hurriedly and then he set the thermostat lever back
in case the tanks held more unexpelled fumes.

Throwing wide all the windows on the ground floor, he wished that they
had current for the fans to blow out more quickly the gases.

Potts, waiting, wanted to quarrel about Roger's suspicions; but Roger
sent him to the drug store to return the mask and call the lighting
company, tell the rough conditions and get an emergency squad in to
re-fuse and seal their input boxes.

Grover came along about the same time that the truck finished and
departed.

Quickly, on the sidewalk, Roger recounted the situation.

With current on, in spite of the company's annoyance at this tampering
with sealed boxes, Roger, smelling less gas than would be dangerous in a
momentary invasion, set fans going and rushed out.

On the pavement they discussed conditions. Roger could not help feeling
that Potts was to blame, had been, in spite of all loyalties, in face of
past good conduct--Potts had been his adversary.

"He was the one who put the record on my home recorder, with the
fire-call on it already."

"How'd I know?" flared Potts, "I--it was with the unused ones."

"Oh, yeah?" Roger threw back at him his former grunt.

"Tip could have substituted an exposed film for the unused ones, so that
we developed the animals. He could have taken the film to the zoo and
got the kangaroo, maybe with an ape. We can check," he insisted. "He
could have transferred the first culture meant for the rats to the place
behind Doctor Ryder's racks."

"For that matter, Grover could of did any of them. He could have as much
cupola as me."

"Cupola?" broke in Roger.

"He means 'cupidity'," remarked Grover, "thinking about the Eye."

"But _he_ says he found it. Admits it. And Mr. Clark vows he had
blundered, and threw away the good gem," persisted Roger, sure of his
incriminating clues. "Who says the gem was left in India? Who had the
sense to pull fuses, to stop our devices? Who else but somebody trained
by you, Grover----"

"Well, _you_ was trained, too," cried Potts, angry.

"The gas is expelled by now," Grover had not lost his cold, serious
expression. "There is desperate need for action, more than for
recrimination. Let's go in."

They sat in the office. Roger recounted the clever warning with his
watch charm on its big chain, given by Doctor Ryder, and all the
mystifying, or incriminating conversations and occurrences, including a
fuller account of his experience in the dark-room.

"I suppose the poor mice are gassed," he muttered, finally.

But Grover was not listening.

"Tip," he stood up, "help me push this desk aside."

Potts did as bidden.

"No shot was fired in here," Grover snapped. "When Astrovox was later
assaulted. What happened, Roger? Don't you know? And _you_ exploded a
torpedo to call attention to a certain place and away from some other?"

Roger was all at sea for a moment.

"Astrovox was leaving. The other fellow didn't know that." Grover had
caught some clue or hint, somewhere. He was as active, as alive, as if
he had never been a cold, precise, restrained scientist.

"Some one wanted us all to run here. As he produced the summons,
Astrovox ran in. The man realized that he was recognized. Poor Astrovox!
Well, he will recover. And--see there!"

He pointed to a brown, scorched spot under the far edge of the desk as
it had been before.

"A foot, on an explosive, such as your torpedo, Roger. Evidence out of
sight. Evidently had no time, later, to remove the burn, but did remove
the exploded detonating cap. Rubbed his shoe over it. See the scorch?
Test and you will get something like a gunpowder reaction. Maybe you can
scrape up dust that would test out with the nitric acid to show the
stains of explosive gases."

Of a sudden he straightened up.

"The acid test!"

Roger, and Potts, gaping, had no way of following the swift deductions
which the Mystery Wizard, on the trail at last, made.

"Roger--no, Potts, you do it--run out and bring a taxi. Roger, you go up
and watch in the stock-room, but keep out of range of any missile sent
through the skylight."

He began writing as Tip rushed out and Roger obeyed. On his way, as
Potts came racing back, Roger heard, "Go to that address. Bring every
shoe you can dig up. And get what's written below, on your way back."

He locked the door after the man departed. Roger heard the alarms being
re-set. Then his older cousin joined him.

"What told you?" Roger knew that the Mystery Wizard was, at last, living
up to his name.

"Claws-on-glass. Think. That was one big error. You have told me the
truth."

Roger was baffled. He saw nothing that he had said which linked up with
the queer, sizzly, scrapey, frying and clicking sound.

Grover, with the upper floor extension plugged in, made call after call.
"Grover Brown, calling Chief of Police--hello--that you? Chief, we're
going to have a round-up at the lab." The usual calm was nil-minus.
"Will you?--Glad if you come with the men--I will ask you not to let the
men be seen--Wait at corners, across the street--Watch the skylight of
our roof for a blue signal--Yes, then come in a hurry--Good-bye."

To Roger's stupefaction he repeated almost the same instructions to the
men from Tibet, adding, "And--I promise to return to you the genuine Eye
of Om--Good-bye."

"But what told you, Grover?"

Grover glanced at his wrist-watch.

"The one clue that no one else could furnish."

He stood erect, alert, his eyes glinting.

"We've got work to do. Let's get going!"




                               Chapter 38
                               THE VIGIL


"Blue glow," Roger gasped. "Are _you_ going to have fireworks too?"

"No. You will adjust the big sun-lamp so it sends rays upward. Put the
blue filter from the star-reader's plant beds on it. It is only fair
that part of his equipment should help catch and round up the one who
struck him."

Roger, with nothing but thoughts to occupy him, went to prepare the
signal. He could hear Grover making calls. To a police Bureau. To his
staff men. To Falcon's patrol agency.

To Roger it appeared to be as dense a mystery as ever; but to his
brilliant cousin something had torn aside the fog.

He tried to fathom that evasive clue. He went over his ideas. Claws on
glass? No! Then what, besides? Something he should recognize in the
light of what he knew. Something that the miscreant had imagined him
bright enough to have guessed, perhaps.

It escaped him, eluded his every attempt to read that riddle.

Only a short time was he allowed to concentrate.

There were hookups to be made. A chair in the store-room was to be wired
down two legs, positive and negative wiring, a plate of metal as thin as
possible was to be found and put on the seat, with small clamps to hold
it in place under a thin covering cloth. It was to be left where it
stood, but two wires must be taken from a wall outlet, led to small,
flat disks like microphone diaphragms, tacked onto the floor at a place
Grover designated.

With that done and the wires fixed in a plug-in to fit the outlet, Roger
left the circuit disconnected as ordered, and busied himself leading
wires from the sun-lamp, with its blue cover-glass, to the stock-room
shelves where they must be so set that a can of film, shifted and
dropped over them by hand, would complete the circuit, act as a switch
to light up the sun-lamp.

Grover came up, inspected, and pronounced the work well done.

"Now, get a nitric acid test-bath ready, in a big container--and have
some wax melted and ready for the test for exploded gases."

"Whose hands did we overlook?"

"No hands. Feet." Grover answered, alertly, and with a
smile--mystery-solving seemed to transform him from a staid,
self-contained scientist into an eager, boyish experimenter.

"Shoes?"

"Exactly."

"His?"

"Right."

"Then--whose?"

"If you are too dull to have read your own sound clues, Ear Detective,
far be it from me to dull your wits by telling. Think!"

Presently Millman, Zendt, Ellison, Hope and several other staff men, in
pairs or alone, arrived. They were eager, excited as they questioned.
Grover, picking Roger's list of clues out of his file, presented it and
suggested that what he had learned they could learn, while Roger
recounted his own experiences up to date.

That was done; and they pored over his list. Grover, getting a lot of
amusement out of their guesses, chuckled to himself; but his younger
cousin felt that he was watching them to see when the guilty one would
crack and admit that he was cornered.

Who, besides, could be guilty? Doctor Ryder was in hospital; so was
Astrovox. So, in jail, Toby Smith was out of the night's excitement.

To his amazement, a police car, arriving, brought an officer who brought
in the last captive he had been thinking about--Toby.

The men seemed to have found no light in Roger's list.

Roger, who had heard their sane, or wild surmises, suddenly sat up.

Some brain cell, stimulated by the continual stress of cogitation, spoke
its concealed message.

"I know--Grover--how dumb I've been."

He scribbled a name on a slip from the office desk.

Grover nodded.

"You should have seen--heard the right answer long ago."

"I left it for the Mystery Wizard, so he could keep up his reputation,"
grinned Roger.

The Tibetans walked past, identifying their presence, but went on down
the street. Grover, watchful, looking out of the window, made a signal
that he had noticed them, and then suggested that they all go up to the
stock room.

There, in the silence, with no light except that in the monitor-panel
which Roger had set up to show which entrance was used when they could
expect callers, they sat around, puzzling and trying to make Grover
speak, although any one of them could have been suspicious of any other,
the way they talked. A light announced the arrival of a visitor, but
Grover did not move. Potts, he knew, was coming; and his inference was
the right one.

Potts, with a bagful of shoes, came in and dropped his find beside
Grover's chair.

"Take this chair, old fellow," Grover was very grave and had an air of
trying to make up to his handy man for Roger's mistrust; but Roger knew
that the chair moved over so casually had been most carefully set on two
small disks, not charged yet--but how easily so made active agents for
trapping the sitter!

"Now we must be patient," Grover stated, arranging the nitric-acid bath,
paraffin heater and other apparatus on a table. "I shall test some
shoes, presently, and I expect them to verify my judgment. In the dark,
though, I shall give the miscreant one chance to secure his Eye of Om
before I denounce him."

Someone, in the dark, shifted his feet, Roger imagined, uneasily.

"You don't mean to say you left it there!" It was Toby who made the
gasping admission in his sudden excitement.

_He_ knew it was there!

"Still where, for all your seeming denseness, you worked out its place,"
agreed Grover. "If you care to, you might apologize to Roger for telling
the millionaire collector that _he_ had it. Of course it was to avert
all suspicion from yourself."

"Aw--"

He did not have time to complete his denial or blustering cry.

A light in the tell-tale went out. The main door was opening.

"Nervy," commented Grover.

A strange, heavy thudding, or thumping, accompanied by something as much
like the drag of a heavy rope as any other sound, told Roger that some
weird development was coming. Could it be--really, a kangaroo?

And why, then, was there a strange chattering and jumping sound?

What would they see?

Those sounds grew louder. The stairway shook. Low growls or words of
command sounded.

Some animal, approaching. Or animals! No man--Roger was sure.




                               Chapter 39
                        THE APE AND THE KANGAROO


Whatever was in the laboratory, it was coming straight up to the second
floor. Roger, crouched beside the floor outlet to await a signal to plug
in and electrify that chair, wondered why Grover did not move the film
can, make contact and light the signal lamp to summon the police and the
Tibetans.

Instead, Grover spoke, low and meaningly.

"The first man who gets up is the guilty one!"

Zendt, who had started to rise, sank back abruptly. Ellison and Millman
stayed as they were, half bent forward.

"Guilty nothing!" Toby spoke in a rasping voice. "Think I'll sit here
and let something attack me?"

"You heard me," snapped Grover.

Roger knew that it would be a question of seconds only; and they would
then see the approaching creature.

There in the dark it was a tense moment, and a nerve racking one.

Louder, thudding on the floor, with a strange dragging sound at the end
of each pause, came the approach.

"Roger--that bag."

"The shoes, Grover?" in dismay. What was the matter with Grover?

"Quickly. That bag."

Roger lifted it, and Grover, snatching it, opened the paper sack,
dragged out a bulky object, just discernible in the dim light they had
from the tell-tale panel.

Roger gasped.

"Boxing gloves!"

"Lights!" snapped Grover; and as Potts, lifting an arm, snapped on the
wall switch just above the place his chair occupied, Roger saw his
cousin pulling on the padded mitten-like objects.

Whether the rest knew or not, that told Roger what to expect, if not the
whole situation. A kangaroo. A boxing kangaroo. The one he had
photographed when he had questioned its attendant who had said no pet or
trained animal had left the stable.

In the next room something stopped, and there came, not loudly, a low
command.

There was an interval of suspense. What, Roger wondered, was the
condition in that partitioned place adjoining their waiting room?

After a momentary wait, and more seemingly guttural commands, the
thumping was resumed; and the animal, in short hops, came to the
entrance door.

There it paused as if dazzled or surprised at the light or by the crowd.

Behind it, in the other, darker room, shown by their own light, Roger
saw a hairy, man-like creature, either chimpanzee or some other large
mammal it seemed to be. The kangaroo's keeper, he assumed.

Just as in the under-exposed film, where the ghostly ape and its
Australian companion had seemed to dance, the kangaroo hopped in, while
the ape, grimacing and beating its chest, danced in behind it.

Straight at Grover leaped the kangaroo. It wore boxing gloves!

Roger, crouched, tense and frightened, saw his cousin, with a typical
boxer's stance, prepare to carry the coming battle to his astonishingly
expert antagonist.

In that room, while the company shrank back, against walls, pushing
their chairs out in front of them, leaving a clear space, the animal and
the man closed in as fast and as bizarre a contest as Roger had ever
viewed. Not clumsily, but with lightning-quick jabs of its short
forearms the beast lunged, taking blows without a sound.

Grover, clever through gym training, fast on his feet, evaded the fairly
clumsy leaps and lunges. At every chance he got in a blow.

If, as Roger inferred, the ape was indeed the trainer, the bulky
creature bore out the idea. Grover had to watch the skipping, leaping
hairy thing that tried to get around and catch him; and also, as far as
Roger could discern his cousin's tactics, Grover seemed to be so
handling his leaps and side-wise ducking that the ape would be mostly
near to Potts who sat, tense, but still, in that chair; and Roger,
crouched by the wall outlet, wondered if he, the handy man, meant to
take part and if Grover had foreseen it.

"No you don't!" Grover seemed to be talking to the kangaroo, but of
course it was the ape he really meant to have hear, Roger knew.

"You keep far from the cabinet. What if it is ... och--oh! Missed me,
old fellow ... even if it is unlocked."

As though telling a story as he dodged and ducked, Grover always talked
as he maneuvered, his breath well conserved by his ease of action.

"So there _was_ a scientific student who turned to jewel theft! ... he
did want to get rich quickly ... he was clever ... made a specialty of
locating ... prized gems.... Through a jeweler named Clark, he ... he
got into contact with those ... who would pay well ... got the gems ...
used the jewelry place as a clearing house...."

In that fashion he began outlining a solution.

"Heard of the Eye of Om, didn't he?... Went to Tibet, taking Toby ...
didn't dare make a stab for it, though...."

Grover jumped back so that the monkey missed grabbing him.

"Got through Clark a man ... who would pay fabulous price for that Eye.
And ... worked out plan to have it so cleverly stolen _for him_ that he
would never be suspected by Tibetans or other gem thieves ... oh, you
would, eh?..." as the ape made a lunge and Roger, avoiding it, had to
drop to his haunches to avoid the boxing kangaroo's leap and stroke,
"Would, eh?... try to get to that cabinet.... Like to paw the Eye of the
Buddha, eh, would you?" as the ape started to take a part by coming up
to grasp him from behind. Roger was about to shout, but he saw that
Grover, like an eel, slipped aside. He did not strike at the ape.

"The gem robber knew he would be suspected if he ... took the Eye ...
returned to America ... made an elaborate plan ... would use science ...
chose our lab...."

Grover, his cousin saw, as did the rest, kept maneuvering so as to keep
the lunging paws approaching as he backed around. For some unseen
purpose he seemed to be manipulating his actions so that he could get
the ape and the kangaroo into some desired relationship or position.

Roger, still at his place, not daring to desert his post, saw the ape
back toward Potts.

Instantly, as though by some previous order, Potts snapped his body out
of the chair, and with his arms, catching the thing that walked upright
like a man around its torso, he dragged its shaggy body backward off the
huge feet and flung it into the chair.

"Plug in!"

Still dancing backward from the leaping kangaroo, Grover shouted. Roger,
checking the tremble and shake of his excited hands, swiftly drove home
the prepared plug and at the same instant from the thus electrified
chair rose a sheer animal howl of pain and fright and fury.

Still alert, Grover had a moment to catch his breath.

As if startled, the kangaroo paused. On haunches, its forepaws were
hanging down over its pouch--it was a female with the pouch to carry its
young!--while from the chair came the most ferocious grunts and
screeches. The trainer, thought Roger, was an actor in spite of his
surprise. He maintained the animal voice well.

As if prepared for the situation, Potts dragged from a pocket some
light, strong electric wire, and with gloves of rubber which Roger had
seen him getting ready, he managed to get the wire around the beast, or
rather, as Roger put it to himself, the man in the animal hide.

"You can cut the plug out, now, Roger."

Grover, with a wary eye on the still quiet kangaroo, which had not
moved, spoke the command. Roger obeyed.

Released from the shocking cycles of current, the thing in the chair
growled and struggled against the bonds which Potts had cleverly wound
to prevent use of arms or legs. So powerful, though, was the beast, that
it once upset the chair and had to be righted, growling and using
guttural imprecations or shouts of hatred.

"To go on with my story," Grover calmly confronted the quiet kangaroo,
"the man chose our laboratory as the base of his plans. He came here. To
start his operations, he watched his chance one night, and hid in our
large refrigerating unit, that is in the spare-stores room, since we
used it to test chilling processes for food shipments.

"Being unsuspected, he had been able to make certain preparations.
First, he put the culture intended to inoculate some white rats, into
our chemical section, half-hidden, but purposely left where it could
throw suspicion on a certain person. Then, when the rats had been
inoculated, but with a harmless drug that made them sleep, he was ready
for his next step."

To Roger's surprise, everyone had been so amazed and so startled by this
calm recital aimed, apparently, at a dumb brute that sat back with
drooping, glove-shrouded forepaws and listened!--or was too baffled by
the capture of the trainer to continue the battle--the staff had settled
in the chairs again.

"This mysterious, clever criminal," Grover coolly proceeded to tell the
animal his theories and deductions. "This former student of various
biological, chemical and related subjects, bribed an animal trainer who
had a vaudeville animal act, to let the animal used in the act come
here. He wanted it to be caught if any plan failed, so he could
disappear but the animal could not tell on him."

He bent forward, and quietly removed the laced ham-like gloves from the
beast's relaxed paws, and it seemed not to resent the act, but let the
free forearms hang loosely across its stomach, and pouch.

"Borrowing the white rats from the act, this miscreant prevented them
from being inoculated by exchanging labels on the culture, later
recovering the labels as the bottles emptied were thrown to the fire.
The labels, on the real culture again, were put where they would seem to
clear someone by incriminating him through circumstantial position in
the racks. Really, though, they had a different purpose."

He startled all but Roger.

"The appearance was that the man whose rack they occupied was being
persecuted. In reality, he did it himself, to make me suspect every
other staff man."

"Not Doctor Ryder!" Millman gasped.

"You have named the culprit."

"But he's poisoned, in the hospital----"

Grover went right on, ignoring Ellison's shout.

"He confused us by 'stealing' the rats, and in other ways, because he
wanted us to think of every possibility but the real one."

"And that was?----" prompted Hope.

"He wanted us to help him take a false imitation of the Eye of Om to a
Tibetan temple, replace it for the true one, which he could then sell
for a great sum. In other words, what we thought we were doing, helping
restore the true jewel, was exactly the reverse!

"We innocently helped remove the True Eye of Om!"




                               Chapter 40
                     THE MYSTERY WIZARD'S SOLUTION


While the beast shackled in the chair kept up its hoarse growls and
struggles, Grover outlined, for the benefit--it seemed--of a
kangaroo--or the one in the chair--his deductions.

"Was that clever? You know it was. To plan to steal a sacred gem under
the pretext of replacing a fake one with the true Eye."

Roger had not guessed that, nor, by the exclamations, had the rest of
the group--or most of them.

"The mystery of the white rats, supposed to be deadly menaces because we
thought they were inoculated with germs of a spinal malady, got our
attention turned to every possible idea but the real one.

"To add to our consternation, give a ghostly touch with the animal
'spooks' on a film, this clever thief made a record of what he recalled
about the Tibetan Buddha's 'Voice of Doom.' Like most criminals, he
overshot his mark, adding the grind of rocks, when in truth there was no
such grind. The sound was caused by wind, always howling across the
Himalayas, coming through a wind-tunnel cut in rock from the base of a
cliff to the lamasery temple on its crest.

"He made a record, with moans, cries and groans, and added the effect of
the rock closing, from his imagination of what would be right."

That record he had managed to slip onto their own recorder-reproducer
machine, with a hookup which Roger knew all about, Grover went on. The
weird manifestation had startled them, while watching for the man, one
night. With a Balsa-wood speaker hidden flat on a dusty shelf, he had
caused a spooky voice to draw them up where the prepared film, in a can
carefully re-sealed, was handy to be taken and, later, developed, to
complicate mysteries further with the spooky animals, he added.

"That was all for the reason that he had to bring in Tibet, logically,"
went on Grover, "he had to prepare us for the fact that he was in danger
from the Tibetan vengeance. Of course, by this time, the staff knows, as
we do, who I refer to."

Of course, Roger decided. The others nodded. Who, but the guilty man he
accused, could be meant? He had said the man was menaced.

"Doctor Ryder was the only one who claimed he was threatened," said
Millman, "and I suspected Roger of playing jokes!"

"Well, I suspected you when you came to my room," retorted the youthful
listener.

"And I did not know whom to suspect," Grover took up his story. "Clues
pointed this way and that. Appearances are easily falsified and I tried
to dig past them to truth--only, I lacked the right hint, and never
dreamed that a gem was to be stolen under the pretext of restoring it!
That was easily planned, for once the gem had been seen, perhaps
photographed with a watch-camera or some small photographic device, a
man like Clark, working with him for a share of the profit from various
gem sales, could reproduce in imitation the green jewel."

Toby, he inferred--and the youth eagerly attested the truth of the
inference--had been paid well, being a former helper at the Clark store
on Fifth Avenue, but out of work--had been paid to sell the supposedly
"real" Eye, its facsimile, for an absurd amount, as he had accepted a
movie camera.

"I fell into the lure," Grover hurried along, "because, for a time, the
Tibetan Voice of Doom manifestation, and the robbery of our safe,
confused me. It was easy to do that last by de-fusing our cellar
switch-boxes, a point I had never thought of. Scientists, like
criminals--or average people--trip up often enough on some minor point
in a plan."

Because the radio would allow him to be in touch, and for the sake of
the travel, adventure and scientific aid Roger would get and give, his
older cousin confessed that he had been glad to see Roger help the
supposed replacement of a sacred relic.

"Clark was brought in cleverly by use of a record. It was the same one
that had been used for the Voice here, and when the needle was dropped
onto the unused part, it made a thump that was one of the sounds of a
series of clues which puzzled Roger and me, because the _appearance_ was
that it was all one recording.

"The trip to Tibet went off as scheduled. Roger, really a sort of 'bait'
because of his youth, was, as hoped, taken up to the lamasery as a sort
of curiosity--a young American well up in scientific methods and
operations. Innocently he played the thief's plans, and still the very
apparatus that he insisted on taking there made the lamas suspicious,
especially one of their wiser men who had been out of their country, who
understood English, and who had read Roger's memoranda of radio talks to
and from lamasery and camp.

"With Tibetan vindictiveness, they let him hear the Voice of Doom,
probably operated by a concealed priest in the hollow image, and then
consigned him, and Potts, to the tunnel. By sheer wit and scientific
knowledge Roger found that he was in a sort of whistling tube, operated
when the rock door was opened, by wind. He worked out, with Tip's wise
help, the secret, and they escaped.

"Clark, when Roger got to camp, took the supposed Eye and with Roger
watching and unsuspicious, actually replaced the true Eye with the false
one he and Ryder had brought along. He had another, and to make Roger
think he was genuinely through with the stone, so as to be clear if any
Tibetan revenge developed, he threw away one more imitation. Potts,
worried about the levers having been wedged which he considered an error
of judgment, went back to repair it."

So interested were the men in following the developing solution that
they had forgotten how bizarre was this relation of a mystery and its
unveiling--to a beast.

The animal seemed fascinated, or cowed, or subdued in some way. Perhaps,
thought Roger, the plight of the hidden keeper made it tame.

Grover drew his theories into shape.

"Naturally, with the real gem, Clark and Ryder made all speed to radio
the prepared airplane. It met them. In Bombay, as he had no desire to be
further involved, Potts discarded the false gem he had picked up."

Then, proceeding on pure deduction, Grover felt that the Tibetans had
discovered their real loss, had discerned that Roger and Tip had solved
the intricate tunnel secret and had escaped. To write, with Roger's
discarded note book as a guide, in a semblance of his writing, was easy.
The letter had come by fast mail steamers and had further confused him.

"Then the thief, with the gem in his fellow-worker's possession,
encountered difficulties," went on Grover; "the man who had been
intending to buy the jewel probably became frightened, afraid of the
danger that the stone might bring around him. So many priceless jewels
carry curses, or bring disaster, that he must have gotten 'cold feet'
and a new buyer had to be sought. The gem, also, had to be secured, in
case the Tibetans actually put into action their vengeful methods.

"Toby was working here. Ryder thought it a clever plan to have this
former aide help him, and so he concealed the gem and had it innocently
delivered here, but Toby, not as dumb as he was considered, suspected
the truth, discovered the hidden gem, and on his own hook offered to
sell it to a buyer he had known at Clark's store.

"That made it necessary for Ryder to recover the gem quickly from the
concealment no longer unsuspected here. He tried to get people away from
upstairs, by detonating with his foot a torpedo under our office desk;
but Astrovox, our scientific star-student, had been about to go home,
frightened by some foolish combination of star-positions and a
manifestation planned to scare him away. He walked in before Ryder could
hide, recognized him--and the desperate man struck him.

"Soon thereafter he realized that in a list of some fifteen sounds made
by Roger there lay the actual clue that incriminated him and no one
else!"

"What was it?" asked Ellison anxiously or eagerly, Roger told himself.

"What Roger thought was claws-on-glass. His very first sound-clue. With
that on a list, and in the clever head of the stock-room clerk, Ryder
had two things to do quickly. He must get the gem, and he must either
find a way to throw suspicion elsewhere or get Roger out of the way."

Roger realized why many attempts had been made, like the one in the
dark-room.

"I warned Roger. Ryder, when Toby--who knew where the gem
was--telephoned him that he had left explosives out in the open--Ryder
tried to use that as a way to lure Roger here to open up, because we had
so arranged things that actually no one could even enter and not be
caught--he was deadly afraid of being electrocuted too soon.

"But Roger is still safe, the gem is available, and so--as you well
know, there is no more mystery, except this:

"How do you think you are going to get the Eye of Om--now?"

Roger stared at his cousin. Saying that. To a beast!




                               Chapter 41
                             MAN AND BEAST


With his mocking smile Grover walked over to their safety cabinets,
unlocked and threw one wide open.

Roger, with Potts, sidled over near the door, to block the beast if it
had been taught to snatch anything in its paws and hop away.

"No need," Grover laughed, "with its partner, the ape, bound. There is
no way to get out of that hide." He gestured toward the cabinet. "There
it is, just as you hid it, the True Eye, in a can supposed to contain
medicating compounds to use on the rats. Clever, just as was entry into
Roger's room, with the 'Fire' record, by that often-used idea of the
pulled fuse. I have wondered why you did nothing to him. Or did Millman
come along too soon and scare you off?"

He paused, and they all stared. Could Grover have miscalculated, Roger
wondered, in implying that the kangaroo was the impersonator? He had
assumed it was the ape.

The beast, on its haunches and flatly extended tail, reached two clawed
paws upward, caught one of the round cans from the front row, and
dropping it in the loose pouch, in the skin, turned and started hopping
toward the door, its claws upraised.

Grover, as it moved toward the chair occupied by the ape, deftly caught
its tail and swung an end around a chair leg.

"Shall I turn on the current?" he chuckled.

The animal became quiet, stopped.

Once only he tried to escape and when Potts made a move to obstruct the
way Grover calmly waved him back.

"But he's got the can, Grover!" Roger also stepped forward.

Grover actually grinned at them.

"Let him go," Grover waved back Potts and Roger as the thing began to
hop toward them and they made preparations to try to stop it.

"The Doctor," went on Grover as the animal paused an instant, "to get
Toby where his word would not be trusted, to remove him from the
laboratory before he could take away the gem he knew about, planned his
own poisoning this morning. He sent Toby for a drink, and by swallowing
some quick-acting sedative, perhaps strong codein, or another of the
poppy derivatives, he seemed to be poisoned. To make it appear like
strychnine or some other--wait! I'll venture to assert that in the other
room Roger will find the shell of some pit such as you crack in a peach
and extract a tiny kernel. Those inner kernels of a peach pit, chewed
up, would leave on his breath just the same odor as a very dangerous
poison which I shan't name."

Later that was verified. Roger found the cracked peach pit.

"It was easy to 'recover' and come here tonight," Grover ended.

He stood, looking with a mocking smile at the crouched beast and the
bound animal. The latter, quiet for a moment, growled deeply.

"The ape, trained at a certain point, to unfasten the kangaroo-skin so
that Doctor Ryder can wriggle out of it, can't help," he remarked. "Oh,
yes," to Millman's question, "the ape is genuine, a well trained animal.
The kangaroo--shall we help him?"

He walked over, and with a quick motion pointing out the laced
arrangement of eyelets under an armpit--or forepaw--he dragged the
lacing apart.

Revealed, it was seen by all that Doctor Ryder actually was in the skin,
crouched down as the size of the animal compelled him to be so that he
could barely get his forearms into the front paws.

The head, too small to hold his own cranium, was fixed almost in one
position by supports, and eye-holes were cut lower in the skin, well
concealed by the way the skin of the chest was sewed and the animal hair
arranged.

"He rented it from the animal trainer, who sometimes put it on, and
played the part of his own animal in the act if the kangaroo became too
fractious or when it was ill in our varied climate as they travelled
from theatre to theatre."

Cramped, scowling, Doctor Ryder emerged.

"Very cleverly worked out," he growled. "Yes, it is all true. I did plan
to have your laboratory staff help me steal the Eye, just the way you
have it worked out. And if it had not been for Roger, almost at the
beginning thinking of developing a sound-film I had neglected to put out
of commission, you might not have found out."

"Probably we never would," Grover agreed, and as bluecoats came tramping
up the stairs, with a man who went at once to his animal, and with
soothing words quieted it, released and removed it, the Tibetan lama and
his cohorts came in.

"But what _was_ the sound-clue?" asked Millman, "the fire-cry on a
record supposed to be unused? I got that, you know. But it meant only a
prank of Roger's to me."

"Neither that, which revealed how the Balsa-wood was connected up, nor
the Voice of Doom, made by Ryder, here, but not traceable to him alone;
nor the click as he switched on the motor; nor the clicks as his trained
thief's fingers manipulated our safe; nor the rest."

"Well, what _did_ the sound that Roger described as claws on glass
really signify that linked up Ryder and not any of us?" asked Zendt.

The pseudo-physician, scowling, was twirling his watch-charm with
nervous fingers as he watched the Tibetans who scowled at him.

"He is showing you," Grover remarked.

"Don't you see?" Roger turned to Millman. "I got the right idea only
just tonight."

"The watch-chain? But----"

"You, Mr. Millman, and Mr. Ellison, were on the ground floor when the
man came down because he had seen the rich man arrive in his car, and
knew Toby had played false to him," Grover stated.

"Think," Roger hinted, "he twitched and twirled that charm so it flicked
light from the gold, the way a heliograph does."

"That, when Roger told me, connected him with the first sound-clue of
the scratching, hissing, clicking sound at first claimed to be a snake,
then supposed to be his kangaroo."

"Don't you see," interposed Tip, who was improving, by leaving out the
big words, "he had to bend over to get the rats out of the trap on top
of the cage. He brought the ape to unlace his disguise. And his watch
chain and charm scraped and rattled and slid on the cage, and our
sound-camera film got the sound from the microphone inside the cage."

"Of course--and no one else wears a chain and charm," agreed Zendt, "we
all have wrist-watches."

"Well, what's the use of holding me for all this?" growled the man by
the skin. He picked it up.

"I'll just return this--go on and arrest me if you have any charge you
can support with evidence that a clever lawyer can't break down,"
snarled the man.

"A sound record, through your own Balsa-wood device, and down to our
recorder, will do the trick," Grover smiled. "Made by you, just now,
when you admitted all my previously recorded accusations."

"All right. I'm licked. Good night, all."

He turned as if to give himself up to a policeman.

"He's got the Eye, in with that compound!" cried Roger, as Toby pointed
at the pouch in the Kangaroo skin.

"Oh, no he hasn't," Grover actually chuckled in triumph, "in the same
way that he substituted the prepared can of film for a blank strip when
he handed Roger the can to load the magazine--so his animal ghosts would
seem to appear on an unexposed film when developed, I substituted a can
of oxygen, hydrogen, nitrogen and a trace of ozone, perhaps, and a few
other gases----"

"Air?" gasped Ryder, shaking the can taken from the skin.

"A free sample of air that is no longer contaminated by the gas Roger so
cleverly used to drive you out--a ruse that enabled me to get here
before you could return in disguise."

The man was defeated.

He was allowed to remain only long enough to make Grover's triumph
complete by sending Roger to the cabinet to take down the can just
behind the place from which he had removed his false one.

Therefrom, the Tibetans were glad to receive, as they forgot all
animosity toward Roger, the true Eye of Om.

For his attempts on Roger's safety and his act toward Astrovox, Ryder
stayed behind bars a long time.




                               Chapter 42
                              CLOSING TIME


The Ear Detective, more favored than ever because he had been the means
of listing sound-clues, one of which had completely linked Ryder into
his crime, was busy.

Astrovox, well recovered from his blow on the temple, was going to
"shoot" the stars as they crossed over the lens of his telescope and
Roger was getting a sound-film into a camera.

"Why in the world did Ryder have to go to all that trouble?" the old
star-reader inquired. "How much simpler to have come in his own clothes.
More freedom for his hands, that way, and no need to bring the ape to
unlace his animal skin."

"He knew," Roger explained, "about out protective device, and by wearing
the skin and bringing the dancing ape, he would never be photographed
and he would fool us all the more."

"Well," remarked Astrovox, "you'll remember that Neptune--the planet of
deception--was opposed by Saturn, the planet of obstruction, and there
was an opposition of Mars, ruling explosives, with Uranus, which is, you
might say, the planet that brings up the unexpected."

Roger smiled to himself.

Good old Astrovox, he mused, with his oppositions and "aspects" and all,
was, still, a very clever scientist, and must be humored.

"Yes," he chuckled, "and if I remember all you told me, something like
this was in the 'horoscope' that day. The 'sixth house' has to do with
animals--smaller animals, and Neptune with larger ones."

"That is my astrological teaching."

"Well, Neptune is in that sixth house, and if Saturn is the planet of
obstruction it shows why the false doctor in his deceptive disguises,
would be obstructed or caught."

"Rats!" Tip snapped.

"Rats are under the sixth house," Astrovox seriously persisted in
apparently preposterous ideas, "and Neptune showed how the gas was used
and also how the acid test, when Grover applied it to the shoes Ryder
had worn, revealed in the paraffin cast the exploded gas of the torpedo
he had stepped on to attract attention just when I ran in and recognized
him."

"What explains _my_ denseness?" Grover arrived, with a special quartz
lens for some prism-and-spectroscope color work, "I was put off the
track at first because Ryder knew my favorite axiom, 'dig past
appearances that can be falsified, to find truth which is ever the
same.' He deliberately hid the culture tubes in his own racks, and I
fell into his trap, trusting him, thinking he was being victimized by
some one else. It made it possible for him to be here, operate the trick
with the Voice of Doom and hand Roger the prepared film supposed to be
unexposed, carrying his animal pictures that he took at a special
performance given him for good pay by the animal trainer."

"Your density was because Mercury was in the twelfth house, and squared
the moon in the third--wrong deductions."

"Maybe those 'houses' are true," chuckled Grover, "I know one house _I_
am going to occupy. My own home. For a good sleep. How about you,
Roger?"

"After I see that all our apparatus is fixed for the night."

"You go ahead," Potts grinned fondly at his chum, all suspicions
forgiven, "I'll see that everything er--uh--coagulates!"


                                THE END




                              The Mystery
                                 of the
                               15 Sounds


                                  _By
                              Van Powell_

When Roger's uncle offered him an opportunity to help in his scientific
laboratory while the boy's parents were in Europe, Roger jumped at the
chance. His uncle's laboratory--one of the most perfectly equipped--was
the most fascinating place in the world.

Even the latest scientific devices, however, could not keep out the
"Voice of Doom" which sounded hollowly through the laboratories in the
dead of night, or prevent the ghostly antics of the phantom kangaroo and
his ape-like companion. These and many other occurrences make THE
MYSTERY OF THE 15 SOUNDS one of the best boys' mystery stories of the
year.




                            _Books for Boys_


In selecting the books of this series we, as publishers, have tried to
present a varied assortment, which will stir the imaginations of all
boys. At the same time we have kept these stories from being
nerve-wreckers.

                             Herman M. Appel
  Secret of the Flambeau, The.

                            William Dixon Bell
  Sacred Scimiter, The.
  Moon Colony, The.
  Secret of Tibet, The.

                            Walter Butts, Jr.
  Brothers of the Senecas.

                              Graham M. Dean
  Agent Nine and the Jewel Mystery.
  Agent Nine Solves His First Case.
  Circle 4 Patrol.
  Daring Wings.
  Herb Kent, West Point Cadet.
  Herb Kent, West Point Full Back.
  Slim Evans and His Horse "Lightning."
  Treasure Hunt of the S-18.

                               Edwin Green
  Air Monster.
  Secret Flight.

                             William Heyliger
  Big Leaguer.
  Detectives, Inc.
  Fighting Blood.
  Loser's End, The.

                            Norton H. Jonathan
  Dan Hyland, Police Reporter.

                            Gilbert A. Lathrop
  Whispering Rails.
  Mystery Rides the Rails.

                               George Morse
  Circus Dan.
  Extra.
  Vanishing Liner.

                              John A. Moroso
  Nobody's Buddy.

                             Ambrose Newcomb
  Eagles of the Sky.
  Flying the Coast Sky Ways.
  Sky Detectives.
  Trackers of the Fog Pack.

                                Van Powell
  Mystery of the 15 Sounds.

                            Warren F. Robinson
  "G" Man's Son, The.
  "G" Man's Son, at Porpoise Island.
  Phantom Whale, The.

                          Lieut. Noel Sainsbury
  Bill Bolton and the Flying Fish.
  Bill Bolton, Flying Midshipman.
  Bill Bolton and Hidden Danger.
  Bill Bolton and Winged Cartwheels.

                            Harold M. Sherman
  Captain of the Eleven.
  Down the Ice.
  Interference.
  In Wrong Right.
  It's A Pass.
  Over the Line.
  Strike Him Out.
  Tahara, Among African Tribes.
  Tahara, Boy King of the Desert.
  Tahara, Boy Mystic of India.
  Tahara, in the Land of Yucatan.
  Under the Basket.

                              Wayne Whipple
  Young Abraham Lincoln.
  Young Franklin Roosevelt.


                      THE GOLDSMITH PUBLISHING CO.
                             CHICAGO, ILL.




                          Transcriber's Notes


--Copyright notice provided as in the original--this e-text is public
  domain in the country of publication.

--Silently corrected palpable typos; left non-standard spellings and
  dialect unchanged.

--In the text versions, delimited italics text in _underscores_ (the
  HTML version reproduces the font form of the printed book.)







End of Project Gutenberg's The Mystery of the Fifteen Sounds, by Van Powell