E-text prepared by Emmy and the Online Distributed Proofreading Team
(http://www.pgdp.net) from page images generously made available by
Internet Archive (http://archive.org)



Note: Project Gutenberg also has an HTML version of this
      file which includes the original illustrations.
      See 43683-h.htm or 43683-h.zip:
      (http://www.gutenberg.org/files/43683/43683-h/43683-h.htm)
      or
      (http://www.gutenberg.org/files/43683/43683-h.zip)


      Images of the original pages are available through
      Internet Archive. See
      http://archive.org/details/ouryoungaeroplan00port





[Illustration: THE FIGHT IN THE AIR. _Page 42._

_Our Young Aeroplane Scouts In Germany._]


OUR YOUNG AEROPLANE SCOUTS IN GERMANY

Or

Winning the Iron Cross

by

HORACE PORTER

Author of
"Our Young Aeroplane Scouts In France and Belgium."
"Our Young Aeroplane Scouts In Turkey."
"Our Young Aeroplane Scouts In Russia."







[Illustration: A. L. BURT COMPANY]

NEW YORK

Copyright, 1915
By A. L. Burt Company

OUR YOUNG AEROPLANE SCOUTS IN GERMANY




CONTENTS


        I. SAVED BY QUICK WIT             3
       II. A STIRRING HOLIDAY            13
      III. A THRILLING MOMENT            23
       IV. THE STOLEN PAPERS             34
        V. WHEN THE LIGHTS WENT OUT      45
       VI. A FLYING VICTORY              56
      VII. THE RAIN OF BOMBS             67
     VIII. ALONG THE BATTLE LINE         78
       IX. THE LUMINOUS KITE             90
        X. THE CARRIER PIGEONS          101
       XI. UNDER THE RED ROOF           112
      XII. THROUGH FIRE AND FOG         123
     XIII. CAPTURED BY COSSACKS         135
      XIV. A WONDERFUL RESCUE           146
       XV. DUEL TO THE DEATH            157
      XVI. DRAWN FROM THE DEPTHS        168
     XVII. A MIGHTY STONE ROLLER        179
    XVIII. TRAILS THAT CROSSED          190
      XIX. RABBIT'S FOOT FOR LUCK       200
       XX. WINNING OF THE IRON CROSS    210
      XXI. HELD IN WARSAW               219
     XXII. AN HOUR TOO SOON             229
    XXIII. A LEAP FOR LIBERTY           238
     XXIV. AGAIN THEY WON OUT           248



OUR YOUNG AEROPLANE SCOUTS IN GERMANY.




CHAPTER I.

SAVED BY QUICK WIT.


"HOLD on there, I want a word with you!"

Billy Barry and Henri Trouville, the Boy Aviators, were in the act of
climbing into a superb military biplane on the great parade ground at
Hamburg when thus hailed by a mild looking man in citizen's attire,
with face half-hidden by a slouch hat and a pair of huge, horn-rimmed
spectacles.

There was a note of authority in that voice, gently tuned as it was,
and behind those spectacles were a pair of eyes as keen as gimlet
points.

The speaker was none other than Roque, the noted secret agent--"Herr
Roque," if you please, fitting into his masquerade as a merchant having
contract business with the authorities of the canvas city of aëroplane
hangars.

"Come over to quarters for a few moments, young sirs, won't you?"

The polite manner of request was for the benefit of the bystanders, who
had been awaiting the flying exhibit, but the slight gesture that went
with the words indicated a command to Billy and Henri.

They knew Roque!

Heinrich Hume, aviation lieutenant, who usually had a good deal to say
on those grounds, made no more protest than a clam at this interruption
of a special aëroplane test. He simply waved two other aviators on
duty into the machine, as Billy and Henri marched meekly away with the
imitation merchant.

While many of the spectators marveled at the apparent breach of
discipline, the lieutenant was content to let them wonder. At least, he
offered no explanation.

Billy and Henri did a lot of thinking as they crossed the parade
ground--there must be something brewing, or Roque would not have been
so impatient as to invade the parade ground at the time he did.

Roque conducted the boys into Lieutenant Hume's private office at
headquarters, closed and locked the door behind them.

Removing his spectacles, and throwing his slouch hat among the maps
that littered a big table in the center of the room, the secret agent
at the same time changed his form of address--the oily manner was
succeeded by abrupt and stern speech, which showed the real man of
brain and unlimited authority.

The secret agent had seated himself, without invitation to the boys
to do likewise. They stood, facing the real Roque they knew by former
experience.

"Where is Ardelle?"

Roque put the question like a pistol shot, and fiercely eyed the
youngsters before him.

The point-blank query failed to reach the mark intended.

Billy looked at Henri and Henri looked at Billy, and then they both
looked at Roque with never even a quiver of an eyelash. They had not
comprehended what was behind the dreaded agent's snapshot at their
nerves. The truth of the matter was, they did not know anybody by the
name of "Ardelle."

So Billy, with a bold front, remarked: "You can't prove it by us, sir.
Mr. Ardelle is not in our list of friends."

"None of that!"

Roque pointed a menacing finger at the astonished pair of youngsters.

"I have it beyond doubt that Ardelle was on these very grounds a day or
two ago, and by the word of a man who could not be mistaken. Fool that
he was not to be sure at the time, and only the garb of a sailor to
mislead him."

Then it jointly dawned upon the minds of Billy and Henri that Anglin,
the smiling secretary of the eminent director of affairs at Calais,
and later in the rôle of a bubbling sailor here in faraway Hamburg,
must be the Ardelle about whom Roque was talking.

They realized, too, that through their boyish delight in lending aid
and a helping hand to one they had known in intimate association with
that best of friends in France, they had unconsciously maneuvered
themselves into a dangerous game, a slip in which meant a dance with
death.

A tissue message from this very suspect that Roque was so eager to
apprehend even then burned against the breast of Henri, a little wad of
paper that now represented the price of the world to a pair of bright
boys.

Condemned of mixing in the battle of wits between the grim Roque and
his strongest wily rival from over the sea, and it were better that the
young aviators had tumbled from their aëroplane during the last high
flight.

But those who traveled in spirit with Billy Barry, the boy from Bangor,
Maine, U. S. A., and his plucky teammate, Henri Trouville, in France
and Belgium, can assure that it is no easy task to catch this pair
napping.

The courage tempered by that first and continuous baptism of fire was
good steel for any emergency.

Roque owned to himself that his quickfire had failed to get results.
His informant, himself just returning from a secret mission on hostile
soil, had noted the movements of the sailor suspect on the aviation
exhibit day, and also the attitude of Henri at the moment when the
message was passed. But of the message itself, the reporting agent
could have no knowledge. He was not near enough to detect a trick so
deftly done.

Roque and Ardelle had measured brains many a time and often, but
heretofore at long range, and the former had never seen the latter in
person. Had such been the case, the French agent's invasion of the
empire would have ended at Bremen, when these two masters of craft had
both been guests at the same time of the same café.

Roque's unerring judgment had convinced him after the first question
that the boys had no knowledge of the name Ardelle. Their first
profession of ignorance was too real to be mere acting. The boys took
care that the light that came to them as Roque proceeded did not shine
in the direction of the lynx-eyed questioner.

The rigid lines in the face of the secret agent relaxed. These boys,
after all, had once served him a good turn, with a skill, courage and
fidelity far beyond the ordinary, and, perhaps, he was not sorry that
he had apparently found them guiltless.

"Now, young sirs," said Roque, resuming the manner of the merchant, "I
have another little journey in store for you. I don't know for certain
that it will prove as exciting as the last jaunt we took together, when
you located a shipload of guns for me, but maybe so, maybe so.

"After we have made our excuses to the lieutenant," he continued, "we
will go over to my humble home in the city, where I have some new
clothes for you. I do not think you are warlike enough to want to
travel in any sort of uniform, especially with a simple tradesman like
myself."

It was on the tip of Billy's tongue to ask Roque why he kept up that
sort of talk with those who knew him without his mask, and when there
was no purpose to be served, but Billy concluded that he had better let
well enough alone.

A roomy carryall was in waiting at the further end of the parade
ground, toward which the merry old merchant led his young friends, with
a hand under the elbows of both. It was pardonable for the aviation
lieutenant to grin when the trio were passing, after making their
excuses.

It had not, however, occurred to Henri to smile a response. He was just
then indulging in a cold perspiration, caused by a leaping thought that
Roque might personally supervise their change of garments, and in that
curious way of his light upon the tissue billet pinned on the inside of
his (Henri's) shirt-front.

Because they had not fully understood the meaning of the dimly dashed
message, Billy had suggested that they keep it for another sitting. The
paper wad had not then turned into a torpedo.

Roque's house might have belonged to a retired gardener rather than
to the man with the iron grip who claimed it as home. The dooryard
blazed with red flowers, and the well-kept lawn was lined by earth beds
spangled with blooms in colors beyond count.

"Welcome, young sirs."

Roque waved the way into a wide hall, at the end of which yawned a
great fireplace. Bowing before them the boys saw the tallest man they
had ever met outside of a sideshow, a very giant, who wore a long gray
coat, with a good day's output for a button factory in front.

"This is my man of business, young sirs--Paul Zorn."

The "young sirs" instantly formed the opinion that Zorn would have no
trouble in cracking a cocoanut between the row of glittering teeth he
displayed when Roque so introduced him.

"We are going to put our young friends into store clothes, Paul. I hope
you will be able to properly fit them, and it will also be my care that
you do."

"Confound the man," thought Henri, "he has never since he called me
out of the machine shifted his eye long enough for me to get a hand on
that tissue, and now he's going to act as my valet. He's just full of
suspicion."

Billy, also, had been figuring some in his mind just what would break
loose if Roque should find the sailor's note in Henri's possession.
All of the powers of argument this side of the North Sea would then
avail nothing in the matter of convincing Roque that he had not been
double-crossed.

The only crumb of comfort that Billy felt he could hope for if the drop
fell was that Roque would quit his comedy acting behind the scenes
for the once--but that was scant comfort, surely, under this cloud of
anxiety.

The boys soon knew what Roque had meant by "store clothes," for
it was a regular storehouse of the styles of all nations that the
makeup magician maintained in the second floor back of his Hamburg
home--uniforms galore, the garb of the fighting man in the Old World
war, known under the folds of Britain's Union Jack, the Tricolor of
France, the black double-headed eagle of Russia, the sable Cross of the
German Empire; the attire of the dandy civilian, the sedate tradesman,
the student, the clerk, the livery of house and carriage service, and,
indeed, what not?

"A nice little collection, young sirs," observed Roque, which remark
again prompted the giant Zorn to display his mouthful of shining
molars.

"How do you think Paul would look in this outfit?"

Roque indicated on the display rack a regulation English uniform of
olive drab, with puttees, and a cap of the traditional French arms
shape, but of khaki color.

Even if the boys had been in the mood to say that Zorn would look like
the Eiffel tower in any sort of uniform, Roque gave them no time to
break in upon his humor.

"Nothing like keeping up-to-date, young sirs, in my business. It was
only a few weeks ago that this new style French soldier first appeared
in Havre. And here we can make his mate in a minute or two."

This cat and mouse play was wearing on Billy and Henri. Free of
anxiety, they might have enjoyed digging into the maze of disguises as
they would the pages of a popular detective story, but they had a play
of their own to make, and no chance yet to make it.

"Now, Paul, how will we fix up these young flyers for a bit of ground
work? Something plain, yet neat, I think, will do for the sons of
Doctor Blitz--I am Blitz to-morrow, I believe, Paul?"

Zorn simply showed his teeth. He was not expected to answer.

"Now, my bird boys, get out of those uniforms and I'll make a pair of
likely students out of you. Do you prefer Heidelberg, the School of
Arts, or the Conservatory? No matter, though, it is just a shift for a
short journey, and I guess I can make you up to pass muster."

All the time Roque was chatting principally for the amusement of
himself and Paul, his hands were busy sorting a pile of clothing and he
was ready to start a couple of young Blitzes into society in the most
finished style--from glazed cap to shiny shoes.

It was just at this moment that Billy was seized suddenly with a fit of
laughter, and his high glee was directed at Henri.

"Won't you set 'em going in that layout!" he howled.

With that he made a jump for his chum, as if to hurry the process
of transformation. The playful effort commenced at the throat and
scattered a few buttons. Henri resisted the attack, and for a second or
two held Billy in close arm lock--time enough for the assailant to get
a pin-jab in the thumb, and a wad of tissue paper in the clench of four
fingers!

Roque viewed the antics with a frown of impatience, but the assistant
of grenadier size roared his approval of the fun.

Henri was brisk enough then in taking off the old for the new, and by
the time Billy commanded attention there was no occasion for worry.

Billy had swallowed the tissue!




CHAPTER II.

A STIRRING HOLIDAY.


TO be rudely routed out of a snug nest in a feather bed at 3 o'clock
in the morning--a morning with a real chill in it--is not a desirable
experience for the average house-bred boy, and even such seasoned
campaigners as Billy Barry and Henri Trouville were inclined to grumble
when the giant Zorn yanked the covers from their downy couch and
gruffly ordered them to get up and dress, and to make haste about it.

By the pale gleam of a couple of candles, and the slight warmth from a
newly kindled fire in a white china stove, the "Blitz boys" made their
toilets of the interesting characters they were to assume.

"What time is it anyway?" yawned Henri.

"I guess I'm not good enough in higher mathematics to figure it out for
you," growled Billy, as he tussled with leather shoestrings that tied,
he said, "seven ways for Sunday."

The voice of "Dr. Blitz" sounded at the foot of the stairway, in the
lower regions of the house. There was no "young sirs" about it. The
"good merchant of Hamburg" was on vacation.

"Crawl lively there, you snails," were the words that ascended.

"Wonder what tip he is working on now?" whispered Billy.

"You will never know until you get to it." Henri had before been
impressed with the fact that Roque was not in the habit of springing
until he got on the board.

"Good morning, Dr. Blitz," was Billy's cheery greeting to the man who
was making hasty breakfast at a table drawn up before a crackling fire
in a big brick cavern. He could not have testified from side view that
it was Roque, so he took a chance on "Blitz."

Along with a gulp of coffee the imposing person addressed shot a remark
in German over his shoulder, which Henri afterward explained to Billy
was very near to profanity.

The boys edged into chairs at the table, but missed a round of muffins
through staring at the "doctor."

The merchant masquerade was wholly outclassed by this new display of
the make-up art.

Billy wanted to say "ring the night bell," but sheer admiration kept
him silent.

Whether it was the combined effects of the steaming coffee, hot
muffins, and a big black cigar that followed, or the silent tribute in
the eyes of his young guests, it was, nevertheless, a speedily noted
fact that Roque was thawing into more gracious manner.

"I suppose you know that it is only a few hours now until Christmas,
and we must find some special way to observe it."

Billy and Henri could not get the straight line on Roque's remark, but
later realized that the holiday was of the like they had never before
passed.

With a cutting wind from off the icy flow of the mighty river Elbe in
their faces, the boys followed their leader to the docks, where they
boarded a small craft, evidently built for speed, which had steam up
and manned for instant start.

The captain was the same who commanded the deck when the boys had
accompanied Roque on a previous exciting excursion. This official,
standing at attention, stiff as a ramrod, gave no visible mark of
recognition as the passengers boarded the boat, but Billy could have
sworn that he saw something like a twinkle in the captain's right eye
when they passed the gangplank.

"No use asking where we are bound for," lamented Henri.

"Not a bit of use," agreed Billy.

They were out of earshot of Roque, whose tall form, in rusty black, was
outlined in the dawnlight near the wheel of the churning steamer.

The first intimation of what was to be their next landing place came in
the word "Cuxhaven," passed by one sailor to another. The talk was in
rapid German, but Henri caught the drift of the conversation without
difficulty.

"By George," he whispered to his chum, "Cuxhaven is the place mentioned
in Anglin's message."

"You mean Ardelle's message," corrected Billy.

"That's right," chuckled Henri. "I forgot that Anglin had become the
big noise. Yes, it's the very place," he continued, "and it's a great
naval base."

"It's a safe bet that Roque never hits a trail that isn't warm. Take
it from me," and Billy was in great earnest when he said it, "there is
going to be something doing."

Billy's prediction chanced, in this instance, to be more accurate than
are some of the forecasts made by professionals.

It was in a dense fog that Christmas eve when the little steamer ceased
chugging in the wide mouth of the Elbe, and the harbor lights burned
blue. The captain condemned the weather in no uncertain terms, but
Roque seemingly had no care for aught but his thoughts, as he leaned
against the rail, with moody gaze fixed upon the anchored ships and the
dim lines of the city beyond.

As he had shaped, not long ago, the famous raid of the German fleet
upon English seaports, Roque did not underestimate the ability of his
great rival, Ardelle, to open the way for a counter attack. Ardelle was
known by the secret service to be on this very soil--and, surely, for
some big purpose. Minnows were not sent to stir up a pool of this size.

"But they'll find no sleepy towns to blow up here," said Roque to
himself.

He was all for precaution, however, and his intuition was nothing short
of marvelous.

When "Dr. Blitz" and his "sons" went ashore it was the foggiest kind of
a Christmas morning.

A stalwart marine attempted to put the doctor through the question
paces, but the real Roque whispered a fierce something into the ear of
the would-be questioner that set the latter back-tracking in a jiffy.

It was a curious and remarkable fact, but true, that an hour after the
eminent secret agent and his young charges had landed in Cuxhaven,
Billy's prediction, "that wherever Roque is there's something doing,"
was verified. Every submarine cable connecting the fortresses of this
coast sounded alarm, particularly high-keyed the frantic signal from
Helgoland, the fortress island, thirty-nine miles away.

Roque dropped his doctor character like a hot potato when he learned
the import of the flashes. He tossed his traveling case of surgical
instruments into the first open doorway he passed, and the boys were
compelled to run to keep up with his long stride.

Bombs were falling from aloft, exploding among the shipping behind
them, while in front one of the projectiles crashed upon a huge gas
tank.

"The nerve of the devil mapped this out!"

The bitter emphasis of Roque indicated that he laid the blame of this
unexpected invasion upon one head--that of Ardelle.

In the meantime, the fog-ridden atmosphere was riven by blazes of
powder from the shore guns, trained upward, and the air squadron,
Zeppelins and naval seaplanes, were leaping skyward to meet their kind
in aërial battle.

Roque charged madly into the air station, dragging the boys after him.

A seaplane was balanced on the polished ways for the sweeping plunge.

"In the name of the Emperor!" he shouted, shouldering aside the men
holding the poised craft. The same fierce whisper in the ear of the
aviation lieutenant had effect identical with that upon the marine at
the docks.

"Get to your places, you moonfaces"--this stern command hurled at the
boys. Henri bounced into the motor section, Billy settled behind the
rudder wheel, and Roque swung himself into the bow seat.

The long hull was launched with the snap of training, and with motors
humming left the water without a wrench from its skimming start.

The Boy Aviators, certified masters of the air, were at their trade.

They had need of all their skill and daring that day!

"Set your course northwest," loudly ordered Roque. "Hit for Helgoland
like a bolt."

"Look out that you don't hit something on the way!" shouted Henri from
the rear.

The last warning was timely, if Billy had need of warning at all. There
was peril in the foggy stretches.

The upper regions were literally lined with aircraft. No less than
seven naval seaplanes had traveled in advance of the British warship
invasion of the German bay. Having dropped all the bombs they could
through the mist, they were in full return flight to the convoying
vessels. Zeppelins and hostile seaplanes zigzagged on their trail, and
other dirigibles and fighting craft menaced their retreat still further
on.

Billy guided the seaplane he was driving to the higher strata in order
to escape mix-up with the contending airships, but on the thirtieth
mile recorded, Roque, who had constantly demanded distance figures,
ordered a lower flight, and, the fog clearing, the flyers could plainly
see on the waves far below the floating warcraft of the invaders--light
cruisers, destroyers and submarines. The Germans were combating this
array with aircraft and submarines, but so great was Roque's impatience
to reach the fortified island that the motors were put by Henri to the
limit of speed, and so that part of the conflict is not in the record
of the Aëroplane Scouts.

Just off Helgoland, though, the boys had the shock of noting the
crumpling of one of the British seaplanes and the end of a brave airman.

"There's no escape when death stalks you up here," sighed Billy.

"Ware away, boy," called Roque, when the seaplane hovered over
Helgoland, "wait until they see the color of the bottom of the machine
or we will look like a sieve before we light."

Billy "wared away," and with motors at half speed, the seaplane circled
over the supposed most impregnable stronghold in the world, awaiting
some signal of recognition from the fortress.

It was finally given, and Roque directed immediate descent.

On the ground once more, Billy and Henri relapsed into their dutiful
service as "sons" and rear guards of the renowned "Dr. Blitz." The
glazed caps had gone the way of the winds, but, as Billy put it, "we
are still dressed up to beat the band."

The boys noticed that, barring a few skilled workmen and engineers,
they were the only civilians in the streets that evening. They did not
count Roque, for he might turn out to be a general, if occasion served.

The latter had a busy hour with the garrison officers, while the boys
had an idle one, with about as much activity as is allowed a hobbled
horse. It was evident that "Dr. Blitz" held this island as a holy of
holies, secret even to his "sons."

"It beats me," observed Billy, edging away as far as possible from the
guard stationed to keep them out of mischief, "how those Britishers
ever got by this place."

"The bigger question," asserted Henri, "is, if they got by, how in the
world did they ever get back?"

"That's what Roque is evidently trying to find out," intimated Billy.

The boys, while puzzling over the problem of "get by and get back,"
were looking at the huge fortress so tremendously fortified and noting
everywhere an uninterrupted view of the sea.

They also surmised that an alert garrison was ever carefully watching
the waters, day after day, night after night, hour after hour, in order
not to be surprised by the powerful enemy.

"I guess the fog helped some," was the conclusion finally advanced by
Billy.

"And Ardelle somewhere behind the curtain," suggested Henri.

"Oh, go 'way, man; Roque has given you the Ardelle fever."

Billy just then caught sight of Roque bearing down upon them under full
stride.

"Speak of the dickens," he exclaimed, "here he comes now."

The shadows of evening continued to gather, and here and there on the
island lights showed like glowworms. Roque shook hands with his officer
companions. He evidently contemplated leaving in the same impetuous way
that he came, but evidently not by the seaplane route.

A little steam launch tugged at its holding rope, in readiness to dash
away into the misty deep. Two men muffled to the throat waited the
order. Roque, with never a word to the boys, directed them by gestures
to get aboard, quickly following. The launch cut through the now pitchy
darkness of the Helgoland waters. With the island lights no longer
visible, there could only be seen the lantern in front of the little
boat, and it was a dangerous speed to be making, when the helmsman had
scant view of hardly a yard ahead.

But the man at the wheel was in familiar element, to him, and the
scudding vessel never came to drift movement until a glimmering signal
guided to the landing place, the name of which would have meant nothing
to the boys if they had had the care to inquire.

This was Christmas night in the Bight of Helgoland.




CHAPTER III.

A THRILLING MOMENT.


UNDER oak rafters, festooned with dried herbs, and toasting their feet
at the cheery blaze of an open, roaring fire, the boys regained the
Christmas spirit that had been sorely subdued in the previous dismal
hour in the wave-tossed launch.

The house that had thrown open a hospitable door at the bidding of
Roque overlooked the bay, and its solid walls had resisted the storms
of a half-century. Mine host, Spitznagle, had he been dressed for the
part, would have come very near to the Santa Claus idea, and even as he
was, some of the idea hung about him in a radiant circle.

He could not, though, have possibly trimmed a tree in manner more
satisfactory than he decorated the big, square table in the center of
the wooden-walled dining-room, within easy distance of that first-class
fire. Sizzling sausages, small mountains of crullers, fragrant coffee,
mulled cider, and such like in quality and quantity, indicated a royal
spread.

Roque, who had been prowling around somewhere outside for a time,
suddenly preceded a gust of sleety wind into the cozy interior.

The Christmas spirit had apparently conjured up a bit of a kindly
spell for him, as the iron man fitted into the scene with far less
friction than the boys had anticipated, considering the mood of this
driving force during the trying day.

"Snug haven, this, eh?" jovially queried the late arrival, as he spread
a pair of sinewy hands over the inviting fire. "You're spoiling these
youngsters, Spitz," was Roque's side remark to the blooming boniface,
at the moment stirring some savory stew in a glistening copper pot.
Mine Host waved a three-foot spoon in mock protest against the playful
accusation.

"Nothing like that at all, my dear man," he declared in big bass tone.
"I will not spoil but will cure these children of their hunger."

"Draw up, my hearties," urged Roque, setting example by dragging an oak
bench alongside of the bountifully laden table. Billy and Henri jumped
at the bidding.

"Where are the men that brought us over?" asked Billy, presuming upon
the fact that Roque was in one of the rare periods out of his shell.

"Back, I hope, where they came from," briefly replied Roque. "Those
fellows are hardy stock," he added, "and can see in the dark. Don't
worry about them."

"Cuxhaven is some aircraft place, isn't it?" Henri put this wedge in
the conversation.

"Perhaps it is," acknowledged the secret agent, "and" (grimly) "it may
soon return the upper-story visit just paid with a cloudful of warcraft
that will start a general hunt for cover."

"Had you ridden often in airships before to-day, Mr. Roque?" inquired
Billy.

Spitznagle muffled a chuckle by a slight fit of coughing when he heard
the question, and muttered something to himself like "donner vetter!"

Roque turned a quick eye upon the fat offender, and then gave Billy a
smiling look-over before he made response.

"I confess, young man, that I have enjoyed some lofty travel before I
met you, but I am willing to admit that I could not teach you and that
partner of yours many new tricks in flying the heavier than air kind of
machines."

"How about the Zeppelins?" cried Spitznagle, who could no longer
suppress a desire to show his knowledge of Roque's prowess as an airman.

"Hold your peace, Arnold," advised the secret agent, shaking his finger
at the eager champion, "my business compels me to learn a little of
everything, and it's all in a day's work, anyway."

The boys were satisfied that Roque's renown had not all of it been won
on the ground. Spitznagle would have made a good witness to that effect
if he had been permitted to speak.

While the tall clock in the turn of the winding staircase leading to
the upper floor of the old house was whanging the twelve strokes of
midnight, Roque and Spitznagle pledged the fatherland with uplifted
goblets, and Billy and Henri offered a silent toast to the assured soft
beds upstairs.

When the early morning brought no disturbance of their inclination for
a little longer time to press the pillows, the boys sleepily guessed
that Roque, for once, was not in a hurry to dash into new territory.
As the sun kept climbing, and still no summons from below, curiosity
overruled napping, and the young aviators decided to investigate the
cause of this unusual consideration of their comfort.

Halfway down the stairway their ears convinced them that the place
was not deserted, for a spirited conversation in the language of the
country was in progress, accompanied by a clatter of dishes, and the
ever present cooking odor of sausage assailed their noses.

Besides Spitznagle, shrouded to the rib-line with his flowing apron,
were three very short men and an extremely long one. The latter proved
to be no other than the giant Zorn. Roque was nowhere to be seen.

The heavy host noisily hailed the late comers:

"Good morning, sleepyheads, and all this fine food waiting for you,
too."

Zorn gave his best wide-mouthed grin, and then went on talking, in
lower tones, however, to his short companions.

Billy and Henri made a substantial breakfast, and in doing so, hardly
felt the need of the constant urging of the boss cook.

They could not imagine what had become of Roque, and as nobody
volunteered to tell them, they concluded not to ask any questions.

The boys observed that one of the short men, with a large head wholly
out of proportion with his stocky body, commanded much deference from
the rest of the party.

Henri learned from the drift of the conversation that this determined
looking individual was Capt. Groat of Friedrichshaven, the great center
of Zeppelin factories, and while the captain was not in uniform he had
the manner of rank.

Billy was quietly advised by his chum what the talk was about, and
wagered that the two strangers were airmen.

"When these fellows commence to flock together on this coast," he
asserted, "you can figure on what Roque meant when he fixed a comeback
to get even for that flying raid yesterday on Cuxhaven."

The boys had withdrawn to the fireplace, and had an opportunity to
exchange comments and conclusions between themselves.

"I'd like to take a whirl myself in one of those Zeppelins," was the
wish expressed by Henri.

"Our flying education has been sadly neglected in that respect,"
admitted Billy, "but, you know, these dirigibles are among the things
made only in Germany, and we're just over, so to speak."

As the morning wore away, Zorn made some remark to Capt. Groat that had
attracted the latter's attention to the boys lounging at the fireplace.
The captain arose from the table and approached Billy and Henri with
outstretched hand.

"You speak the German?" With the question he bestowed a strenuous grip
upon each of the boys.

Henri nodded, and Billy confessed by blank look that he did not know
the language.

"It is easy, the English," politely assured the captain, "and we will
talk it together."

Billy brightened at this. He was not fond of hearing through an
interpreter.

"I hear you are the great aviators, and for so young it is wonderful."

"Thank you, sir," was Henri's modest acknowledgment.

"It is with the Zeppelin I navigate," advised the captain. "You know it
not?"

"Not much," put in Billy, "though we once dangled on the anchor of one,
and another time I fell with a monoplane right across the back of one
of your dirigibles."

"Yes," remarked Henri, "and if it hadn't been for that, there wouldn't
have been any Billy alive to tell about it."

The captain showed a disposition to continue his talk during the
afternoon with the boys, but a new arrival of evident importance
interrupted. This addition to the party was a much older man than the
rest, wore a military cloak, and his long, gray mustache curled at the
ends in close touch with his ears. As he stood at the end of the big
table, now cleared of its cloth, and rested a hand, enveloped in a
gauntlet, upon the shining surface, everybody in the room saluted. Over
the shoulder of this distinguished guest the boys saw the face of Roque.

As if by signal, further increased by the hasty entrance of three
additional numbers, the attending company ranged by equal division on
each side of the table, and all followed the directing movement of the
man at the head of the board in seating themselves.

Billy and Henri were the only bystanders, for though Spitznagle had not
ventured to flop down upon a bench at the table, he perched himself on
a high stool, completely blocking the door leading into the pantry.

One of the short men who had first appeared with Capt. Groat produced
a capacious wallet, and laid out in orderly array a number of neatly
folded papers which had been contained in the leather.

"This is the navigator detailed to determine air currents, sir,"
explained Roque to the chief figure, at whose right elbow the secret
agent was stationed.

The man in the cloak fixed his gaze on the expert with the notes. The
latter accepted this as permission to speak, and read in precise manner
the results of close observation during a recent aërial expedition of
Zeppelins, escorted by armed German biplanes, in the vicinity of Dover
straits.

Henri's quick ear and thorough knowledge of the Teuton tongue put him
in line of complete understanding of the report, and that it seemed
preliminary to a proposed general raid of aircraft on territory with
which he was well acquainted.

Billy's only satisfaction was in watching his chum's change of
expression as the news sifted through the latter's mind. He could see
that there was "something doing."

So intently interested was the gathering at the table in the reading,
that the very existence of the youthful outsiders seemed to be
forgotten.

"Good; excellent!" commented the chief.

"It's a game with double trumps." Roque held the affair at Cuxhaven as
a choking memory.

"There'll be quite a fall of hot shot, I promise you, if we get started
right." This was the prediction of Captain Groat.

His lieutenants from Friedrichshaven nodded their approval.

In anticipation of a telling counterstroke by their air squadron, the
plan makers at the table puffed up clouds of smoke from pipes and
cigars, freely distributed by the happy Spitznagle when the lengthy
discussion officially ended. In the added hours, when stone mugs were
passing among the thirsty, night had fallen outside, and the benches
were turned to the glowing fire.

While Spitznagle was touching the tips of numerous candles with the
tiny flame from a paper spiral, the empty mugs were being removed by an
oddly dressed fellow, who shuffled around in carpet slippers like he
was tormented with a thousand pangs of rheumatism.

The boys had boosted themselves to good lookout points on the wide
window ledges, behind the lively circle around the fire.

The leather wallet and the survey notes of the expert air traveler lay
separate and apart on the table, just as they had when the reading
concluded.

Billy was idly watching the halting action of the queer servitor, when,
to the great astonishment of the watcher, the apparent cripple, with
rapid hand movement, under cover of the wiping cloth he carried, deftly
lifted and concealed the papers somewhere in the scarecrow garments he
wore.

It was a tense moment. The word that would have turned things upside
down in that room trembled on Billy's lips. But one of those remarkable
instances of mental telegraphy checked the utterance. The man who
had stolen the papers felt that his action had been detected from an
unexpected quarter, and his eyes lifted to the very point of danger.
There was an appeal in the look--and something else, a flash of
recognition that compelled a response. They were the smiling eyes of
Anglin--or, as Roque would have it, Ardelle.

Billy, tongued-tied, saw the bent figure slowly shuffle toward the
kitchen. He inwardly trembled at the thought of the stocky airman
suddenly turning from the fireplace to seek his precious reports. He
added another little shake in advance of the turmoil that was bound
to be raised, anyhow, no matter how soon or how late the loss should
be discovered. But the consolation of delayed discovery would be that
Anglin had a chance to save his neck.

"What's the matter with you, pal?" Henri had just noticed that Billy
was off color and wide-eyed as a trapped rabbit.

Billy, for caution, laid a finger on his lips. "I've seen a ghost," he
whispered.

With a glance of apprehension at the group circling the fireplace,
Billy leaned against the shoulder of his chum and with underbreath
speed told of the presence of Anglin and the taking of the papers.

Henri was thrilled by the exciting story poured into his ear, and
immediately took on his share of anxiety as to the outcome of Anglin's
daring action.

Bursts of laughter resounded at the fireplace. The company was then
applauding some humorous tale volunteered by Zorn, who had risen like
a tower to impress the point of his story.

"Gee," murmured Billy, "will they never quit?"

"Don't fret," advised Henri, "the blow will fall in due time."

It did fall a few minutes later.

The main mover of the meeting was saying: "Gentlemen, it is nearing a
new day, and there is great achievement before us. We go to prepare for
it."

Benches were pushed back to clear the way, and this scraping sound
had hardly ceased when the short airman, who had made the interesting
report, hurried to the table for his valuable records.

The boys leaned forward in breathless suspense.




CHAPTER IV.

THE STOLEN PAPERS.


"MY papers! The report! Has anybody seen them?"

The owner of the wallet shook it vigorously over the table, to
assure himself that he had not replaced the records there, and then
quickstepped the whole length and around the board, lowering his head
again and again beneath the polished surface to see if the documents he
was excitedly seeking could have possibly fallen on the floor.

"What's that?" cried Roque, starting forward. "You've lost the papers,
you say?"

"I didn't lose them," almost shouted the airman, "they were left on the
table, and if they're gone, they've been stolen."

"Hey, my friend," remonstrated Spitznagle, "we have no thieves in this
house, and no enemies to the cause."

"This is no time to bandy words," roared Roque, "shut and bar the
doors"--this last command directed at Zorn. The giant jumped at the
bidding and sent the bolts rattling into their sockets.

The savage energy of Roque ruled all to silence. Even the power under
the cloak refrained from advising.

The secret agent dismissed suspicion as to the active participants in
the conference, and as to the loyalty of Spitznagle he had not the
slightest doubt. The trial horses must needs be two pale-faced boys
backed up against a window-sill.

Roque, with his hands deep in his pockets, a habit he had when stalking
a suspect, walked around the foot of the table and stood directly in
front of the pair, fixing on them that gimlet gaze he used to terrorize.

Billy and Henri, when at bay, were the most keenly alive; their nerve
always served them most in the supreme test.

They faced their inquisitor without an outward tremor; their previous
anxiety was known only to themselves, and now admirably concealed.

Roque realized that he had no fluttering birds in his hands, and also
was aware that a search of their persons was only required to acquit
or convict these youngsters of the actual theft. He knew that they had
not left the room, though why he had not long ago sent them upstairs to
bed was a slip of mind he could not account for. But it had occurred
to Roque that the boys had been in a position to see the table all
the time since the company adjourned to the fire, and whatever had
happened in regard to the papers they, if not the light-fingered chaps
themselves, must have witnessed the perpetration of the steal. So he
changed his tactics.

"Now, boys," he began with insinuating address, "there is a very ugly
situation here, and as I have always heretofore found you dependable,
cannot I now depend upon you to help me clear this up?"

Henri shook his head, in denial for both. "Search us," he said.

Roque, whose remarkable judgment of human nature has before been noted,
felt in an instant that the suggested search would develop nothing.

"Who took the papers then?" he fiercely demanded.

"We were not on guard duty." Billy was inclined to resent this
bullying, and showed it by his answer.

"Strip them," urged the short airman, who thought he, as the loser,
ought to have a word in the controversy.

Roque waved the man away, and then abruptly moved to where Spitznagle
was sitting, a picture of despair.

"Who was in the house to-night besides those now present?" was the
question fired at Mine Host.

"Nobody but Conrad," assured Spitznagle.

"Who the devil is Conrad?" Roque fairly jumped at this information.

"Why, a poor crippled fellow, as queer in the head as he was in the
legs, that I had helping in the kitchen. He lost his job as cook on the
coast line steamer _Druid_ on account of rheumatism, and they sent him
up here to me."

"'They sent him up,' did 'they?' And now when did 'they' send him up?"

"About a week ago. But what's all this about Conrad you're asking,
Roque? I'll have him in, and you can judge if he is worth a moment's
notice in this kind of affair." Spitznagle started for the kitchen
door, Roque at his heels.

"Conrad, Conrad," called Spitznagle.

"Conrad" had flown, leaving nothing behind him but his rheumatism and a
dingy apron.

"Yell till you're hoarse, you fathead," raged Roque, "and the cows will
come home from nowhere before you get an answer."

While Spitznagle was staring into vacancy, Roque stormed back into the
dining-room and announced:

"We've been the dupes of that spy Ardelle. Nobody but he could have
gotten away with a venture like this. But" (gritting his teeth), "I'll
beat him yet. I say, Vollmer" (turning to the aërial recorder now
minus his records), "you have the whole thing in mind and we'll strike
while the iron is hot. We may outride the warning, for he can't get it
flashed from this coast."

The man in the cloak came to the front on this proposition. "The word
is 'immediate,'" he proclaimed.

A speedy departure was in order, and Roque crooked a finger at the
young aviators, bidding them follow.

"You are going to be mighty useful, my flying friends," he said, "and
you'd better be." There was grim emphasis in these last words.

At noon the next day the boys were again tramping around after Roque
in Cuxhaven. The character of "Dr. Blitz" was no longer in the play.
Roque was trimly set up as an aviation lieutenant, and it was really
wonderful how easily he merged into each part he assumed. "Students" no
longer, Billy and Henri were happy in resuming their flying clothes.

"Best becomes our style of beauty," as Billy would have it.

There seemed to be some unforeseen reason for delay, as the aërial
expedition did not start forthwith, as intended. Indeed, it did not
start from Cuxhaven at all. It might have been that Ardelle's theft of
the guide records had put a spoke in the German wheel, but as to that
the boys could only hazard a guess.

It was on the twentieth day after the adventure in the house of
Spitznagle that the young aviators again had the opportunity of
operating a seaplane with Roque as directing passenger, and the
uninterrupted flight brought them to the island of Amesland, for
though Cuxhaven was counted as the airship base, it evidently was the
intent to project the return attack on the English coast from the
out-to-sea point before named.

What an array of the warcraft of the "upper deep"--the great
dirigibles, seaplanes, destroyer, artillery spotter and scout
aëroplanes. The boys were in their element. Even Roque had a smile for
their enthusiasm. It was not the war spirit that animated Billy and
Henri--they reveled in the show as airmen delighted with the life.

In this camp were none but the suicidally brave type of fighters,
and it was only that kind fit to essay the trackless line of three
hundred miles over the sea. From what the boys, or, rather one of them,
Henri, could learn from the camp talk, a pair of the latest Zeppelin
dirigibles were to participate, but the main movers of this attack
were evidently to be airships of the small, non-rigid Parseval build,
for bomb work. The truth of the matter was, the young aviators, at
the order of Roque, were so taken up with the tuning of a seaplane
just before the fleet went aloft that they could not have listed the
starters with any degree of accuracy.

They only knew positively that they were going aloft, and their own
machine would require their individual attention. About 8:30 that night
the glare of a powerful searchlight from one of the German airships
directed its rays over the heart of the English city of Yarmouth. Two
bombs dropped almost simultaneously.

The boys saw the city below suddenly plunged into darkness. Five more
bombs were hurled from the sky. The fleet then swiftly moved northeast,
and more bombs crashed into the town of Kings Lynn. Roque had assumed
no active part as a leader in the deadly maneuvers--his was a thinking
assignment. It was midnight when the fleet turned eastward and fled
back across the North Sea.

"It might have been London," muttered the secret agent, "if the game
could have been played without a break."

Preparations to repel just such an invasion had been made in the great
city.

Ardelle must have gotten his warning across, but the coast towns failed
to heed it.

The Roque machine kept its speed when the balance of the fleet checked
flight at Amesland. The secret agent was bound for Cuxhaven, doubtless
to plan another tiger spring at the foe. He was all for air campaigning
these days.

"You will witness the sight of your lives, you young cyclones, before
last night's mist of the North Sea dries in your hair."

This significant remark on Cuxhaven docks set the boys in the highest
state of expectancy. It was seldom that Roque billed anything ahead of
time, and surely something extraordinary must be in the wind.

Three days later, from a dizzy height, they witnessed a sky battle
without parallel in military annals, and which dimmed the memory of any
of their previous remarkable experiences in the war zone.

The French coast town of Dunkirk, to which the boys had on a happy day
gone by been delivered by submarine and taken away in a seaplane, was
the ground center of this spectacular conquest of the air--the first of
its kind in the history of the world.

Twenty hours earlier a fleet of British seaplanes had bombarded the
Belgian port of Zeebrugge, held by the Germans, news of which had soon
after reached the mystery man, Roque, by way of one of the innumerable
channels of communication with which he kept himself constantly in
touch.

The German bird craft suddenly appeared over Dunkirk like a flock of
gigantic sea gulls.

Explosive missiles fell as fiery hail upon the town. The tocsin sounded
in the high tower of Dunkirk church, and the blue and white flag of the
town was run up.

The roar of the fort guns, firing shrapnel, was heard, and all around
the German fliers white puffs were bursting, as the pilots guided their
machines in low-swooping spirals.

In compliance with the snappy commands of Roque, Billy circled the
seaplane to every point of observation vantage, while the secret agent
viewed the action of the armored Aviatik biplanes, dashing here and
there with the sun glinting on their steel sides.

"Look there!" shouted Henri, rising and clutching a stay to preserve
his balance. The air was clear, and the scene was open even to the
naked eye.

Billy, at the wheel, risked a glance sideways.

A squadron of British aviators, encamped on the outskirts of Dunkirk,
had taken the air to engage the raiders.

One speedy biplane darted straight toward the German craft. Henri saw
the aviator clutch the levers of his machine in one hand and with the
other unsling a rifle, beginning fire at a German birdman below him.

A half dozen armored aëroplanes of the raiding force swarmed in upon
the daring Briton. His machine was peppered with lead, and it was
apparent that the man had been wounded as he dipped toward the earth to
evade the encircling Germans.

Other English aviators swept into the whirling combat, and to the
rescue of their wounded leader. The raiders turned toward the north,
now being shrapnelled by anti-aircraft guns stationed along the coast.

Roque pointed upwards, signalling for rapid ascent, and at six
thousand feet the seaplane, with tremendous burst of speed, soon
overhauled and outdistanced the slower warcraft, making a wide detour
over the sea, thus avoiding the volleys of rifle shots from the Allies'
infantry near Nieuport.

Roque, looking at his watch, turned to Billy, just behind him,
remarking:

"That much in fifty minutes is not often recorded--of these things they
shall sing on the Rhine."

In Bremen the boys paid grateful tribute to rest after the strain and
stress to which they had been put by their relentless taskmaster.

"I feel," said Billy, "like the hump between my shoulders is going to
be permanent, and I couldn't keep my elbows down to save my soul."

"If I could only get the whirr out of my ears, I'd be satisfied," was
Henri's complaint.

It was not long, however, before the boys found relief from the kinks
in their backs, and were ready and eager for the next move in their
adventurous careers.

Just around the corner from their hotel was the very café where they
had the thrill of seeing Anglin's face in the mirror while they were
dining there with Roque.

"Wouldn't it be funny if Anglin were to bob up again while we are here?"

"I think, Billy, that it would be a tragedy if Roque had any inkling of
it."

"Don't you hold the thought for a moment, Henri, that you could catch
the Calais weasel asleep. Oh, I say, there's a concert on downstairs,"
quickly concluded Billy, as the notes of violin and piano were wafted
above. "Let's hunt the music."

A high tenor voice was merging into the accompaniment when the boys
reached the floor below, and they saw that the singer was one of the
curly-lock type, and in evening attire.

What of the eyes, though, that gleamed upon the Aëroplane Scouts as
they stood in the doorway--the artistic make-up could fool them, but
there was no mistaking the smiling orbs under the blackened eyebrows.

Fox tracks were mixing again!




CHAPTER V.

WHEN THE LIGHTS WENT OUT.


THE vocal efforts of this new favorite had called forth round after
round of applause, for good music never went amiss in Teuton territory.

Among the vigorous hand-clappers the boys noted a well-groomed man,
apparently about forty, wearing an affable manner and the best clothes
that the continent can produce.

Henri nudged Billy. "Size up Roque, won't you, please, and isn't he a
dandy?"

Billy was first inclined to doubt the identity of their taskmaster, who
a couple of hours ago was a far cry from being in the glass of fashion.
Never before had the boys seen him in that sort of rig.

"You're dead right, Henri, it is the old scout. He's a corker, sure!"

This note of admiration had scarcely sounded when Roque was joined by a
slender, wiry individual, also set up as a swell, with a shock of sandy
hair, and sporting a monocle.

The fellow with the quizzing glass had apparently moved to get a better
view of the singer, as well as to get in touch with the secret agent.

"Wonder if that's the man who spotted Anglin on the parade ground at
Hamburg?"

"Don't let your imagination run away with you, Henri," advised Billy,
who in speaking was careful not to indicate that his attitude was
anything but careless.

The sandy-haired man was taking the same precaution, but Henri, nursing
the idea that would not down, was more and more impressed with the
belief that the elegant figure was seeking the measure and not the
music of the warbler at the other end of the room.

If the singer had sized up the situation, it had not affected his
rendering a bit of light opera that was just then exciting an encore.
There was nothing at all the matter with his German or with his voice.

Nobody apparently was more delighted than Roque, and he appeared to be
expressing his opinion to the wiry listener beside him.

The latter bowed politely and then sauntered toward the revolving door
leading into the lounging section of the hotel, fingering a cigar as he
proceeded.

Henri edged around nearer to the piano, the player of which was
completing the program with a national air, the melody of many voices
aiding the performance.

Billy had hardly realized the desertion of his chum when he saw that
Roque had changed his position, and was standing nearest the door
leading to the street. The secret agent shifted something from his hip
to the sidepocket of his coat, and Billy caught the glitter of that
something in the swift movement. The boy guessed then that there was
trouble brewing.

In the meantime, Henri, in an innocent sort of way, pushed still closer
to the pianist, who was hitting the high notes in fine style.

As he passed within a foot of the singer, now idly posing, with an
elbow on the piano top, he, without turning his head, joined in the
triumphant chorus, but changed two words at the climax, and "beat it"
reached Anglin's ear.

The French sleuth never moved a muscle, and it was as if the warning
had been passed to a man stone deaf.

Anyone posted, however, would have known that within an arm's length of
Anglin was a wall switch which controlled the electric lights by which
the room was so brilliantly illuminated.

Billy had just had the experience of being rather rudely thrust aside
by a couple of burly troopers, who seemed inspired to get as quickly as
possible into the very center of the select circle.

"Get him!"

As this command rang out the astonished pleasure seekers started a
panic, as if an alarm of fire had sounded. There was a rush for every
doorway, but every way of departure was blocked by stalwart guardsmen.

Billy was not among those who tried to break through the doors--he was
dodging among the charging force sent in by the loud orders to "get
him."

Click! The room was suddenly shrouded in darkness, penetrated a little
distance only by the lights beyond the entrance of the lounging room
section.

The pursuing force, working from several directions, ran into one
another's arms. The pianist, familiar with the place, leaped for the
electric switch, and turned on the flood of light.

Everybody was present but the singer!

Henri had a perch on the keyboard of the piano, which he had sought to
save a mad tramping on his feet.

"Set you to catch a weasel," sneered Roque, as the sandy-haired man
stood staring at the shattered casement of the tall window overlooking
an inner court of the hotel.

"He can't get clear away," retorted the sandy one.

"Stop him then," challenged Roque. "Don't stand there like a stoughton
bottle."

The pursuers scoured the building from bottom to top, and every street
and alley roundabout, but it was a case of looking for a needle in a
haystack.

Roque was in a black mood. Once more baffled by his cunning chief
adversary, the only one he acknowledged in his own class, and on his
own stamping ground--it was a bitter dose for the master craftsman.

Did he remember how he himself had spread a web over Britain, woven so
finely that even Scotland Yard could not see it? Yet he rebelled at the
like cut of a diamond.

"Stir your stumps," was his peremptory address to the boys, and they
trotted to catch his long stride out of the hotel.

The sidewalks on both sides of the street were crowded with curious
onlookers, attracted by the reported doings inside.

Roque bucked the line like a football star, and Billy and Henri
followed in the cleared space without special exertion.

"He doesn't care whom he pushes," observed Billy, as he listened to
angry protests along the line of travel.

Both of the boys were eager to talk over the latest disappearing act of
that wonderful Anglin, but not so anxious as to take chances with Roque
in earshot.

The secret agent turned into a silent side street, and stopped before a
heavily grated door in the gloomy front of a solid stone building that
was a skyscraper in height. Reaching through the grating, he evidently
opened way of communication with the interior, for in a moment or two a
glimmer of light splintered through the barred entrance, the ponderous
lock creaked, and the door swung back on its massive hinges. A skull
cap and a gray beard showed behind the lamp shining in the doorway.
Roque pushed the boys ahead of him, and their closing in was marked by
a clang behind them.

They followed their guide through a long corridor and into a modern
high-power elevator, that shot noiselessly upwards. It was a circular
room into which they stepped, the very tip of a tower, and a wireless
telegraph apparatus was there in operation.

"How is it working?" promptly questioned Roque of an operator who was
off his turn, and relieved of his headgear.

The man jumped to his feet, all attention, and replied: "There's been
hardly a break for an hour, sir."

Here was one of the hidden intelligence stations that accounted in
part for Roque's ability to get searching and quick information. That
he should initiate the boys into his particular secret service methods
indicated a determination that they should never get away from him.

As Billy said to Henri at a chance moment, "He thinks we are booked
for a life job as his air chauffeurs."

They were not aware as yet that in the extensive grounds, housed at the
water's edge, was the seaplane in which they had recently traveled so
far, and in addition a big biplane and two monoplanes were in hangars
ready for service. Also the most speedy of steam launches rested at the
private wharf.

Roque was a recognized genius, like every cog in the German wheel,
absolutely thorough in his methods, and the means placed at his
disposal were practically limitless.

Billy and Henri had climbed into the steep embrasure of a tower window
and were enjoying the magnificent view spread out before them.

"How about my imagination now?" Henri was recalling exciting incidents
in the hotel. "Didn't I get the figure of the sandy man as a spotter?"

"I think you did," admitted Billy. "But," he continued, "I didn't take
much stock in the idea until I saw the revolver in Roque's hand. Then I
knew that the fat was in the fire."

"I gave Anglin the cue to beat it, and I did the trick by breaking into
that Rhine song," exclaimed Henri. "Yet he never made a move until the
yell of 'get him,' and I thought the jig was up, sure. He's the coolest
hand in the business, that fellow."

"Some of these days, maybe, he'll fall a little short in one of those
getaways, and that will mean a tumble into six feet of earth."

"Not he," stoutly maintained Henri, "he's the regular man with a
charmed life. Say, I can't help laughing even now when I think of
Spitznagle calling 'Conrad,' and the expression on Roque's face."

Billy gave Henri a kick on the foot. Roque was approaching with a sheaf
of telegraph messages in his hand.

"What are you boys jabbering about? I want you to go down to the wharf
with Albert and get the seaplane in trim. I'll join you in half an
hour."

Albert, a strapping youth, with the breezy way of a sailor, guided the
boys across the grounds to the hangar, and watched with interest the
making ready of the airship.

"That's not my kind of a boat," he briskly stated, "but I'll be bound
if this kind of craft didn't give us submarine workers a Christmas
surprise. Ever travel in a submarine?"

"We had a ride in one that we will never forget," replied Henri, as he
applied the oil can to the big motors.

Billy, busy with the steering gear, was not expected to answer, as he
did not understand the question.

"It is all a question of ups and downs, anyhow," went on Albert, "bombs
from above and torpedoes from below."

This trade discussion ended with the arrival of Roque, who had severed
himself from style and was again in aviation attire.

"Now, my carrier pigeons, you are in for a homing flight, that is,
Hamburg; and it may be some time before you again get a breath of this
port."

With this assurance the seaplane was launched and took the airline for
Hamburg, leaving Albert to his own devices.

The travelers soon had sight of Zorn's ever-ready grin at the home of
"the well-known tradesman."

"We've been through a lot since we were last hauled out of these
feathers," remarked Billy, as he bounced into the bed pillows that
night.

Happily, "coming events do not cast shadows" for sound sleepers.

Roque had departed for the city before the boys charged into the
breakfast room.

"He has gone to the store," announced Zorn, who uncovered his teeth an
extra inch, in compliment to his own humor.

"Let's go over to see Lieutenant Hume," proposed Billy, after breakfast.

"Just the ticket," agreed Henri, "I'm crazy to get a peep at the old
flying quarters again."

But Zorn objected to any move that Roque had not ordered.

The boys had to be satisfied with the prospect, for to run against
Zorn would be akin to tackling a mountain.

When Roque returned, sure enough, he was again playing the
merchant--horn, spectacles, and all.

"Ah, young sirs, kindly waiting for the weary worker?"

"Same old blarney," muttered Billy.

Zorn chuckled as he relieved the "merchant" of his hat and overcoat.

"Some time ago I believe I told you that here you were only balancing
on the edge of the great empire, and there might be an opportunity for
you to see much more of the country. The opportunity is at hand. I have
been called by trade interests further afield, and as I cannot consent
to a separation, you will continue as my companions."

In his hour of relaxation, Roque really enjoyed this sort of word play,
and he eyed the boys to see if they appreciated the fact that all of
the best actors were not on the stage.

He was sure of Zorn's sincere appreciation. This man had seen the chief
in many parts.

Henri accepted the cue, and, with a profound bow, and a hand on his
heart, replied in kind:

"My dear Herr Roque, we would grieve if you left us behind."

"What of you?" Roque turned to Billy.

"Oh, anything goes with me." The boy from Bangor always hit straight
from the bat.

The last evening of many in Hamburg was a very pleasant one to the
boys. Roque's intimate knowledge of London and Paris was displayed
in entertaining way, with no reference to his own exploits as the
cleverest conspirator that ever invaded court and palace. He expressed
regret that he had never seen America, and induced Billy to tell about
Boston and Bangor.

It may also be recorded that with this evening the boys unconsciously
said good-by to the character of the Hamburg merchant. They went far
with the many-sided man, but never again saw him in the rôle imposed by
this big city on the Elbe.

When the boys retired they left master and man--Roque and
Zorn--conversing before the fire. With the coming of the morning, the
journey to the unknown began, and the Aëroplane Scouts had no idea of
its purpose or their assignment in the new sphere of action.

That it would, however, include further conquest of the air they might
have guessed.




CHAPTER VI.

A FLYING VICTORY.


IT was a great day for the boys when they set foot in imperial Berlin,
with its palaces, art galleries, museums, parliament building,
monuments, magnificent parks, and over all its martial spirit.

Roque, by which name, it might be mentioned, he was not known in this
heart of the empire, soon demonstrated to his charges that he was the
man higher up by his manner of getting about, and the high cost of
living had no worries for him.

"Who'd have thought that we would be hitched up to a ten-time winner
like this?" Billy was content for the time being to be allied with
power.

Among the many who answered the summons of Roque in the intelligence
bureau, the young aviators were most interested in a score of blond,
blue-eyed, well-set-up Saxons, renowned as Zeppelin navigators, who
were destined to guide the "terrors of the air" in furtherance of
another raiding plan taking form in the fertile brain of the eminent
promoter of trouble for the enemy.

While the boys had faith only in the heavier-than-air machines, they
conceded that the risk taken by the Zeppelin crews entitled the latter
to brush elbows with the crack flyers of the other kind of bird craft.
It was also true that when a Zeppelin got anywhere it was a tremendous
factor in war. And it was no question but that the Fatherland had gone
Zeppelin mad.

Woe betide the hostile airmen who dropped the bomb on the Zeppelin
works at Friedrichshaven if Roque had the means of catching them. It
was only another score that he had marked up against Ardelle, whom
the master agent of the empire charged with planning this destructive
performance.

"Roque said he was going to show us where these gas cruisers grow,"
Henri advised Billy one evening, getting this news while his chum was
engaged in an argument with a Zeppelin worker.

"Something I've been wanting to see," exclaimed Billy. "I owe something
to a Zeppelin, even if it is like a balloon."

This last was a sort of side swipe at the man who had been on the other
side of the argument.

"There is one thing sure, these dirigibles can't camp out." This was
Billy's first remark in Friedrichshaven.

He was peering into a big steel-framed shed with a glass roof which
housed one of these grim engines of the air--a great cylinder flanked
by platforms. This newest of the huge airships was about the length of
a first-class battleship, and the opinion of the young aviator that it
could not drop anywhere and everywhere like the aëroplanes he drove was
not a prejudiced one.

When Henri had a look at the powerful motors he was impressed with
their capacity to drink up petrol at a most appalling rate.

"What's her top speed?" he asked one of the big fellows who had
traveled over from Berlin with them.

"Forty-five miles in the calm," was the reply.

"Gee!" exclaimed Billy. "We could get a seaplane home for breakfast
while they were waiting supper on you!"

"Yet," claimed the Zeppelin expert, "it's the car they're all afraid
of."

"It certainly does look like a scaremark," admitted Henri, who
remembered a certain evening on the Belgian coast, when he was one of
the company aboard a stranded hydroplane dragged ashore by the swinging
anchor of a Zeppelin, which loomed overhead like a cloud, and buzzed
like a million bees.

A gang of at least a hundred men swarmed about the shed when the order
issued for a trial trip of the new super-Zeppelin, a sample of the
fleet in course of building, and Roque carefully noted every detail of
equipment.

The gas chambers were fed with pure hydrogen, no common coal gas,
and many thousand cubic meters were in the flow of this one envelope
filling.

"Guess they'd have to carry a hydrogen factory around with this outfit
to keep it going," observed Billy, as he noted the elaborate process.

"Not that bad," advised the man at his elbow, "this gas can be
transported from the factory in cylinders under pressure."

"Just think of it," put in Henri, "I heard them say just now that it
took thirty gallons of petrol an hour to buzz these motors."

"Biggest thing I know in the air business. I wish Captain Johnson could
see an expense bill like this. He'd have a fit." Billy would, indeed,
have counted it a red-letter occasion if his old friend, and the boss
airman of Dover, were really at hand to take in this show.

To go aloft in an airship about which they were not thoroughly posted
was a brand-new experience for the boys, but they were not in the least
degree like the proverbial cat in a strange garret. It was easy riding,
and none of the guns pointed their way. Billy carried a memorandum of
a British military biplane, with a record of 10,000 miles, which Henri
and himself had once patched up, that had been hit by 250 rifle bullets
and sixty fragments of shells. He wondered if the immense craft in
which they were sailing could have floated with, proportionately, about
ten times that amount of lead poured into her. But Billy, of course,
did not then know much about Zeppelins.

Roque, however, was eminently well satisfied, particularly with the
improved method of distributing explosives where they would do the most
harm. The airship had a special armored compartment for bombs near the
propellers and a big gun mounted in front to destroy aëroplanes. "Get a
fleet of these over the English channel," he proclaimed, "and somebody
would think that hell had been moved upstairs!"

"I'll say this much," announced Billy, "I'd take an ocean voyage for my
health if I knew when they were coming."

"But if the fighting crowd over there had the date and the hour, I'll
promise you that the reception your fleet would receive would be warm
enough to boil an egg." This was Henri's prediction.

"We never advertise," grimly remarked Roque.

When the Zeppelin had completed her trial trip and had again been
housed by the small army of workmen, Roque informed the boys that he
was going to give them the chance on the morrow to show their mettle in
a biplane test, which was to decide the relative merits as to the speed
of two special designs.

"I am going to put you up to jockey the machine that I favor," he said,
"and, mind you, the aviators that will drive against you are among the
finest in our flying corps. I always pick my men by personally knowing
what they can do in any line of action. They seldom fail me, and it is
with you to make good."

"We're going some, Herr Roque, when we come up to your standard,"
replied Henri.

"See that you are 'going some' at the finish of the race to-morrow,"
laughed Roque.

"It will be because something breaks if we don't hit the high mark,"
assured Billy.

"Go over and size up your winged steed," directed Roque, pointing
to a hangar across the field. "Show them No. 3"--this to one of the
attendants.

"This is no mosquito," announced Billy, after a view of the fine lines
of "No. 3."

"Speed there, I tell you, old boy," was Henri's comment as he walked
around the rigging, "and carrying armor, too."

In an hour the boys had fully comprehended all the new features of this
up-to-the-minute machine. They had been builders themselves and knew a
good stroke of the business when they saw it.

Returning across the field, Billy and Henri were introduced to the
rival aviators by Roque. The German airmen were a jolly pair, and
showed by the professional courtesy they exhibited to the two of their
kind that the coming contest was wholly a friendly one, and the results
to be of value to the flying corps.

"No. 2 is a little older than your machine," was the greeting of one of
the Teuton experts, "but it can hold its own."

Roque, speaking for his champions, gaily disposed of this claim:

"Keep your eyes open to-morrow, Fritz, or you will get lost somewhere
in the rear."

"No fear, sir; there are no cobwebs on No. 2."

"What are they talking about, Buddy?" asked Billy.

"They just think they are going to beat us, that's all," interpreted
Henri.

A bright clear morning presented itself for the aërial race, and Lake
Constance lay like a broad mirror under the sunlight. The course was
set due north and straightaway for twenty miles, and the turn fixed at
a high point called Round Top, upon which, Roque informed the boys, a
tall flagstaff had been mounted.

There were no preliminary trials, for both machines had been carefully
groomed, and each was as fit as a fiddle.

With the aviators up the biplanes scudded down the field for the rise,
and got away upon almost equal terms, the German drivers slightly in
the lead, through better acquaintance with the lay of the ground. They
trailed a yellow streamer, while the boys floated a band of black.

The ascent reached 2,000 feet, when the machines darted north like
arrows. Roque and a group of officers about him followed the speeders
through field glasses.

"They would run a swallow to death," remarked the secret agent to the
aviation lieutenant at his side.

The aëroplanes had dwindled in the vision to mere specks, and there was
no telling which was in the fore.

"Ah, they are headed back!" cried Roque. "Now for the show-down."

The glasses revealed the specks moving twin-like, and such was the
terrific onrush that the crowd surging in the field soon caught a view
of the contestants in growing size.

One enthusiast shouted: "Fritz will shut them out!"

But the glasses did not uphold the prediction. The machine with the
black streamer was evidently using the reserve power that had been
claimed for the newer make, and Henri was getting the best out of it.
Yet the first-born craft was being handled in a masterly manner, had
plenty of go to spare, and five miles still rolled between the speeders
and the finish flag.

Now four, and the machines were bow and bow; now three, and the yellow
band flapped a few feet behind the black; now two, now within the mile,
and the whirring of the motors audible to the nerve-strained watchers
below--then the close finish--and the white-faced pilot crowned victor
was Billy Barry of Bangor, U. S. A.!

When the aëroplanes made landing, Roque pushed through the crowd and
favored the Aëroplane Scouts with a forcible slap between the shoulders.

The victors were quick enough to extend hands to the vanquished.

"My friend," cried Billy, giving Fritz a warm grip, "it was only fifty
feet, and it was the new motors that did it."

Then the crowd cheered, while the efficiency committee agreed with
Roque that "No. 3" was the machine to be many times duplicated.

"That was something over a mile a minute coming back, I guess," figured
Billy.

"The fastest heavy craft I ever sailed in," was Henri's expressed
belief.

"I think you youngsters could make a living here if I were to bounce
you," said Roque, who had been talking to some of the factory chiefs.
"But you are hooked to my train for a while yet. And that reminds me
that the mentioned train starts in the direction of Austria in the next
two hours. Vienna is not a slow place, you will find."

As Roque was likely to jump anywhere at the drop of a hat, the boys in
his company had long since lost the emotion of surprise.

Perpetual motion had become a habit with them.

In the Austrian capital the travelers encountered many invalids from
the front, men who limped a little, had an arm in a sling, or a
bandaged head. The Viennese on the surface did not seem to be greatly
impressed by the tragedy of the war--evidently becoming used to it--yet
the determination to fight to the finish, while not as grim as in
Berlin, was there, nevertheless.

Another thing that impressed the boys was that here foreign terms were
still much in evidence--French and English. In Berlin it was different.

As Billy said, "we're in a better mixing town." He and Henri were
told that quite a number of medical and art students from America had
decided that Vienna was safe enough for them, but Roque kept his airmen
close under his wing, and they had no opportunity to pass even the time
of day with any of the U. S. A. crowd.

They had no present desire, however, to attempt a bolt from Roque and
did not believe, anyway, that their detention was just then seriously
affecting their health.

"Time enough to run," was Billy's philosophy, "when his nobs begins to
kick in our ribs."

They were seeing plenty to keep them interested, the arrival of
sleeping-car trains bringing the wounded to the capital, the movement
of troops bound for the Polish or Galician front, the daily sights of
the Ring and the Kartnerstrasse.

Roque, as usual, was up to his eyes in war business, ever behind the
scenes but ever moving, for there is close military coöperation between
Germany and Austria-Hungary. All interests related to the war have been
pooled--one empire gives to the other what can be spared. The king-pin
of secret agents from Berlin served a purpose wherever he went.

He sat in no open councils, but privately conducted many of his own,
was constantly receiving and dispatching messages, and the devices he
originated to aid his disguised subordinates burrowing for information
in hostile territory were too numerous for detail. These latter
operations were not accompanied by band music, for officially this live
wire had no identity.

"If that man took a pot shot at the ocean you would never know in what
direction he was aiming unless you happened to see the splash." Billy
was not far from being right in the summing up of Roque's methods.

Within the next hour the boys "happened to see the splash."

A uniformed messenger handed Roque a telegram. The secret agent hastily
read it, and sprang to his feet, his eyes aglow with triumphant
satisfaction.

"I've got Mr. Ardelle in a stone box at last!"




CHAPTER VII.

THE RAIN OF BOMBS.


THE boys in silence watched the secret agent as he further displayed
his gratification over the news conveyed in the telegram by snapping
his fingers and slapping his knees, completing the performance by
vigorous puffing of a big black cigar, of which brand he always carried
a plentiful supply.

Billy and Henri were just aching to learn more about the reported
capture of Anglin (Ardelle), just where the "stone box" that held him
was located, and how the "smiling sleuth" had happened to run into a
net that he could not break through.

But they were well aware that it would not be a bit of use to seek
the eagerly desired information in advance of Roque's disposition to
give it, and they did not dare openly to show personal interest in the
matter.

It was not until the master plotter had burned his cigar to inch
measure that he thought to address the lads, fixing expectant gaze upon
him.

"They jugged the fox in Alsace, on the way to his home den, and filled
up, I suppose, with some choice morsels to regale the enemy."

"Maybe it's another case of 'now you see him and now you don't.'" It
was Henri who plucked up courage to say this.

"Not this time," insisted Roque. "He is tightly in the toils, and never
a chance to show his cunning. His course is run."

It soon became evident that the speaker proposed to be "in at the
death," as fox chasers call the finish.

In less than two hours Vienna, the city gay and unafraid, was behind
the three travelers, and their next goal the imperial territory of
Alsace-Lorraine.

Into Lower-Alsace, on the last leg of the journey, Roque and the boys
took to horse, with cavalry escort. They were again on real fighting
ground.

Henri picked out of a conversation between Roque and the captain of
the troop the words "Homberg castle," later that a group of important
German officers resided there, and still later that within those walls
Anglin was a prisoner.

Billy was immediately posted by his chum as to the situation.

Upon arrival at the castle, Roque, in that mysterious but effective way
of his, established his footing as a privileged guest, and his first
move was to pass the guard at the door of the strong-room, where his
chief rival in the art peculiar was confined.

The boys without reprimand were close at the heels of the German agent.

Anglin was sitting on a bench, under the checkered light of a high,
barred window. While his face showed harsh lines of great strain, the
inevitable smile was in his eyes. He arose instantly from the bench,
and bowed gracefully to the foe who confronted him.

"Monsieur, you are welcome." This to Roque. Upon the boys he bestowed
not the slightest recognition.

Roque, not to be outgeneraled as a diplomat, inclined his head in
return.

"I came a long way to visit you, sir," he politely stated, "and would
have regretted had you felt otherwise than you have intimated."

This fencing with buttons on the foils was soon succeeded by the sharp
points unprotected.

"Ardelle, the longer the breath is in you the more you can tell; is the
breath worth the telling?"

"You speak in riddles, Monsieur," quietly replied the prisoner.

"Do you deny that you are Ardelle?" demanded Roque.

"Am I now on trial?" was the counter-question.

Roque extended a menacing finger. "Have a care, man!" he thundered.

The prisoner calmly ignored the growing wrath of his arch-enemy,
shrugged his shoulders, and with a wave of the hand indicated that
continued argument was useless.

"You will have until to-morrow morning to decide whether you will
accept me as an advocate or an accuser."

The Frenchman turned wearily toward the window, and with his hands
folded behind him stood watching through the bars the little gray
cloudlets pushing their way through the blue expanse of the sky. It
might be that this view would not concern him after the morrow. He was
thus engaged when Roque stamped his way out of the room. Henri would
have paused in the hope of one look from Anglin but the latter seemed
wholly unconscious of the presence of the lads.

Under the steely exterior of Roque, the milk of human kindness had not
wholly curdled, for he sadly said, half to himself and half to his boy
companions:

"He must expect no more than I could expect; when we fail we fail
alone, and so alone must we suffer."

It was about two o'clock in the morning of the day when Anglin, or
Ardelle, was expected to read his fate in the eyes of those assembled
as a military tribunal. The identity of the prisoner was, no doubt,
fully established, for the boys had noted the presence in the assembly
hall earlier in the night of the sandy-topped man who had started the
hue and cry in the Bremen hotel, where the French sleuth was posing as
a public singer.

Billy and Henri were tossing in uneasy slumber. The only sounds inside
the castle were occasional snores from adjoining apartments and from
the outside the whinnying and stamping of the cavalry horses.

Suddenly the quiet was shattered as if by a thunderbolt. The boys
literally tumbled out of bed, gasping from the shock. A blinding flash
at the windows and another crash.

Soul-shaking cries of "fire!" resounded throughout the building, and
through the halls swept volumes of smoke.

The celebrated ancient furniture in the castle, it having been the
summer residence of French nobility, was fine food for flames, and the
red destroyer soon raged in conflagration.

Crash after crash, and with each concussion myriad sparks shot through
great holes in the castle roof.

Bombs were being dropped from aloft.

The boys hastened with other occupants of the upper floors to the broad
staircase in front of the structure. There they paused, elbowed against
the wall by those pressing from the rear. There was no wild confusion
or panic behind them, however, such as might have ensued under the same
terrifying circumstances with other than trained soldiers involved.
When Billy and Henri took to the wall at the head of the staircase
it was a voluntary act on their part. The same thought with both had
impelled the pause:

Had Anglin been released from the fiery vortex or still restrained by
iron bolts and bars?

The room in which the captive was held faced a gallery running at right
angles from the main stairway.

Pulling their jackets up and over their heads, the boys plunged through
the wall of smoke on mission of rescue--a mission without result, for
the door of the place of confinement was wide open, and no one was
there.

The rescuing party of two then turned their intent upon themselves,
and none too quickly, for they had hardly won safety when the castle
enclosure was wholly enveloped by consuming flame.

Farm buildings adjoining were also ablaze, and the wide highway
stretching away to the east showed whitely in the glare.

In the red canopy overhead winged shadows whirred and whirled, dipped
and leaped.

Billy and Henri proceeded down the road to escape the growing heat and
rolling smoke. When the roaring of the fire had somewhat lessened in
their hearing, they detected a familiar hum, just ahead and closing
down beyond the border of the rising mist of the morning.

As aviators, the boys were instantly aware that an aëroplane was
working near and the proof was immediately furnished by the appearance
of the aircraft itself, swooping into the circle of illumination,
skimming close to the surface of the highway.

The lads sprang forward to greet the aërial visitor, and as they did so
a tall figure, hatless and coatless, leaped from the cover of a ditch
nearby, ran like a deer alongside the skimming biplane, and vaulted
into the frame behind the daring navigator.

As the machine took the uplift, Billy and Henri were so close, and the
fire-flow so vivid, that they plainly saw the faces of both the saver
and the saved.

The man who had jumped into the machine was Anglin; the aviator was
Gilbert Le Fane, the noted airman of Rouen, whom our boys had once
followed in flight from Havre to Paris.

From the fire zone there was coming a hurrying body of men, and rifles
began to spit lead at the swiftly rising aircraft. Too late, though,
to reach the height attained by the biplane. A shrill yell of defiance
floated back on the breeze of the morning, and deep and heavy were the
expressions of baffled rage by those grouped in the road below.

Roque and the sandy-haired assistant could be heard above all the rest.

The boys were again in the rôle of innocent bystanders.

When the sun later replaced the flames in lighting up the sky, not a
trace of the French airmen could be sighted, save the marks of their
raid--the blackened ruin of the castle and smouldering remains of the
adjoining buildings.

Investigation instituted by Roque related solely to the escape of the
prisoner. To put a quietus on his rival had drawn him from afar, and
here again the elusive Frenchman had been jerked out of his clutches,
this time into the very sky.

With the fall of the first bomb the single night guard over the captive
had drawn the bolts that he might be ready to quit his post upon first
order with the Frenchman in close custody. The second bomb so stunned
the guard that he knew no more until regaining consciousness in the
rear courtyard outside. He could only account for his presence there
by the belief that the man over whom he had held watch had picked him
up and carried him out of danger. There was a back way that could be
traveled, smoke hidden, without observation.

"But how about the aëroplanes dipping just at the right time and place
to carry him off?"

This was the point that especially puzzled Roque.

A farmer boy, listening, open-mouthed, to the questioning, offered a
solution.

"You see, Monsieur," he bashfully explained, "it was a ghostly noise
that was making between the big noises, like the wind blowing through
the neck of a bottle stuck in a knot hole. I heard it in the road, a
long way."

It occurred to the boys that this distress signal must have been given
before they got away from the roar of the fire, or while they were
probing the smoke in the gallery to reach Anglin.

"They were flying mighty close down and could probably hear a howl
like that, if they were listening for it and knew what it meant." This
opinion was advanced by Billy.

"I don't much believe they could hear a call from the ground, unless it
came from the business end of a gun." Henri was the doubter.

"It is no use to argue," said Roque. "The fact remains that the air
fellow had his bearings, and he got the lead from somewhere. I am not
giving him credit for being a mind reader."

"That reminds me, Mr. Roque," remarked Billy, "that we might test this
bearing business by a little air trip somewhere and soon."

"I have just such a thing in thought," grimly advised Roque, "and I
will warrant that you will hear a few ground sounds before the quitting
minute. We are going to take a down look at Belfort."

Now Belfort is a French fortress, where the soldiers in red and blue
had been finding security every time they were rolled back from the
plains of upper Alsace.

A tremendous amount of gunpowder had been burned on the flat ground
in front of this stronghold, and our boys were in for a smell of
it--something that would recall perilous travel with Colonel Bainbridge
and Sergeant Scott in previous campaigns.

A wire to Friedrichshaven had started on the way the makes of biplanes
that Billy called "Roque's best bet" since the day of the famous race
over Lake Constance.

"Business will soon be looking up," joked Henri, when he heard of the
order for the shipment of "No. 3's."

The presence of Ardelle in this region, extreme southwestern
Germany, had raised suspicion in the mind of Roque that some special
demonstration was brewing, and the lurid performance of the French
airmen in blowing the roof from over his head served to further elevate
the confirmed idea that trouble and the French agent always traveled
together.

Roque was not here to mix in the actual military operations--that was
not his business, but he was ever open-eyed on the trail of the boss
gamester on the other side. He had expected this time to put his rival
on the safe side of the ground, but spades did not prove to be trumps.

Somewhere in the gap of Belfort, as the valley south of the Vosges
mountains is popularly known, Ardelle was, no doubt, preparing for
another comeback, and Roque was scheming to meet him halfway.

There was no chance to get under the guns of the frowning fortress
beyond the frontier, so the only way to size up the situation was to go
over them.

Here was where flying experts jumped to the front.




CHAPTER VIII.

ALONG THE BATTLE LINE.


WITH the arrival of the biplanes from the factory, the Boy Aviators
were kept busy with brief test flights over valley and plain, awaiting
the convenience of Roque for the wider sweep he was planning. It
developed that the boys were expected to navigate separately on this
occasion, Billy to pilot Roque himself, and Henri to be accompanied
by one Renos, who had been awarded a service badge of honor for his
work as an aërial observer in giving first warning of the advance of a
French division against Burnhaupt, which saved the day for the Germans.

"The seaplane is the rig for weight carrying," exclaimed Roque, in
accounting for this assignment, "but these machines, as you know, are
solely in the speed class, and it is many chances to one that we will
be compelled to tax every ounce of power before we get through. So we
have no use for deadwood."

Renos, who was to sit behind Henri, was the silent man of the
expedition, as far as talking was concerned, but when it came to be
up and doing he could be counted on to the limit. He was a human
route-box of the Sundgau, the fighting territory, and very much at home
in a flying machine. When the two machines one morning flew over the
German frontier, in compliance with the "ready" order of Roque, Renos'
knees were crossed by a wicked-looking rifle, and of the party he was
the only one armed.

Billy, observing this war-like figure, asked Roque if he expected to
get into close quarters on this trip.

"Not unless some of the bomb-throwing crowd that scarred the landscape
the other night should cross our path," replied the secret agent.

As Renos was the qualified guide, the biplane bearing him went to the
front, and Henri received overshoulder directions as to the course to
be maintained.

The apparent reason why the German expert did not pilot the craft
himself was that he wanted a loose hand in case of emergency, and a
free eye for the panorama below. He was satisfied, too, that one as
good as the best was doing the steering.

Henri was instructed to keep a respectful distance from the near
mountain peaks, where the French had mounted artillery, for one round
from these guns, close enough, would have ended the flight and the
flyers there and then.

But Roque and Renos kept constant vigil with glasses, and Billy
wondered that the pair did not get a crick in the neck with all the
head-turning they did.

A sharp order advised the pilots to send the biplanes farther aloft,
and circle. The French fortress of Belfort could be seen directly
underneath.

The aviators well knew that an explosion close to an aëroplane is often
sufficient, through the force of the air concussion alone, to bring
it down, and they knew they could not chance a close shot from the
long-range guns in the fort.

Though the machines now evoluted at greater height, the powerful
glasses enabled the observers to plainly distinguish the movements
below.

It was quickly manifested that the garrison lookout had become aware of
the aërial visitation, and that they did not approve of the color of
the hovering aircraft.

A couple of smokeballs ascended and burst in the center of a cloudrack
far to the right of the machine. Renos broke his record for silence
with a shrill cackle.

"Save your powder, you numbskulls," he shouted for his own satisfaction.

Roque seemed oblivious of the gunplay below. As the biplane described
great circles over the fort, he kept his glasses steadily aimed at a
point in the enclosure over which the flag was floating.

The men who emerged from the officers' quarters all wore the French
uniform.

Roque had evidently cleared up a disturbing point in his mind as he
muttered something about a "fool story," and "I might have known there
was nothing to it."

Having satisfied himself that it was still an independent little war at
this remote point from the main field of operations, and that he had
been misled by some advices previously received, the chief observer
passed the word to his pilot to back-track, at the same time giving
signal to the companion biplane.

As the machines swung around for the return flight, and drew closer
together, Renos gave a megaphone yell through a hollow formed by his
hands:

"Speed for your lives, they're on the wing!"

Above the gentle slopes on the west, leading to the summit of the
mountain ranges, aircraft had arisen, looking, at a distance, like
black dragonflies.

At the same moment, the invading biplanes also had a reminder to hurry
from the fortress they were leaving behind.

A shell burst seemingly quite close to the machine Henri was driving,
and the craft dipped far to one side.

Billy's heart beat up to his throat when he saw the break in the
flight.

But his was an exulting cry when the momentarily stricken flyer
righted, and bored ahead.

"Glory be!" hoarsely rejoiced the boy from Bangor, when his chum again
drew to the upper level.

Seventy miles an hour was the clip of the fleeing biplanes, and no less
speedy the onrush of the aircraft from the slopes.

"Steady, and a little to the right," Renos instructed Henri.

The observer was resting the rifle barrel on the rigging, awaiting a
broadside target.

Sping! One of the attacking aviators was first with his rifle, and the
bullet nicked the armored side of the German craft. Sput! Henri heard
an angry exclamation behind him, and shifted an eye long enough to see
that Renos was nursing a bloody wrist on his knee.

"How hard are you hit?" was the anxious question of the young pilot.

"Nothing to kill," replied the observer, as he used his uninjured
fingers and his teeth in knotting a handkerchief above the wound so as
to compress the severed artery.

With the utmost calm he then deliberately used his left hand in rifle
aiming, and sent a bullet into the nearest hostile machine.

Whether the shot crippled the pilot of the leading pursuer, or whether
it was the menace of the heavy howitzers on the German frontier, which
was now of short approach--the French flyers suddenly ceased to be
aggressive, and with a parting salute of rifle practice, turned back
toward their mountain station, while the German machines dashed across
the line of safety.

Upon landing Billy indulged in a sort of war dance around his chum.

"Thought you were gone that time, sure, Buddy," he cried, "and it was
simply great the way you pulled out of the hole."

"I guess I was stunned for a minute, as though somebody had hit me with
a hammer," explained Henri, "but when I found the controls were still
working, it was a bracer, I tell you. And if there isn't a cool head"
(nodding toward Renos, who was inspecting his wounded wrist) "I never
saw one. He stretched his arms over me ready to take hold if I failed
to rally, and did it as a matter of course. Not a tremble about him,
either."

"What do you think of the No. 3's now, boys?" queried Roque, when he
had dispatched Renos in search of a surgeon.

"They're dandies, all right," promptly agreed the happy pilots.

"They will do to hunt trouble with, anyhow," laughed the secret agent,
who was immensely pleased with the flying achievements of the day.

Roque, pluming himself with the idea that, though he did not hold
Ardelle when he had that artful dodger under his thumb, he had at
least chased his rival out of the empire; and, having also eased his
mind as to the report of a new element in the Alsace campaign, he was
impatient in his preparation for departure. Master of detail though he
was, the big moves only appealed to him.

A great battle was raging at Soissons, on the Aisne river, in France,
and Roque had in mind an aërial journey north, and quick flight across
the border to the scene of the fierce artillery duel, following the
line of march of the mighty force under General von Kluck.

The crippled Renos was replaced in the observer's perch by an aviator
known as Schneider, a very daredevil, and who was at first inclined
to doubt that the boy with whom he was paired had sufficient skill
and courage to pilot a military biplane in an active war zone. Henri
very quickly convinced the doubter that he was very much older than he
looked when it came to the fine points of aëroplaning, and, too, that
when there was an emergency demand for "sand" the youngster had plenty
to spare. Schneider had additional assurance of capacity when he was
advised that both of the lads carried Roque's indorsement of efficiency.

It was a bitter struggle that the Aëroplane Scouts were to witness at
Soissons, and six days of it had already passed. The earth was still
dropping on many graves of the German fallen, and yet, sprawling in
attitudes along the heights, in the deep-cut gorges of the plateau,
and across the flat valley bed were French infantrymen in their
far-to-be-seen red-and-blue uniforms, swarthy-faced Turcos, colonials,
Alpine riflemen, and bearded territorials.

At staff headquarters, in the first officer that passed near them the
boys recognized a familiar figure, no other than Colonel Muller, whom
they had first met in far-away Texas, U. S. A., on the day of the
record flight, and again in the hangar camp at Hamburg.

Billy impulsively stepped forward. "How do you do, Colonel?"

The officer instantly turned in his stride to inspect the speaker.
"Hello, Boy Aviator," was his hearty greeting. "How under the sun did
you ever get here?"

"Same old way," said Billy, "the airline, of course."

"And here's the other one," the colonel reaching for Henri's shoulder.

"By the way," continued the big soldier, "this must be a field day for
flyers. Here, Hume, come and see what the wind brought in."

The officer addressed moved at quickstep in response to this
invitation. It was the aviation lieutenant from Hamburg. He grinned
from ear to ear when he laid eyes on his former charges.

"Can't lose you if I try," he exclaimed. "Have you enlisted with us?"

"No," laughed Billy, "we're still driving cars for the good merchant
from your town," with the backward point of the thumb at Roque, who was
engaged in close confab with a group of staff members near by.

"Did you blow in with Schneider, too?" asked the lieutenant. "I just
want to say that you will bore a hole in a stone wall sometime if you
train with that fellow. Nature didn't give him red hair without reason."

"Now that you are here," broke in the colonel, "you must not be allowed
to get out of practice. I expect that one of you will have to give me a
ride along the front before long. I have lost three horses this week."

"We'll do our best to oblige you, colonel," volunteered Billy.

It was no merry jest, that ride Billy gave the colonel!

At the time, the French retained a foothold north of the river at only
one point--St. Paul--where the bridge from Soissons crosses, and this
by a perilous margin, since the bridgehead was completely commanded by
German artillery on the heights.

The battlefield entire covered a front of about seven miles, the center
and eastern flank a high, level plateau rising steeply a couple of
hundred feet from the valley of the Aisne. On the western side a deep
valley ran northward, bounded on either side by turnpikes. An airman
taking the big curve of the river would not be considered a good risk
for a well-regulated insurance company.

But it could be done--and Billy Barry furnished the proof.

When the next day broke a bloody conflict was raging between the two
turnpikes, the French infantry attack on German trenches preceded by a
terrible artillery bombardment, a storm of shell and shrapnel.

Colonel Muller beckoned Billy to his side. They stood together on the
heights from which the French had been expelled only the day before.

"My boy," was the brisk address of the officer, making a field-glass
survey of the smoke-crowned landscape, "I am going down the line, and I
am to do the distance in an aëroplane. Is it you or Schneider who will
do the driving?"

"You gave me the first call yesterday," reminded Billy.

"That was my intent, and it still holds. I was only seeking to learn if
you were of the same mind since that powder mill let loose down there."

"I well know the odor of it," stoutly maintained Billy, "and it doesn't
weaken my knees."

The young aviator, accepting the matter as settled, hastened toward
staff headquarters. "Mr. Roque," he excitedly called, "Colonel Muller
wants to try one of the No. 3's this morning, and I'm to pilot."

The secret agent lifted his eyebrows as though surprised, but he really
was not. The arrangement had already been made.

"Say, Buddy, this is rough that we can't both go; and suppose something
should happen to you?" Henri had just realized that something was up,
in which his chum was vitally concerned.

"Don't you worry, pard," consoled Billy, "it is only a little spin of a
few miles, and we'll be back in no time."

"Wish it was me," sighed Schneider, for this firebrand guessed that it
would be a red-hot journey.

As the biplane swept into the breeze current, trending to the river,
which then was running brimful, and in many places overflowing its
banks between the two armies, Colonel Muller advised Billy to keep the
machine climbing for the time being, as a terrific fusillade was in
progress in the distance of the next two miles, the shells hurtling
through the air like lighted express trains. In the three steep-sided
ravines that deeply notched the plateau on the east French troopers
swarmed like bees, and at this cover the big German guns were blindly
banging.

"We can't see much, Colonel, at two thousand feet," complained Billy.

"You would see nothing at all if we ran into one of those fragments of
shells," coolly suggested the officer, "but never mind, you will do
some diving in a few minutes."

Billy got the signal to dip at the juncture of the turnpikes, and to
hold a level and lower course along the line of battle, marked here by
infantry fighting between the seemingly crawling columns far below.

"Down!"

The colonel's order was peremptory, and Billy forthwith volplaned
toward the earth.




CHAPTER IX.

THE LUMINOUS KITE.


THE biplane had hardly scudded its length on the turnpike, when the
colonel leaped from the machine, his sudden appearance greeted by
salvos, both of cheers and an extra round of rifle discharge.

Billy sat like a statue in the machine, facing a reserve force of grim,
gray-garbed veterans standing at attention.

The front rank soldiers eyed the boy curiously, no doubt wondering that
one of his years should be serving in the capacity of a full-fledged
military aviator on a mission so supremely perilous.

Billy could not understand what Colonel Muller was saying to the
commanding officer of this regiment, but he could see the effects
rippling through the serried lines, a stiffening of attitude, a closer
grip of rifle stock and squaring of shoulders.

The column, solid and compact, the German practice of close formation,
moved with clockwork precision down the field to back the general
charge against the living wall that barred the way.

"Charge! Charge!" The cry from a thousand throats.

The forces mixed in a struggling, swaying mass, with indescribable
noises, the clashing of steel and the squealing of horses, for cavalry
had joined the fray.

Billy jumped out of the machine into the dusty road, the sole spectator
there of the conflict that raged but a half mile distant.

Colonel Muller had taken to horse and was riding furiously to rally
incoming reinforcements for the gray column.

A rattle cut into the sound ruck--the machine guns of the Germans had
turned loose, and men were mowed down like ripened corn.

But fainter now in Billy's ears grew the roar of violent contention,
alternate advance and retreat serving to shift the tide of battle
further northward, and finally stemmed by the final demonstration of
the day at Soissons bridge.

Barring the occasional wild gallop of a riderless horse down the road,
the young aviator saw no signs of life about him, and he was too far
away to hear the groans of the wounded on the sodden field now enfolded
by the gathering gloom of evening.

"I wonder if the colonel has forgotten that his carriage is waiting,"
thought Billy, trying a bit of mental cheer to relieve the strain of
his trying position.

The colonel, however, had not lost his memory along with his hat, for
even then a foam-flecked horse was bringing him back to the driver of
his aërial chariot. Mud-bespattered from head to foot, he sent a hearty
hail ahead of the pounding hoofs of his weary mount.

"Ahoy, my stranded mariner: is supper ready?"

That reminded Billy of a decided vacancy under his belt, but the glad
sight of the colonel was the best tonic for a drooping spirit.

"We will wheel this airship out of the way for a spell and have a bite
to eat in the trenches."

Concealing the biplane behind a clump of bushes the colonel gave Billy
a hand-up, and the horse cantered away with its double burden in the
direction of the slopes.

It was about 7:30 when the colonel and Billy climbed over the slippery
slopes to the line of reserve trenches, lowered themselves into one of
these holes in the ground, and it was evident that the occupants knew
how to convert a ditch into a home.

This trench had a head cover formed of cross-beams, overlaid with
branches and earth--a sure protection against shrapnel. There was a
long bench of telegraph poles, little cupboards for cartridges and kit,
and ramps for reclining chairs or couches, and drains to carry off the
rain.

"Come into our parlor, colonel," invited one of the soldiers, leading
the way into a subterranean chamber, which was warmed by a fire in an
old perforated petroleum tin.

"It is wonderful what ingenuity and labor can accomplish out of the
most unpromising material," observed the colonel.

"Made in Germany, colonel," laughed one of the veterans, "no matter
where you put them."

From the business end of the trench a hot meal was speedily produced
for the visitors, adding another touch of surprise for Billy.

"Well, my lad, we must report to the general," announced the colonel,
who had politely denied the petition of the trench veterans that he try
one of their couches for the night.

"You don't mind an air trip in the dark, do you?" inquired the colonel.

"Not a bit," assured Billy, "I've made many a one."

It was quite pitch black when the colonel and Billy rode back across
the plain, but the horse was sure-footed, and the way was fitfully
lighted by the occasional upshoot of rockets that left a long green
stream of stars, revealing the now silent battlefield and its dreadful
record of uncounted dead.

While Billy flourished an electric torch in giving the biplane a
careful look over, the colonel bestowed a playful slap on the flank of
the faithful horse, which sent the animal trotting up the road.

"He knows his number and troop as well as I do, and will go as
straight as a die to the feed trough," asserted the colonel.

"Are you ready, boy?"

"Trim as a ship, colonel."

With a flare on the compass, rising high, Billy held the nose of the
biplane in the direction of the heights that centered headquarters.

Small red sparks glowed in the trenches below, and the upper darkness
was ever and anon split by signal rockets and leaping flames of light
from countless campfires.

Billy, with the aid of the small searchlight in the bow of the
biplane, found safe landing, also insuring a sight of the colors to
the sentries, who might otherwise be tempted to take a pot shot at the
winged, midnight visitor.

Henri was the first to hear the whirr of the incoming aircraft, for
which he had for hours held an open ear.

"Here you are at last!" he exclaimed, making an open-arm break for his
flying partner. "You haven't lost an eye, or a leg, or anything, have
you?" he anxiously inquired.

"Sound as an Uncle Sam dollar, old boy," assured Billy. "But you just
bet I'm sleepy."

"I believe even Roque was uneasy about you," said Henri, as he insisted
on giving Billy's blanket a snug tug.

That the secret agent proposed to reserve the services of the young
aviators to himself thereafter and during their stay in this locality
was made manifest when he told them the next day to make ready for a
quick departure in the biplanes. As usual, he furnished no advance
particulars.

It appeared that Schneider was also to figure in the expedition in a
capacity indicated by his employment of oiling and polishing a service
rifle of the 16-shot brand, and the display of a pair of long-barreled
revolvers stuck in his belt.

"He looks like an arsenal on parade," commented Billy when the
red-haired flyer, in war-like array, passed on the way to conference
with Roque.

"There is no peaceful intent about that get-up," admitted Henri. "And
let me make another prediction," he continued, still proud of his last
previous success as a prophet, "this isn't going to be any pink tea or
garden party to which we're going."

"What a head you have," said Billy, beaming with mock admiration.

There was a decided lull in the fighting this day--the ninth since the
continuous combat had been commenced, as the soldiers of the two armies
were apparently resting on their arms. Some fresh planning, no doubt,
was in progress.

The boys wandered around the camp, restlessly anticipating the expected
summons from Roque. The latter, however, had not picked daylight in
which to operate, for it was long past nightfall when Schneider sought
and advised the boys that the starting time had arrived.

The moon was working full time when the biplanes set their course,
following the turnpike toward La Fere.

Above a farm, which had practically been razed, and on the edge of a
ruined district, both Roque and Schneider signaled the pilots to lower
the flight, and the biplanes circled groundward, landing near a row
of stunted willow trees. They showed no lights, and with the motors
silenced lay hidden behind a huge pile of debris, close to a wrecked
dwelling, so close that the full moon shining through the shattered
roof gave the aviators a dim vision of hopeless confusion, cooking pots
and children's toys, broken clocks and tables, knives, forks and books
strewn on the floor, beds and everything awry.

Billy and Henri had as yet no inkling of the purpose of this mysterious
proceeding in which they were engaged. Their companions did not seem to
be in a hurry, either, to enlighten them. Roque and Schneider appeared
intent in upward gaze, perhaps hoping that the moon and a dense bank of
clouds forming near would soon come together. As a matter of fact, a
total eclipse of the great orb above did follow, with the effect of the
sudden blowing out of the one lamp in an otherwise dark room.

Curious to relate, it was not long until the moon was replaced in the
now black canopy by a small but quite silvery brilliant imitation of
the big illuminant.

The diamond-shaped light in the lowering sky flashed this way and that,
as if responding to the manipulation of an aërial cable.

Roque was not puzzling about the appearance of the dancing light; it
was the message that it conveyed which baffled him, sent, as it were,
from within the German lines, and, maybe, of vital concern--aid and
comfort to the enemy.

Sentries on the heights had reported night after night of this queer,
intermittent flashing in this very place, and when Roque heard of it,
he instantly comprehended the meaning.

Some spy within the lines was using a luminous kite to signal
information of value to the foe.

This is what had brought the secret agent, an adept in the same kind of
game, flying through the night to scotch the play and the player.

Roque and Schneider skirted the ruins, and stumbled over the plowed
ground with all the haste that such rough going permitted. The boys,
free of any order to stay where they were, cautiously brought the rear.
They were mighty curious to see what was going to happen.

Schneider had taken the electric torch from under the pilot's seat in
one of the biplanes, and it had occurred to Billy to follow suit.
This precaution served to save the party an ugly tumble or two into
forbidding ditches.

The still-hunters had just emerged into a road with a wonderful avenue
of trees. The kite telegrapher's hidden nest was near at hand. The
position of the kite itself indicated that.

A streak of moonlight breaking through a cloud-rift revealed Roque and
Schneider kneeling in the road, and there was a glint of a leveled
rifle barrel.

The boys backed up against a tree, expecting momentarily to hear the
whip-like crack of the gun. But instead came the bark of a dog--one
shrill yelp, then silence again.

The luminous kite, unleashed, followed the moon into the clouds. Roque
and Schneider dashed forward, but for nothing else than to use the
electric torch in locating a half-loaf of bread, some cheese crumbs and
a ball of cord.

The sentry dog had saved its master!

"Nothing to be gained in chasing that fox to-night," growled Roque.
"He's deep in the brush before this."

"I'd like to have got a pop at the dog, at least," complained
Schneider, patting the stock of his rifle.

The boys having no desire to be the victims of any mistake of identity,
marched forward, Billy waving the electric torch, and calling to Roque:

"It's us."

The passwords were unnecessary, for Roque knew all the time the boys
were trailing him, but was restrained from objecting by fear of some
word reaching the ear of the man they were stalking.

"You gadabouts," he admonished, "you should have been guarding the
biplanes instead of prowling around in the dark like this."

The tone of the reprimand, however, was not one of great severity. The
boys had disobeyed no order, for none had been given.

"As soon as day breaks," said Roque, as they plodded wearily down the
road, "we will continue the hunt in the machines, though I doubt very
much whether it will amount to more than a waste of time."

"If I see a man with a dog underneath us, just bring me within rifle
shot, young man, and I will show you something fancy in the way of
gunning."

Henri, whom Schneider was addressing, mentally resolved that he would
be in no haste to perform as suggested.

Conditions, however, were reversed long before this test could be made.
Indeed, the reversal, with the dawn, was at hand. The hunters were the
hunted.

The thud of iron-shod hoofs, the clank of sabers--a troop of cavalry
charging through the wooded avenue--four madly racing footmen in the
furrowed field.

Full two hundred yards between them and the biplanes!




CHAPTER X.

THE CARRIER PIGEONS.


Billy and Henri, with much less weight to carry than their stalwart
fellow fugitives, and much spryer as sprinters, easily led in the race
to the flying machines.

Schneider stopped more than once in his tracks to fire from the hip at
the pursuing cavalrymen, but he failed to score a hit until the leader
of the troopers had almost ridden him down. One of the long-barreled
revolvers emptied the saddle of the rearing charger. Schneider had
thrown his rifle away at the last moment, finding his pistol more
effective in close quarters.

By this time, the boys, assisted by Roque, who was doing some shooting
himself, until all of the cartridges in the revolvers he carried were
exploded, had pushed and dragged the biplanes into the road, and ready
for the getaway.

Schneider, with a yell, hurled the empty revolvers in the direction of
the next comer, then bounded across the first ditch in his way, jammed
a shoulder against the now humming machine in which Henri was seated,
to give it starting impetus, and at the same instant leaped within the
machine.

Both machines were off in a jiffy, and when the cavalrymen in force
galloped to the spot, their carbines fell short of range. That they had
been chasing airmen was something of a surprise for if they had not
been so sure of a capture, the troopers would probably have pumped lead
much earlier in the chase.

"Guess he didn't get his man for keeps," remarked Billy to Roque, as a
side turn of the aircraft enabled him to look down on the field, where
a dismounted rider was getting a helping hand up from a comrade.

"Schneider gave him something to remember, anyhow," grimly replied
Roque.

In the other machine the red-topped and red-tempered aviator in the
observer's seat was deeply deploring, in no uncertain terms, the loss
of a crack-a-jack rifle and two up-to-date revolvers, borrowed for the
occasion.

"Hume may toss earth when I tell him his pet irons are gone, but it was
a shindy for quick action, and no saving grace."

Schneider evidently intended to tell the aviation lieutenant about the
fight before he mentioned the missing weapons.

The next flight planned by Roque was one of long distance--starting
twenty-four hours later, and leaving France.

"Good-bye, my young friends, and good luck to you; if you ever see
Colonel McCready again tell him 'here's looking at him.'"

These were the parting words of Colonel Muller, accompanied by a warm
hand-grip.

When the flying party finally reached Strassburg, the big German city
of the Alsace-Lorraine region, it was a glad day of halting.

They had floated in over a country literally shot to pieces by the
concentrated fire of the French and German guns--that is, in French
Lorraine--and in the distance viewed the great fortress of Metz. To the
aviators it appeared as though the land hereabouts had been devastated
by a gigantic earthquake, which had shaken down all the towns and
villages into a mass of shapeless, smoke-blackened ruins.

The boys wondered that they did not see more soldiers in the open, and
Henri expressed this wonder to his companion in the biplane.

"Oh, but the woods are full of them," assured Schneider, pointing to
the small columns of smoke rising here and there from the snow-clad
forests.

True it was that these same woods contained thousands and thousands
of armed warriors, ever on the lookout, who were gazing across the
frontier at the other woods, which concealed countless thousands of
soldiers of the Kaiser.

In Strassburg, Roque was again in touch with the invisible strands of
the far-spreading web he maintained. Among his first advices was the
most disturbing one that Ardelle had returned and had been making some
ten-strikes within the borders of the empire.

The boys shrewdly guessed that something of the sort had happened from
the renewal of the German agent's habit of charging almost every sort
of disaster to the secret work of his French rival.

Roque realized, as one of the profession, what an important factor is
the under-cover man who works within the enemy's lines in the service
of his country. And with a keen blade like Ardelle, big things were
possible, as past performances indicated.

But even Henri, as a self-claimed prophet, had no idea that the man
he knew as Anglin would bob up in Strassburg, though the city was as
likely a point as any in the war zone for secret service activity.

When Billy jokingly asked his chum if he had any predictions to fit
this occasion, Henri admitted that his second-sight "was off the job."

It soon developed that the secret service experts of both sides were
matching wits in this quarter. Reported in Roque's calendar of the
week was the giving away by one of his workers in hostile territory of
a French attack on the Germans during a fog, with the result that the
intended surprise resulted in a rout, and the assailing force mowed
down almost to a man. The mute testimony was in a low-lying valley out
in the Lorraine field--700 graves in a space 200 yards wide and about
50 broad.

Then a counter-move, wherein the French had advices from some source
unknown of the coming flight of a Zeppelin out of the Black Forest,
and three French aëroplanes were ready to charge at the big dirigible,
which, after a continuous exchange of fire lasting forty minutes, made
narrow escape to the north, just when the lighter craft had succeeded
in getting above it for a finishing stroke.

As it came about, and in a queer way, too, the boys were the first to
blunder upon a cunning ruse being resorted to by a smooth worker in
getting away information under the very nose of the astute Roque.

Billy and Henri, indulging their liking for high places, and having
a little leisure to look around, found a favorite perch in one of
the famous towers of Strassburg. They were interested, as airmen, in
watching the daily flying exhibit of the pigeons 'round about.

"Have you noticed, Henri, the streak of feathers every once in a
while that don't stop to associate with this housekeeping bunch? I've
seen two of these birds already this morning; they act just like an
aëroplane, circle about, and then break away like a bullet. There's one
now. Look!"

Henri followed the aim of Billy's finger, and, sure enough, a
long-tailed flyer was cutting the air like greased lightning in a
straight line west, without the slightest notice of the many of its
kind pluming themselves on neighboring towers and housetops.

"They make long visits," commented Billy; "I've watched, but never see
any of these air hustlers come back."

"That's funny," observed Henri, "let's borrow a glass this afternoon
and find out, if we can, where they start from. Why, this is good
sport; we'll be wearing badges next as pigeon detectives."

The boys had small notion then that they were butting into a real
business proposition, but one that did not advertise!

They were just curious to find out from where came the busy birds that
would not take time to visit with their brothers and sisters.

The most that the tower observers could discover, even with the field
glasses, borrowed without leave from Roque's traveling outfit, was
that the next bird comer took its bearings over a red-roofed building,
rising out of a circle of tall trees, a full mile to the east.

Had it so happened that Roque was in a social mood, and the boys making
him a confidant of their bird study diversion, there would, without
doubt, have been no delay in striking at the heart of the problem--and
everything else under that red roof.

Carrier pigeons were not beneath the notice of the big man with the
delicate touch!

But Roque was not inclined at the time to indulge in fireside fancies.
He was hooked up to a procession of events that needed constant
attention, and as it was all ground work for the present, he had no use
for aviators.

So he missed the first bang at the very musser-up of his plans whom he
was, day and night, seeking to locate.

"We'll amble out that way to-morrow and learn how to break pigeons of
the loafing habit."

Billy had once had a loft full of pouters in Bangor, that, he claimed,
ate their breakfast in bed!

"We'll shake Schneider and start early."

Schneider had been detailed by Roque to keep an eye on the boys, but
Henri felt sure that this firebrand would not be interested in pigeons,
save in a potpie, so he suggested the "shaking" process.

Trained in the sense of location by their aviation experience, the
boys proceeded without difficulty to the sparsely settled neighborhood
of the red-roof, which they found to be in the center of a neglected
garden, overgrown with weeds.

"Don't see any pigeon loft yet?"

Having been a fancier himself, Billy knew how the birds were housed.

"You might also say that you don't see any pigeons," added Henri.
"We've surely run by the station."

"Not on a little excursion like this," maintained Billy. "This is no
ghost story."

With the words he led the way up the long gravel walk extending from
the rusty iron gate to the front of the house.

"What will we tell them?" he asked, reaching for the brass knocker on
the dingy door of the dwelling.

"How will it do to say we are from the gas office?"

"A fool answer fits a fool's errand," agreed Billy as he gave the
knocker a sounding rap.

The pounding awakened no sign of life.

"Come on, Billy," urged Henri, "let's go. It's all a crazy move,
anyhow, and it was just because we were idle that we ever thought of
it."

"I'm going to try the back door," insisted Billy, "and then we'll quit."

There they got a response, probably after an advance inspection.
The door was partly opened by a bent, palsy-shaken old man, who in
quavering, high-pitched voice inquired their business. The question was
in French, and Henri responded:

"We just came out to look at your pigeons, and"--the age fell from the
figure in the doorway in the twinkling of an eye, two long arms shot
out, and in steely grip the astonished visitors were jerked inside, the
door closing with a slam behind them.

"What's the matter with you?" gasped Billy, whose collar had been given
a tight twist by quick-grasping, sinewy fingers.

Another violent wrench of the neck-joint was the rude form of answer.
Billy's fighting blood took fire, and he launched a kick at his
tormentor which sent the latter spinning, doubled-up, clear across the
entrance hall.

The jarred one, recovering his breath, leaped like a panther at the
Bangor boy, but Henri gave him the tripping foot, and he measured his
length on the dusty floor.

The boys were making a break for the door, when a new figure blocked
the way, suddenly emerging from a room nearby--a resolute fellow, with
a cold, gray stare, backing up a steadily leveled revolver.

"Been stirring up the monkeys, have you, Fred?"

The fallen man raised himself on his elbow and made the air blue for a
moment with his wrathful expressions.

"I'll fix you, you whelps," glaring at the sturdy youngsters who had
bested him.

"Stow the threats, Fred," advised the cool-head, who had restored the
pistol to his hip-pocket when he sized up the invaders as unarmed.

"What the devil brought you here?"

The newcomer put a snap in the question, but with no change of icy eye.

"What devil sent them here, you'd better ask?"

This suggestion from the battered Fred, who had again regained his feet.

"That will all come out under pressure," intimated the cool one. "As
long as you chose to honor us with a visit," he added with quiet irony,
"we must get properly acquainted. Show the young gentlemen into the
parlor, Fred."

Billy would have started a debate there and then had he not been, as
usual, stumped by the French language, which he only understood by fits
and starts. He knew for sure, though, that he was in Queer Street, with
this sudden shift from the regulation German talk he had been hearing
since landing in the empire. It was up to Henri to set matters straight.

Henri, however, had come to the conclusion that the pigeon story was
not popular here, considering its effect on the man who had first met
them at the door. So he wore a thinking cap on the way to the "parlor."

This apartment was the only one that had a living look, all the others,
noted in the passing, cheerless and empty. It was a "sky parlor,"
being reached by narrow stairway, only a garret between it and the
roof.

An old table, rickety chairs, portable cots and a rusty oil stove were
in evidence. There was a wide fireplace with no fire in it. It occurred
to Henri that the present occupants of the house did not approve of
smoking chimneys.

To get a line on what might be expected, he mildly inquired, with a
pale smile:

"Now that we are here, for what are we here?"

He was certain that he himself could not win a prize with the correct
answer.

The cold-eyed man could not restrain a short laugh in his throat.

"You are the fellow on the witness stand," he said, "but we must wait
for the prosecuting attorney to help us along."

In the waiting time the boys could hear through an open trap-door above
them the fluttering and cooing of a score or more slate-colored doves,
and it had just dawned upon Billy that there was some particular use
for the sheets of oiled tissue and skeins of pack-thread that littered
the table.




CHAPTER XI.

UNDER THE RED ROOF.


THERE were no additions to the party in the "sky parlor" until after
candlelight. The man called Fred was half-asleep on one of the cots,
when suddenly aroused by repeated knocking below. He made stealthy
descent, listened at the entrance for a moment, and apparently
satisfied with the signal conveyed in the rapping outside, cautiously
unbarred and opened the door. The person admitted did not come empty
handed, for when he stepped from the stair-landing into the upper room
he, and likewise Fred, were carrying market-baskets of goodly size.

"Hello, Gervais," was the hearty greeting he gave to the cool one,
the latter engaged, with a well-thumbed deck of cards, in a game of
solitaire.

"Hello yourself," returned the gamester, dropping the cards, and coming
forward to relieve the newcomer of the market basket.

Billy and Henri were seated in the shadow, beyond the range of the
candle rays, and at the time escaped notice. Both had started, however,
at the first sound of the new voice.

From a side view the make-up was that of a typical huckster of these
parts, fur cap, with ear lappets, corduroy greatcoat and cowhide boots.
Between cap and collar bunched a heavy growth of iron-gray whiskers.

The boys did not realize that their instinctive move, occasioned by a
certain tone in the voice, had not been amiss until the speaker had
turned full face.

Even the luxuriant whiskers could not wholly hide the Anglin smile!

Much to the astonishment of Gervais and Fred, and infinitely more to
the surprise of the imitation huckster, the boys at a single bound
jointly invaded the circle of light and grasped the elbows of their
one-time Calais acquaintance.

"What sort of a hold-up is this?" cried Anglin, in startled
recognition; "is it raining harumscarum aviators in Strassburg? By the
great horn spoon, it's enough to make me believe I've got 'em to see
you under this roof."

"I'll bet you knew that we blew in with Roque," proposed Billy, "for
you have a way of seeing seven ways for Sunday."

"You win, laddy-buck, on the first statement, but I'm still up a stump
on the proposition of how you got into this house."

"We were loafing," put in Henri, "started out on a pigeon hunt and got
the drag when we mentioned it at your back door."

"Pigeon hunt?" Anglin wore a puzzled look.

Henri made quick explanation of the whole affair.

"Ha! I see," exclaimed Anglin. "By the way, you did not happen to
mention your tower observations to anyone else, did you?"

This last query had a dead-earnest ring, with a rising note of anxiety.

"Not on your life," assured Henri; "in the first place, the big chief
had no time to bother with us; we had no inducement to talk to anybody
else, and, all in all, who'd have cared about the bird business,
anyhow?"

"Well, it seems there was one fellow who did."

Billy indicated Fred, who was unpacking the baskets.

"There are others," laughed Anglin, much relieved by the boys'
statement. Fur cap, wig and false whiskers were tossed onto the
mantelpiece, and the huckster was no more.

The baskets had produced a plentiful supply of ham, cold chicken,
and the like, and not one of the party could be charged with lack of
appetite.

In the glow of good-fellowship, Fred told Billy he was sorry that he
had given him so rough a reception.

"Honors are easy, old top," was Billy's jovial acceptance of the
apology, "and I am glad now that we did not break any of your ribs when
we banged you around."

"Say, Mr. Anglin, I am afraid, after all, that we may bring down
trouble on your head. I just know that Roque will be in a great stew
when he finds we are gone and will fairly comb the town to locate us."

The idea had begun to trouble Henri to the extent of spoiling the
pleasure of this reunion and indoor picnic.

"I have thought of this," admitted Anglin, "but the danger of discovery
is ever the same, and I don't believe this will either hurry or lessen
it. Besides, we are prepared, or, rather, had the way prepared for us,
to make a run on the slightest warning."

This restored to Henri happier thoughts, though he still held belief
that Anglin might have been safer if Roque had no special inducement to
immediately lead a searching party throughout the city.

That is just what happened, and it proved not an overly-difficult task
for the keen tracker to trace the boys to at least the vicinity of the
place where they were hidden.

The men under the red roof were soon made aware of the lurking danger
by the tooting of an automobile horn in the avenue bordering the
grounds north of the house.

It was a telegraph code set in shrill notes, and it was apparent that
Gervais, in alert listening attitude, had comprehended the message,
even as the motor-car sounded the final blast in its swift passage out
of sight and hearing.

The cool one, in most deliberate way, drawled the words: "Look out."

As effective as if a whole dictionary had been pumped through the
window by Anglin's scouts.

The chief calmly resumed the disguise of wig and whiskers, while Fred
blew out half-a-dozen candles with little waste of breath. With one
tallow dip still alight, and shaded by hand, the doorman then mounted
the ladder leading to the garret, thereby causing up there great
commotion in the pigeon roost.

When Fred reappeared at the foot of the ladder, it could be dimly seen,
he wore a broad grin and a wreath of cobwebs.

"When that flock arrives, empty-footed, old Winkelman will swear like a
pirate."

Fred had turned every carrier bird but one loose in the night. The
exception was fluttering in his hand, blinking its beady eyes at the
glimmer of the lone candle.

Anglin had seated himself at the table and was writing a few words on a
scrap of parchment, completing which he deftly attached the tiny roll
to the pink leg of the feathered envoy.

Fred lifted the window a few inches and released the bird.

With the utmost care every bit of paper, every inch of thread was
picked up and stowed away in the pockets of the three men preparing to
vacate.

Billy and Henri were busily figuring in their minds just how they were
going to come out of the scrape, when the creak of a shutter, under
prying force, was heard on the lower floor.

"They're here at last," muttered Gervais, dropping a hand to his hip,
on the revolver side.

Anglin laid a finger on his lips, enjoining silence, and tiptoed down
the stairway, the others following in shadowy procession.

On the first floor the leader paused. The attempt to force the firmly
hooked shutter had ceased, and no new form of attack was for the moment
in evidence. Anglin had removed his cowhide boots, and, with velvet
tread, then advanced the entire length of the long hall, motioning
those behind him to remain where they were.

He was back again in less than five minutes, and whispered:

"The house, I believe, is completely surrounded. They are waiting for
daylight, I suppose, to cinch some sure thing, the nature of which they
are not quite certain. If Roque is along and thought I was inside, axes
would have been working before this."

"They will find a lot here at daylight," chuckled Fred--"a lot of dust."

The party silently made their way through a side passage to what
appeared to have been intended as the dining and cooking domain.
Gervais had assumed the duties of guide, and he showed thorough
acquaintance with the premises by first producing a dark lantern from
a cupboard, and then moving directly to the black mouth of a steeply
inclined flight of stone steps descending far below the level.

The spacious cellar was divided into sections by partitions of solid
brick. But it was at the center of the foundation wall on the west
where Gervais halted.

"Give me a leg up."

Fred gave his comrade the required lift, and Gervais secured a
hand-grip on a big drain pipe that curved into the wall. He gave the
pipe a strong-arm-twist, and the bull's-eye shine of the lantern
revealed an aperture in the masonry, into which the climber squirmed.

Hardly had his feet disappeared, when he had turned about with his head
out of the hole in the wall and a hand down to help the next comer to
scale the space between the floor and the dislocated pipe.

Billy was given the hoist and crawled over the prostrate Gervais into
the narrow passage above; Henri quickly followed, then Anglin, and
finally Fred, who lent aid in pulling the pipe back to its moorings.

"'Snug as a bug in a rug,'" quoted Billy, who was really enjoying
this method of getting out of a tight place, even though getting into
another.

However, the rounded and cemented passage did not squeeze enough to be
uncomfortable, and there was steady draught of fresh air coming from
somewhere further ahead.

"The good man from whom you leased this property six months ago hardly
counted this as one of the improvements you agreed to make," remarked
Anglin as they started to wriggle through the drain.

Gervais laughed. "I didn't do anything to the pipe but what had to be
done, and 'a stitch in time saves nine.'"

"It is likely to save three that I know of," grunted Fred.

"You can always count on Gervais to think for the future."

The man so complimented by his chief said nothing, saving his energy
for the vigorous use of hands and knees necessary to make progress in
the smooth channel.

The journey on all fours ended at a heavy grating, through which faint
daylight was peeping. Through the barred opening the outlook was into a
deep ravine, with a small stream coursing at the bottom, and a dense
growth of small timber and bushes rising to the level on all sides.

Directly opposite the entrance of the drain, in a small clearing on
the high ground across the gully, the broad windows of a stone cottage
reflected the glare of the slowly rising sun.

"There is nothing else to do, my friends, but to lay low until brother
Roque completes the scouring of this section. We are well on the way
but not yet out of the woods, as the saying is."

This was the view of the chief, and his views were seldom questioned.

It was a rather gloomy prospect, this crouching wait in quarters so
confined, but the secret service men counted nothing a hardship, and
the boys had to possess themselves in patience.

The capacious pockets of the huckster's greatcoat, with which Anglin
had not parted, despite its weight, in the long crawl, contained a
supply of food, taken from the baskets before starting.

From the avenue that lay between the ravine and the grounds about the
house which they had recently quitted, the cramped company in the drain
could hear the rumble of traffic, and once they heard voices in close
proximity to their hiding place.

"Giving them something to puzzle about, eh, Gervais?"

"Rather a fuddle for them, chief," agreed the cool one, "and the best
of it all, they don't know whom they're after, unless it be these
youngsters."

"Oh, I propose that the boys shall be found in due time, but the
balance of us will keep dodging to the best of our ability."

"Some ability, too, believe me, boss," was Billy's contribution.

"Well, I believe we can hold our own," complacently observed Fred.

With the wearing of the long day, the prospect of liberation eased the
trial of the later hours. As night fell apace, the first greeting to it
was the glow of a lamp in one of the windows of the stone cottage.

Gervais moved close to the grating, and fixed intent gaze upon this
illumination. In the course of a half-hour his vigilance was rewarded
by a sight that he evidently anticipated. Somebody was repeatedly
crossing and recrossing the patch of light, now and then deliberately
standing in front of the lamp. That "somebody" was making dots and
dashes as plain as day to the trained vision of the receiving expert.

"The coast is clear," he announced.

A little pressure and the bars were down.

Out into the night crept the weary five, with the luxurious experience
of once more standing erect and having a good stretch.

Having replaced the grating in the drain entrance to a nicety, Gervais
led the way down the steep slope of the ravine to the creek, which
Billy and Henri attempted to drink dry, so great was their thirst.

"Now is a time when the best of friends must part," said Anglin. "I
have been thinking it over, and the suggestion is that you, my young
friends, must be relieved of any suspicion of willingly associating
with suspicious characters. Gervais, Fred and I have our mission
clearly mapped, the cause we serve is supreme, and the safeguarding I
propose is of mutual benefit. With you boys here we can have no open
acquaintance, and of us, as we are, you must claim no memory. To be
brief, you have been detained by rough characters at the other end of
town, and you will be there discovered at the roadside in the morning
bound and gagged and stripped of all your possessions."

"I am afraid we are mighty poor picking," joked Billy, "but it is all
right to give us the truss up, as we brought this shake-up to your
door."

"That is neither here nor there now," consoled Anglin; "we must mend
the situation as best we can."

And so it came about, at a point remote from the red roof, a passing
policeman picked up two much hunted boys who were decidedly the worse
for wear.




CHAPTER XII.

THROUGH FIRE AND FOG.


"YOU'RE a pretty pair, I must say."

True it was, the boys were not fixed for any dress parade when they
first faced Roque, immediately after their delivery to the secret
agent by the police authorities. The crawl through the drain pipe and
the additional effort to give them the appearance of real victims of
violent treatment, had served to convert the usually natty and trim
youngsters into a couple of quite disreputable looking characters.

It is quite likely that Roque would there and then have put the
returned wanderers through the "third degree" of questioning had it
not been for a fortunate and welcome interruption in the shape of a
messenger, who could not be denied, and who, it proved, brought tidings
that wholly changed the line of thought of the stern chief.

"Take these chimney-sweeps to the tub and the clothesline," he gruffly
ordered, and Schneider, half concealing a broad grin, accepted the
service with celerity.

"You ought to have heard the boss when he found that you had not
reported at quarters last night," said the red-topped aviator, when the
trio were out of Roque's hearing. "He took the wind out of my sails, I
tell you, and I am not considered slow in the cussing business."

"Where were you, anyhow?"

"In the hands of brigands, of course," gravely advised Billy, with a
wink at Henri.

Schneider was so possessed with the prospect of some new and exciting
move by Roque, indicated by the manner of the chief upon receipt of
the message a few minutes before, that he did not burden the boys by
forcing evasive explanations of their mysterious absence.

"If Roque had half a suspicion that we had been in company with his pet
enemy, the prince of slyboots," confided Henri, when the chums were
alone, "our joint name would be Dennis."

"Gee! If that fellow hadn't bumped in just at the right time, I think
we both could have claimed the title of Ananias!"

Billy was a poor hand as a dodger of truth, and much relieved to escape
the witness stand in this instance.

The kind of danger with which the boys best loved to toy was again
speedily coming to them--the peril of aëroplaning.

Schneider brought the order to report forthwith at the aërodrome.

At the aërodrome an immense Zeppelin airship, as long as an ocean
liner, had just been inflated. Roque was engaged in conversation
with the captain of the great dirigible when Schneider and his young
companions reached the grounds. The pilot of the huge craft and his
assistants had already taken their places in the front gondola, the
foremost end of which had been screened for their protection, and
it was evident that sailing time was near. When the master mariner
had exchanged a parting word with the secret agent he entered his
room in the central cabin of the Zeppelin, which was in telephonic
communication with the front and rear gondolas and other parts of the
ship. In the meantime, Schneider had instructed the boys to give the
No. 3's an inspection to see if the attendant helpers had properly
prepared the machines for a long journey.

The young aviators then surmised that they were to travel as convoys of
the monarch of the air, which even then was majestically rising.

Roque hastened to the machine in which Billy was already seated and
waved a signal to the waiting Henri in the other biplane, containing
also the redoubtable Schneider.

The swift flyers easily overcame the slight lead of the big ship,
though it was making 40 knots, and took up the guiding positions. The
flight was directly away from Lorraine and historic Strassburg.

"I wonder if our huckster friend is in the crowd back there?" was a
mental question with Billy.

It was many a day before the young air pilot had a chance to again meet
Anglin.

When this journey ended it was in territory remote from that of any
former experience of the Aëroplane Scouts--a new battle landscape.
It had snowed, and the drab, brown plain of Poland had turned to
glistening white. The biplanes floated in a tarnished silver sky,
which, pressing down, seemed hardly higher than a gray ceiling. The
aviators landed on the clay bank of the winding yellow river, the
Bzura, within 400 paces of the German trenches. Gun answered gun across
the golden stream, shell on shell spattered into the soft earth, and
rifles rattled unceasingly.

Schneider sniffed the powder smoke like a seasoned warhorse. "It's the
life!" he exclaimed.

"And the death," added Roque.

He knew that men lay bleeding and broken on the banks of this yellow
streak in the white picture.

"You're just right, boss," murmured Billy, nodding his hooded head,
"the war map looks all red to me."

Roque, as usual, wherever he went or wherever he was, seemed to carry
an Aladdin magic carpet on which to sail, for in the next flight of the
biplanes a few miles distant he found a bright spot in this winter
scene of rack and ruin--a clean, white lodgekeeper's kitchen, where a
canary sang, and where the aërial wayfarers rested and were fed.

"I'll show you even better," he said, "when we break into Warsaw."

The chief also had a particular crow to pick with the defenders of
the Polish capital. One of his men, for some time operating with the
Russians, had been detected, and the end of a story of brilliant secret
service achievement was marked by a little mound of earth in a Warsaw
stable yard.

But for the present there were busy days ahead for the aviators in
reconnoitering the Russian lines.

Most of the aërial work here was over a plain, flat as a floor. Black
dots here and there marked isolated houses, and the Kalish road was
bordered by a line of leafless trees with smooth trunks, which reminded
the young pilots of a rank of grenadiers.

"What's that bunch over there?" queried Billy, nodding toward a group
of horsemen, shrouded in long caftans, wearing lambskin caps shaped
like a cornucopia, and bearing lances.

"They are Cossacks," replied Roque, from the observer's perch, "the
strange fighters who never surrender."

Billy had later an opportunity for closer view of these reckless riders
in the service of the Czar.

The flyers could see that the road below was this day crowded with the
carts of refugees, trailing in endless procession, on the top of each
vehicle the members of the family, the average one man to five women.
The boys noted that there were not so many children here as they had
seen among the homeless wanderers in Belgium. The same problem was
here, however--what are they going to do?

"There they go again," cried Henri, referring to renewed outbreak
from the long gray noses sticking out over the top of a brown gun
emplacement--belching cones of death, and shooting red flare into the
gray-white atmosphere. Then another noise out of the winter-worn copse
of trees--pop, pop, pop, the notes of rifle fire, all raising a queer
mist over the plain. With all this racketing no soldier could be seen
at the point of fire.

If trouble was contagious, the biplane Henri was driving suddenly
caught some of it; something went wrong with the motors, and it was
a case of get down quick in the long slide, in which performance the
young pilot excelled. He landed safely enough, but without choice of
place.

The machine was stranded in Sochaezev, a city of the dead. Pale faces
were still peering from some of the doors and windows, though almost
every roof had been battered in, leaving only the stringers, reminding
one of skeletons.

Billy had instantly volplaned in pursuit of the disabled biplane of his
partner, and the two experts, assisted by Schneider, were speedily at
the work of repair.

Roque impatiently moved about among the ruins, acting as a sentinel,
and occasionally turning to the laboring aviators with muttered
insistence for haste.

"Hist!"

With the chief's sibilant warning the boys softly laid down the tools
and motor parts they were handling, and stood at attention. Schneider
drew a revolver from his belt.

Roque, in crouching attitude, held an ear close to the frozen earth
surface, and the others took example.

"There's a cavalry troop headed this way," hoarsely whispered
Schneider. The pounding of many hoofs, growing louder and louder, was a
sound apparent to each listener.

Then as a new diversion, out in the open field to the right of the
road, down which the horsemen were galloping, rang out the rapid blows
of pikes and spades on the ice-covered soil.

"They're throwing up kneeling trenches."

Schneider had a true ear for war moves.

The grating noise of the closing of a gun breech preceded a tense
moment.

By the shifting of sound it was impressed upon the listeners that the
oncoming cavalry had left the road and had swung into the plain on the
left.

"We'll be between two fires in a minute or so."

This from Roque, as he rejoined his companions standing by the
aëroplanes.

"Give us a precious ten minutes and we need not care," volunteered
Henri, who had discovered the defect in the machinery which had brought
them down.

"Get at it, then," urged Roque.

The boys did "get at it" so vigorously that they raised a perspiration,
despite the frigid air.

"It's all right now," triumphantly announced Billy, hastily repacking
the tools.

That they had been spared the time required to meet the emergency was
due to the fact that the cavalrymen had diverted their course so as to
make a sudden frontal charge on the artillerymen from the cover of the
ruins.

"Now for a move backward," ordered Roque in low tone; "even though
the gunners to the right may wear the gray we would have no show for
recognition if we bounced up like a flock of partridges."

So the aviation party cautiously wheeled the biplanes in the deserted
street as far as they could from the supposed line of the coming clash.

None too soon were they out of range, for with savage yells the
Cossacks rode full-tilt from cover at the German guns and gunners in
the shallow trenches.

Amidst the roar of desperate conflict the biplanes whizzed away like
great arrows.

"Some speedy tinkering we did in that ghost town, Mr. Roque?"

"Nothing slow," assented Roque, leaning forward to give Billy a pat on
the back.

"Where away now?" asked the pilot.

"Back to the lodge for the night," directed the chief.

No such comfort for the boys in the next flight.

They were booked for a journey to Przemysl, the vast underground
fortress of Galicia, about which the Russian right end was then
snapping like the tip of a whip around a sapling, and later surrounded
on all sides by the Muscovite forces.

While viewing the first back-wash of the Austrian forces from the high
tide of Russian invasion, the aviators had hurtled through a maelstrom
of noise. The yells and shoutings of wagon drivers, the rattling of
thousands of wheels over stony roads, the clatter of horses' feet made
an indescribable tumult, and to this were added the sounds of infantry
fighting.

Roque had reliable advices during one of the stops in the flight that
the fortress defenders were still holding their own, and no Russian
charge had as yet crossed the barbed wire mazes that circled the city.

Never since the memorable race at Friedrichshaven had the No. 3 type
of biplane attained such velocity as in the finish of this forced run
to the Galician stronghold, the final dash over the black-plowed farms
through a wet fog and under fire of a Russian battery posted in the
hills.

"I feel like I had been hauled through the lower regions by a
nightmare," complained Billy, as he later sat with Roque, Schneider and
his chum in the Steiber Coffee house.

"I will say," confessed Schneider, "that I never hit the wind so hard
before in my flying experience. My eyes must look like two burned holes
in a blanket."

"I might say, Schneider," remarked Roque, "that if it had not been for
that timely fog you would have hit the ground harder than you ever did
before. Those gunners on the hill could not have missed us if given
fair sight."

"It has just occurred to me that they came pretty close, anyhow."

"They sure did, Buddy," laughed Billy, following this assertion by his
chum. "I almost collided with a shell that sounded like a dozen factory
whistles. By the way, Mr. Roque," he continued, "it looks like you were
tied up here for some time to come. I don't see any way out of it."

"Do not lose any sleep over that problem, young man; if we got in we
can get out. You ought to know by this time that there is always a
hole in the air that cannot be blocked."

"You bet he's right," exclaimed Schneider, slapping his knee for
emphasis.

"Hustle for bed, all of you, and stay there until you are called."

With this the chief faced the fire and lighted one of his big, black
cigars. He had some thinking to do.

The boys were awakened the next morning by gunfire.

"Oh, lawsy," sleepily murmured Billy, "is there another battle started
already?"

Schneider at the first report had gone on his bare feet to the nearest
window.

"Nix, fellows," he cried, after short observation, "they're not
shooting at men this time, it's wild geese they're popping at."

The besieged garrison was adding to its store of eatables by bringing
down wildfowl, which flew in abundance over the town.

"Let me in on that."

Henri owned the idea that he was something of a full hand as a Nimrod.

A voice in the doorway: "You will be 'let in' on bigger game than that."

Roque smiled at the youthful enthusiast, and added:

"There is a man's size job for a half-sized man waiting until you shake
the sleep out of your system."

"Get up, you snowbirds, and sing for your salt."




CHAPTER XIII.

CAPTURED BY COSSACKS.


"COLONEL, permit me to present a likely pair of air travelers who are
never satisfied with the ground space they occupy."

Billy and Henri tipped their caps to six-feet-three of superb manhood,
in Austrian uniform of dark blue.

Roque made the introduction, and the boys felt quite sure that this
ceremony only completed advance notice of the character of service they
were capable of rendering.

The officer, measuring the young aviators with a keen gray eye, nodded
approbation.

"They will admirably fit in the carrying service," he remarked
to Roque; "they are jockey weight, which is a good point for the
assignment."

Billy assumed from the manner, if not the language used, that Henri and
himself had successfully passed inspection.

It appeared that airmen here were persons of some importance, as
affording the only connecting link with the outside world.

Almost every day, the boys were advised, an aëroplane went to
Galician headquarters, on the outward flight carrying only letters
and postcards, but on the return trip bringing tinned meats and hand
grenades for the soldiers.

The big biplane piloted by Billy and Henri dwarfed anything else in the
way of air machines shown in the fortress.

Other aviators, viewing the No. 3's, cheerfully conceded that they were
certainly built to be winners.

These experts, however, as usual with their kind just getting
acquainted with our boys, were inclined to be doubtful of the capacity
of the youngsters to rank with themselves as drivers of aircraft.

It was up to time--a little time--to convince them of their error of
judgment.

The crack driver of the Przemysl air squadron, Stanislaws, which name
Billy promptly shortened to "Stanny," was the earliest convert to the
new belief when he went as observer with the boy from Bangor on the
latter's first foraging detail.

Lack of knowledge of the country prevented the chums from working
together at this period.

"He will show me the way, but just hazard a little guess that I'll have
a little show of my own on the way."

Billy buzzed this in the ear of the grinning Schneider, when the order
to get away was received.

Henri, with the comfort that his turn was coming, stoutly backed the
belief that his partner intended to exceed the speed limit as a lesson
to the doubters.

"'Stanny' will have a new kink in his whiskers before he gets back,"
was the expression, to be exact, used by Henri on this evening.

The great bird machine, soaring like an albatross in the northern sky,
soon vanished from the view of the watchers in the fortifications.

"He's six horses and a wagon with a dog under it," Stanislaws earnestly
advised the officers at army headquarters, pointing at Billy, who was
reducing heat in the propeller by liberal use of the oil can.

"Stanny" had already made good with the American boy, not so much by
his frank expression of admiration for the youngster's handling of
the military biplane as for the reason that the Austrian talked plain
United States when they were alone. Billy was dead-set against the
trial of eternally groping for the meaning of foreign phrases.

"Do you know why we aviators are running a freight line just now?"
queried this new friend.

Billy acknowledged that he had not the least idea on that subject.
"Why?"

"Filimonoff."

"Who in the dickens is Filimonoff?"

"He is the greatest of all Cossacks," explained the senior airman,
"and the very devil on two sticks. Near Przemysl, not long ago, he
held up one of our convoys and captured 200 wagons of grain and coal.
He strikes where least expected, plays the peasant to perfection and
secretly gets a lot of information that does not belong to him. It
would be worth a lot to a fellow who dulled the spurs of this cock of
the walk."

"Ah hum," thought Billy, "I can pretty near guess now what brought
Roque to this neck of the woods."

So long was the enforced wait at headquarters this day that it was not
until after nightfall that the biplane set out on its return voyage to
the fortress.

A strong air current from the north, with a decided snap to it,
forced the aviators out of fixed course, but despite the biting blast
Stanislaws was yet able to advise the pilot as to the general direction
to be pursued.

They saw ahead of them a red glow and the uplift of a spreading
fountain of sparks. It was a house burning to the ground, probably
fired by a Russian shell.

The blaze revealed a familiar landmark to the biplane observer. "Keep
her nose to the left," he advised the pilot.

Billy, who figured the speed fully 70 miles to the hour, had the
machine under perfect control, and it instantly responded to every
shift of the steering lever. With the ordered slight turn it was
scarce ten minutes before the biplane hovered over the vast, shadowy
mass of the fortress below. The powerful propeller stopped, and the
winged racer stood still against the black dome of the midnight sky.
Now the forward plane dipped as the throbbing of the motor again was
heard, and the bird machine plunged down at an angle of 45 degrees,
settling in the plaza within the silvery ring formed by its own
searchlight.

"The work of an artist," proclaimed Stanislaws to the aviators in the
night watch.

"Carrying some weight, too," added the soldier who superintended the
removal of the cargo.

Billy had a bedtime story for Henri about Filimonoff.

It having been determined to regularly use both biplanes in the
carrying service, the detail at last put the boys together in the same
machine, with Stanislaws and Schneider manning the other.

"None of your self-made adventures," Roque admonished, when he had
informed Billy and Henri of the arrangement.

The young aviators were, in duty bound, compelled to mumble some sort
of assurance that they would stick closely to the task set for them.

That they failed to keep the agreement proved, strange to say, the
fault of Schneider, the very man charged to keep an eye on them.

It was the third aërial expedition of the week, and following the same
route, without mishap, had no longer the charm of novelty to Billy and
Henri, and, it may be stated, the easy sailing had begun, also, to
pall on the high-strung warrior with the sorrel hair, now sitting as
observer behind the Austrian pilot.

At army headquarters, Stanislaws was giving his entire time and
attention to checking up the needs of the garrison, and figuring
closely on the capacity of the biplanes to carry all that he deemed
absolutely necessary to take back to the fortress on this particular
return journey.

The balance of the crew--the trio who were getting weary of the
uneventful freight business--had nothing special to do but wait.

"No use of sitting still and twiddling our thumbs; I don't see any harm
in looking around a bit."

Schneider's suggestion appealed to his companions, and they had no
trouble in securing the loan of a pony each from the large number of
these hardy specimens of horseflesh browsing around the camp.

They were advised by a good-natured member of the commissary department
not to venture too far beyond the line of patrols, and Stanislaws gave
them to understand that he expected to be ready to start within the
next three hours.

"We'll be here on time all right, Stanny," called Billy, clucking his
pony into a smart canter, following the lead of his similarly mounted
friends.

The one who was left behind had no reckoning then that he need not have
hurried in his packing.

The roads traversed by the riders were deep in slush and mud because of
a thaw, but the fresh ponies reveled in the going, and it was not long
before a tempting range of harder ground extended the gallop further
afield.

"Say, boys," suddenly remarked Schneider, rising in the stirrups for a
survey of their whereabouts, "I think we have gone about far enough,
and must take the back-track immediately."

"Wait a moment," urged Henri, "there's a man waving to us over there."

Schneider, looking in the direction indicated by the boy at his side,
saw it was a peasant who was making the friendly motions to attract
their attention.

"What's the word, my friend?"

The peasant spread out his hands in gesture of cordial yet humble
greeting. "My house is near" (pointing eastward over the plain). "It is
yours."

"The sun is yet high, let's go over and see the house of his nobs,"
gayly proposed Billy.

The native shrugged his shoulders, and wore a puzzled look at the words
in a tongue evidently foreign to him.

Henri supplied the information in German, it being the language in
which the invitation had been extended to them.

"I think he could understand even better if we were talking Russ, but
still, as he made a fair stagger in German, we will have to let it go
at that. We can see him home, as he says it is near, and then strike
out for headquarters."

Prodding his shaggy steed with his heavy boot-heels, the stranger
showed the path to his guests, the party speedily reaching a small but
solidly built farmhouse on the bank of a small river.

Schneider, with soldierly precaution, transferred the heavy service
revolver he carried in his belt to a convenient pocket under the cape
of his overcoat.

Perhaps the husky fighter felt it was not much of an exhibit of courage
to set a gun at hand when he found that no other human than this old
farmer with a crook in his back seemed to inhabit the premises.

"I was as dry as a fish," asserted Billy, eagerly accepting a drink of
cold water from a stone mug proffered by their host. There were other
thirsty ones in the party, for the mug was emptied several times in the
passing.

Just about that time Schneider lost all interest in water. Happening to
glance out of a window facing to the north, his eye caught a sunflash
on a lance-head, and now and again other sparkling tips.

The revolver he now appreciated was in the right place.

But of what avail, after all, was one pistol against a band of reckless
and wily Cossacks, if such were under those nine-foot lances?

Billy and Henri were unarmed.

The peasant was up with a jump when Schneider proclaimed his discovery
of impending peril.

"Hide! Hide!"

With the words of alarm he tugged at an iron ring in the center of the
heavily-planked floor.

It was considerable of a lift, this weighty trap-door, but the old man
developed a surprising degree of activity and strength, and quickly
presented the way to a cellar by means of a ladder, the length of which
indicated considerable depth.

"Not for me," strenuously objected Schneider; "they will never catch us
like rats in a trap."

"Quick! Quick!" pleaded the peasant.

Billy, at the window, excitedly announced:

"They're the real thing; I can tell by their caps and caftans. The
Cossacks are here!"

Schneider was as cool as a cucumber--that was the way the near prospect
of a death struggle always affected him. He was hot-headed only when
given the smaller provocations.

"Bar that door!"

The boys hastened to obey that crisp command.

The old peasant attempted to leave the house before the entrance
barrier was secured and fastened.

"Halt!"

An unwavering line of steel barrel, and the menace of the voice behind
it, checked stockstill this attempt to escape.

Fully a dozen of the rough riders of the north had dismounted in the
farm enclosure, and advanced upon the house, some with lances and
others carrying curved swords without guards.

"Get away from the windows," hissed Schneider, himself backing against
the wall. "You too," savagely addressing the peasant, who in the past
few moments continued to show remarkable recovery from the infirmity of
bent shoulders and halting step. The man nervously fingered the folds
of his rusty green tunic as he obeyed the fiercely given command, and
as he stood nearest to Billy the latter was inclined to keep at least
the corner of his eye peeled on the suspect. It was well for Schneider
that the boy was watchful, for when the supposed farmer stealthily
lowered his hand it grasped the bone haft of a dagger.

The Cossacks outside vigorously pounded the door with lance butt and
sword hilt, and receiving no response to their peremptory summons, set
powerful shoulders to work. But they could not budge or even shake the
solid barrier.

Then at the window appeared a bearded face of ferocious type,
surmounted by high-crowned lambskin cap.

Schneider slowly raised his revolver.

The transformed peasant, noting the action, crouched like a panther for
a spring, which he made the same instant. But the murderous intent was
baffled and the leap fell short.

Billy Barry's foot was purposely in the way, and the would-be dagger
wielder hit the floor with a crash. Startled by the tumble, Schneider's
trigger-finger caused the waste of one revolver shot, and spoiled
further attempt to deceive by silence.

In the moment of excitement no thought had been given by the defenders
to the rear of the house, and before Schneider could even turn on his
heel, a half-dozen lance points threatened him, front and back.

The fallen peasant was on his feet in a flash, and it was a mighty ugly
look that he fixed on Billy.

"You will go to the cellar now, because I say it, and will come out
again if I will it."

The sign of leadership was on the man, for none of the strange soldiery
about him ventured to speak even a word in his presence.

Schneider, disarmed and no longer resisting, was hustled into the dark
hole in the floor, and the boys were forcibly assisted in the same
gloomy descent.

The heavy trap was closed with a bang, and sealed by the crossing of a
clanking chain.




CHAPTER XIV.

A WONDERFUL RESCUE.


"BLAMED if I oughtn't to be treated for the simples."

Schneider was, indeed, a dejected figure at the foot of the long ladder
in this inky well, the only point of light being a porthole sort of
window, set high in one of the four stone walls.

"We're all of the same name as chumps," echoed Billy.

The situation certainly had serious aspect to the prisoners. While they
had considerable confidence in the trailing ability of Roque, here was
a case with about every chance in the world against successful tracing.

An isolated farmhouse, far from the beaten track, not even in present
line of military operations, and confinement practically in a granite
tomb, from which no wail of distress could possibly be heard outside.

What fate the Cossacks had fixed for them was merely a matter of
dreadful surmise.

"Slow starvation," was Henri's unhappy guess.

"Penned up in this den until we go mad," was the blood-chilling view of
Schneider.

"Say, you fellows give me the creeps."

Billy wanted his troubles one at a time.

The next one was all too near.

While feeling his way around the rocky walls, Schneider settled in his
tracks as though he had been shot.

"Don't you hear water splashing?" For confirmation he stared blankly at
the boys who had not as yet strayed away from the ladder.

"Are you starting your madhouse already?" demanded Billy.

"But there is water running near," insisted Schneider. "Come over here,
if you don't believe it."

As if to humor their friend, the boys joined him.

Sure enough, the lapping sound was plainly audible at this point.

Further ahead in the dim recesses of the cellar the sound was of
dripping, a steady patter like rain.

"Maybe they have pulled a sluice between here and the river," suggested
Henri.

"The fiends," muttered Schneider.

"Gee!" exclaimed Billy, starting back from a forward step or two, "the
floor is filling!"

Stealing along, inch by inch, the water spread throughout the cellar.

The prisoners retreated to the foot of the ladder and sought perches on
the rungs. In case of full flood they could stave off drowning for a
time by climbing higher. It was the only way.

"It's a pretty tight place we're in, old man, but not for the first
time, and, mind you, we have always pulled out somehow."

Billy was ever ready to pass a cheering word to his chum when cheering
words were most needed.

Schneider's nerve was again in the ascendant, he having sufficiently
abused his lack of horse sense in being so easily led into such a trap.

"If I had hold of a good steel pike for a bit of an hour, there is
nothing like a few planks that would keep us down here."

"Yes, or a couple of axes, or a stick of dynamite, or an electric
torch, and so forth," bantered Billy.

While Schneider and Billy were word sparring to keep up their spirits,
Henri noticed that the water on the cellar floor had pooled in the
sunken spots, indicating that the pressure from without, for the time
being, had largely subsided.

"No need for life belts yet," he cried, "the river isn't going to come
through."

"And, thanks to that blessed streak of light," Billy pointing to the
bull's-eye window, "we're able to see that you are right. So much for a
starter."

"We'll beat you yet."

Schneider shook his fist at some invisible foe on the other side of the
ceiling.

When, however, the first flush of encouragement at the fading of the
flood had dimmed, it seemed a small matter about which to rejoice.
The situation appeared as hopeless as before to the imprisoned
aviators. With the coming of night the one diamond in the sable setting
vanished--no ray of light to slightly relieve a condition now of
absolute blindness.

"Oh, for one more glorious chance to meet those dastards in the open,"
groaned Schneider, who again was overwhelmed with keen regret that he
had surrendered at all in the first place. But then he had no idea of
such a dungeon as this, and, too, he had feared to provoke instant
death for his young comrades.

In the coming dismal hours the troubled trio, deserting their ladder
perches, stretched their aching bones upon the slimy floor, and passed
the night in uneasy slumber.

Henri was the first to awaken, and as a morning exercise essayed to
reach the little window by working hand and toe as a means of scaling
the rough surface of the wall. As he clung for a fleeting moment to
a protruding stone his chief discovery through the aperture was that
outside it was raining in torrents.

Perhaps not much satisfaction in return for sadly torn fingernails and
considerable waste of already waning energy, yet it was some assurance
that they were not intended victims of a drowning plot of man's
conception.

"It's not the river that is feeding this drip," announced the climber
to his companions in misery, "it's raining like fury and the water
coming in here is the gutter fall through these rocks."

"A bally lot of moisture," growled Schneider, splashing ankle-deep
across the cellar to inspect a swinging shelf which had just caught his
eye.

He reached up, and presently turned, holding at arm's length a mouldy
sailcloth bag.

"Hidden treasure," whooped Billy. "Bring it nearer the light,
Schneider."

The treasure proved to be meal of some sort in a fair state of
preservation. A tasting test demonstrated that here was something that
would at least dull the gnawing pains of hunger, when mixed with water,
of which latter there was more than a plenty.

"We might make a fire out of the shelf," suggested Henri, "and turn
this stuff into hot cakes. I've got a few matches in my pocket."

"I see a picture of the fire you could make down here," exclaimed
Billy. "But what's the matter with trying it out on the trap door? Burn
our way out."

The speaker had taken on an air of excitement at the prospect.

Alas! The matches in Henri's possession had been carried on his
sleeping side, the side all night in contact with the slimy floor.
There was not a strike in one of them.

Schneider, inveterate smoker that he was, remembered that his pipe,
tobacco and match-case were all in the pocket of his great coat, of
which the Cossacks had divested him after capture.

So in silence the unfortunate three mouthed the soaked meal, bitterly
disappointed that they could not realize upon Billy's brilliant idea.

From bad to worse, they did realize, and soon, upon a much less
desirable development. The rain had no stop this time to reduce the
water flow into the cellar. In restoring the meal sack to the shelf for
safekeeping, Schneider's long boots were wetted to the knees, and there
was nothing to do but mount the ladder, and stay there.

To save a fall when napping, the prisoners lengthened their belts and
buckled themselves each to a rung above the one upon which he sat.

"While you were wishing awhile ago, Schneider, why didn't you wish for
a boat?"

"You'd joke on the way to the scaffold, young man," said the subdued
firebrand, fixing a reproachful look on Billy.

"Never say die," retorted the irrepressible youth.

Another wearing night, and in Schneider's next trip for the meal bag
his hip boots were none too long in the matter of preventing his taking
on a cargo of water.

But this third day of desperate contemplation was destined to be
marked by an incident which resulted in the lifting of the weight
of gloom--and the herald of light and liberation from an apparently
hopeless imprisonment was four-footed.

A few lines now in backward trend, to tell about the ambulance dogs,
as many as a thousand, renowned for their excellent service for the
Germans in both the eastern and western theaters of war. Each of
the sanitary companies has attached to it four of these dogs, the
German shepherd breed, marvelously trained and fitted for work on
the battlefield, commanding everywhere eloquent tribute for their
remarkable performances in finding the wounded and their acute scent on
any trail.

Stanislaws had long completed his packing of the biplanes, and many a
time and oft had impatiently paced Commissary Square, as many times
going to the military road upon which he had last seen his aviation
comrades riding joyously away. "'Stanny' was in a stew," as Billy would
have put it, and he was not averse to letting anyone about him know it.

When night came word was passed from patrol to patrol, and back again,
and no definite report of the missing aviators.

An observer was secured from among the young officers in the camp, and
Stanislaws himself piloted one of the biplanes on the return journey to
the fortress.

Roque was immediately advised of the mysterious disappearance of his
three followers, and promptly indulged in some very emphatic comments
not appropriate for parlor use.

"You must fly again in an hour," he raged, "and I'll be with you."

Stanislaws, though weary and nerve-strained through the exertions of
the long flight just concluded and by the weight of anxiety, would not
listen to the offer of brother aviators to relieve him of the added
exertion of repeating such a journey without rest.

"I'm going back with him," he stoutly maintained--and he did.

At headquarters Roque took advantage of the first glimpse of daylight
to institute work of inquiry, in which practice he was conceded to
be without equal. But to no avail. The furthest outpost had seen the
riders pass, and, fully satisfied with their credentials, had paid no
further attention to their movements.

Somewhere out on the boundless plain, alive or dead, were the three so
earnestly and expertly sought for.

"It's a hard nut to crack," Roque stated to a group of officers, "but
I have opened just such hulls before, and I am not ready yet to plead
inefficiency."

"Perhaps they have fallen into the hands of the enemy," said one of the
officers.

"I can hardly believe that an old campaigner like Schneider would run
into the lines of the foe with his eyes open. If suddenly attacked by
lurking prowlers, I'll warrant we'll find some sign, for I know the man
too well to believe he would be taken without a struggle and somebody
biting the dust."

Roque had evidently not figured on Schneider's present handicap in the
shape of the boys, forcing discretion ahead of valor.

Then the winning thought flashed into the mind of the secret agent--put
the ambulance dogs on the trail!

The reminder was the approach of one of the sanitary officers. The
latter, when he was told of the situation, at first presented a
doubtful front.

"The heavy rains out there," said he, indicating the plain by a
sweeping movement, "have drowned the scent, even if we had a good lead
from this point; but," he concluded, noting the disappointment in the
face of Roque, "I do not mind making a try for it. Here, Blitz."

The splendid animal bounded to the side of his master, lifting
expressive eyes, and indulging in a series of short barks, showing
readiness to serve in the best dog language.

Hasten, dog, there is sore need for aid in a dark place of yonder sea
of mud!

Schneider, Billy and Henri had not ventured from the ladder since the
early move after the meal-bag, which the first named had decided to
keep within reach, and save further wading to the shelf. The flood on
the floor showed no sign of receding--indeed, the trio had twice been
compelled within the hour to climb a little higher to escape the splash
at their feet.

Schneider, anything for diversion, pounded on the trapdoor until his
knuckles were a bleeding mass, shouting until he was hoarse.

"What's the use?" he dully questioned, settling again into an attitude
of sullen indifference.

The boys set up a duet, but with discord so apparent, even to
themselves, that they quit the singing attempt as a matter of
self-defense.

This noise had hardly ceased, when Schneider poked his head around the
ladder support on the side of the light, with a hand hollowed behind
his ear.

"Jumping jingo; listen!"

They all heard at once the snuffing of a dog, and with the sight of its
black head stuck into the bull's-eye window, Billy dropped into the
flood, breast deep, and struck out for the wall, up which he swarmed,
regardless of scrape or strain.

He had seen the ambulance dogs in camp, and knew of the breed and
their doings. Holding onto the narrow ledge like grim death with one
hand, he used the other and his teeth in tearing out the scarlet lining
from his cap, which he twisted around the dog's collar band. Blitz--for
Blitz it was--whined his receipt for the red token, backed from the
aperture, and padded away like the wind.

Two hours later the trap was lifted, and the exhausted survivors of
this desperate adventure were hauled into daylight, joyfully greeted
by a goodly company, including Roque. Stanislaws, sanitary officers,
pioneers, and last, but not least, Blitz, tugging at the line by which
he led the rescue party to the scene of his original discovery.




CHAPTER XV.

DUEL TO THE DEATH.


SCHNEIDER was a very walking furnace, with his burning desire to meet
again, on equal footing, any individual of the Cossack band that had
thrust him, lamblike, into the stone tomb under the farmhouse, and,
particularly, the fake peasant for whose wiles he had so foolishly
fallen.

"Give us a biplane hunt for that gang," he importuned Roque, "or I will
never get the red out of my eyes. Filimonoff himself might have been in
the crowd, for all I know, and you ought to be doing some tall bidding
for his headdress. It was just like one of his tricks."

The firebrand felt that he had hit the mark with the last part of his
heated argument. Roque would have counted full reward for the chase in
the bagging alone of the wily chieftain of the strange horsemen.

He turned to Stanislaws, remarking: "You men for awhile will have to
resume the use of your own machines in the carrying service. I have
concluded to give Schneider a chance to retrieve his blunder and return
a lesson that will stick into savage hides."

"We won't stand in the way for a minute," quickly and earnestly
stated the Austrian flyer, "and more power to you, sir. What's
more," he added, "we can spare an aëroplane or two, and I know
several full-blooded lads who would be mighty willing to join such an
excursion."

"Meaning that you are one of the volunteers," rejoined Roque. "How
about it, Schneider?"

"It is hitting the nail on the head," heartily approved the brick-top
warrior, "Stanislaws, Breckens, Bishoff, and Mendell--there's two crews
that would help some."

"What's the matter with us?"

The Aëroplane Scouts had edged into the circle. The idea of a biplane
hunt especially appealed to them.

"Sure you're going," proclaimed Schneider, glancing first at Roque for
sign of assent, which was given by a nod.

Four military biplanes twelve hours hence lay in readiness to start
for the Cossack roundup. The Austrians in the party carried a supply
of bombs for emergency work, but the most elaborately armed of all was
Schneider, in the rôle of chief challenger. He bristled with revolvers,
a shoulder-hung carbine and a heavy cavalry saber.

"If you should have a fall, old fellow," laughed Stanislaws, "it would
sound like a barrel of tinware rolling down a mountain."

"Never you mind," said the one-man arsenal, "I have a job of making
sieves on hand."

The plan was to hover for a time in the vicinity of the farm where
Schneider and the boys had been held up, or, rather, down, and if no
sight of the Cossack company, to reconnoiter still further north.

The flyers were given a great send-off by the soldiers at headquarters.

"Just like a balloon ascension at a county fair," observed Billy, as he
took his place as pilot in front of Roque.

"Something new here, I see," Henri calling the attention of his
aviation companion Schneider, to the fact that Stanislaws had provided
telephone helmets for each of the crews, whereby pilot and observer
could communicate with one another without yelling their heads off,
receivers over the ears and a transmitter close to the mouth.

"This will save my voice for singing," jollied Henri.

Schneider, remembering the vocal effort in the cellar, came back with
the expression of hope that the telephone invention would not serve to
that extent.

"Oh, but you are a jealous cuss," declared the boy, as he guided the
machine upward, in compliance with the signal given to all by Roque.

"We have all the advantage this time,"'phoned Billy to Roque, when the
flight was well under way; "if the outfit below is too heavy for us we
can stay out of reach; if we feel that we can lick them, a dive will
settle the question--our choice both ways."

For the first few miles all the creeping figures below were of the
friendly forces, but with the onrush of the aëroplanes all traces of
the camp were obliterated and only a trackless waste presented itself
to the view of the lofty travelers.

Directly, Schneider reported to his pilot that the farm enclosure was
just ahead, with its yellow ribbon border, which the river wound around
it.

The observers on the four biplanes gave the premises a thorough looking
over with their glasses, but had no announcement to make of any human
movement below.

Separating the machines, each distant from the other several hundred
yards, the pilots guided northward, at reduced speed, and within a few
hundred feet from the ground.

Some twenty miles forward, the little fleet encountered a snowstorm,
and the earth was already covered with a dazzling white carpet.

A range of hills forced a higher flying altitude, and in an atmosphere
growing decidedly chilly. The aviators were quickly compelled to close
their coats at the throat, and to huddle down in the protecting folds
of their service blankets.

On a high level, Roque instructed Billy to make a stop, so that the
long sitting airmen might work the cramp out of their joints by a
brisk runabout. The snow had little depth on the wind-swept plateau,
and landing could be made with smooth certainty.

A spot of blackened surface showed bare through the powdery snow
covering, indicating a recent campfire there.

"Trot out the coffee pot," Henri called to Schneider, "here are the
makings of a blaze."

The recent heavy rains had filled with water the rocky basins near at
hand, and the thin skim of ice now forming thereover was easily broken.

The Austrians elected tea as their special inspiration on the occasion,
and the rival fumes soon ascended from the spouts of coffee and teapots.

As the sky above was now clearing, from the elevation the aviators
could see the brown and white summits of other hills, divided by valley
cuttings, as far as the eye could reach.

Schneider was just about to light his beloved briar pipe, when all of
a sudden he dropped the ember he was lifting to the bowl, and pointed
toward the high ground edging the opposite side of an intervening gulch
to the right of their bivouac.

A solitary horseman had ridden into view, and both rider and steed
posed, statue-like, on the verge of the steeply descending slope.

Roque like a flash covered the smouldering fire with a blanket,
checking tell-tale spirals of smoke.

Fixing a glass on the equestrian, Stanislaws uttered the one
word--"Cossack."

"He's our meat," snapped Schneider.

"It's your first go this time," reluctantly conceded Stanislaws, who
was himself aching to draw first blood.

Schneider, taking general consent for granted, gave Henri a nod
sidewise, and both moved as quickly as they could on all fours to their
biplane. While the boy was getting the motors in play, the fighting
observer shifted his carbine from shoulder to knee.

The buzzing of the aëroplane had evidently caught the ear of the wild
cavalryman across the gulch, for the horse was rearing, lifted by an
unexpected wrench of the bit.

Nothing, however, on four legs or two, would have a ghost of a chance
to outdistance a racing aëroplane.

Spur as he would, the horseman was overhauled in the space of three
minutes.

The aëroplane, skimming the earth, mixed its scattering of snow
particles with those raised by the pounding hoofs of the wildly
galloping horse.

So close together were pursuer and pursued, that the Cossack's first
lance thrust came within a hairline of reaching the ribs of Schneider,
leaning forward in preparation to make a flying leap from the aircraft
when it should lessen speed sufficiently to enable him to keep his
feet when alighting on the stony soil.

Why the observer did not immediately use carbine or revolver in return
for the lance attack, queerly impressed the young pilot ahead, who,
naturally, would expect such action on the part of his armed companion,
gravely menaced by a wicked weapon too lengthy to be successfully
resisted by counter strokes of a saber.

Henri's second thought was that Schneider had been touched in a vital
spot by the steel point, and that he, too, would next get into the deal
of death. To send the machine aloft was a third thought, following
in a flash, but the execution of this purpose was as quickly delayed
by a motion indicating a lift of weight behind. Schneider had jumped
from the biplane, now wheeling the ground, and within two lengths of a
precipice, hitherto unobserved.

The Cossack, on the very brink of this dizzy declivity, had jerked his
horse to its haunches, at the same moment when Henri checked further
movement of the biplane by a skillful side turn.

"It's you and me for it now," roared Schneider, "and the devil take the
quitter!"

Turning in his saddle, the Cossack, desperately at bay, accepted the
challenge with ferocious alacrity, backing the fiery animal he bestrode
and taking to foot with drawn sword.

Henri saw that it was the same man who in the guise of a peasant had
played them such a scurvy trick--the same, but yet seeming hardly
possible, viewing this upstanding, powerful specimen of a hardy,
unconquerable race.

Schneider, never forgetting a face, had known the impersonator at the
first glance, which added to the incentive of wiping out the score
created by the Cossack company at the farmhouse down on the plain.

Noting that his adversary was armed only with sword and dagger, having
blunted his lance against the armored side of the biplane, the aviation
firebrand discarded his carbine and pistol, tossing them one by one
onto the snow carpet. He had the notion of settling this affair in a
manner that would completely retrieve certain prestige of which he
conceived himself to be the loser.

In the meantime, the balance of the aviation party swooped down upon
this level, and leaving their biplanes, advanced to the scene of the
impending duel.

"Keep back, all of you," shouted Schneider, the bloodlust gleaming
from his eyes; "it is one to one here, and though he put twenty to one
against me, I will give him his chance, and take mine."

"Better humor him," suggested Stanislaws in an aside to Roque, "he will
never rest easy if he does not get rid of the black mark he has rubbed
on his own nose."

"He may get a red mark or two in this combat," grimly observed Roque,
"but let them fight it out. Schneider ought to be able to take care of
himself."

Billy and Henri followed with fascinated gaze the movements of their
champion, who, though he sized up almost half a head shorter than his
extremely tall antagonist, was all wire and a swordsman without equal
in the estimation of the Heidelberg student body.

The duelists indulged in no time-saving tactics. Schneider rushed his
man from the outset, but every rapid lunge of his heavy saber found
clashing counter from the curved and guardless steel in the practiced
hand of the wily Cossack.

Forward and back, ever fiercely fencing, the sworn foes panted defiance
at one another, and each with blasting words renewed efforts to strike
a death blow.

"Oh!" Billy had seen blood dripping from Schneider's left sleeve, and
leaving a tiny trail of carmine splotches in the trampled snow. In
agony of apprehension, the boy again fairly shouted: "Don't let him
down you, Schneider; look out for the next!"

Roque gave the excited lad a muttered order to hold his tongue.

"Ha!" This from Stanislaws. A scarlet seam crossed the forehead of the
Cossack, and he wavered for a second, as if partially blinded. Only
for a second, though, did his sword arm hesitate. Schneider received
another wound, this time close to the throat.

"He's done for," tremulously whispered Henri, wondering why the soldier
onlookers did not interfere, and eager to make a saving move himself.

Then, as though a whole row of wine glasses had been riven by a knife
stroke, the Cossack's blade, cleft near the haft by a biting downward
cut of the saber, fell tinkling at his feet.

This was the last flare of Schneider's waning strength, of which,
however, the Cossack was apparently unaware. He did not wait to meet an
expected heart thrust from the victor.

With a piercing yell, he turned, waved the sword stump about his head,
and leaped far out into the void before him.

Schneider, on hand and knee, game, but all in, as the saying is,
mournfully shook his head, and faintly murmured: "He would have had
another chance to finish."

Stanislaws, something of a surgeon, stanched the blood welling from
the wounds of his comrade, applied bandages, and soon had the fallen
fighter on his feet.

The Cossack's mount had disappeared, a fact first noticed by the acute
Roque. "Mark you," he predicted, "that riderless horse will be sure to
stir up a wasps' nest, and somebody here will get stung if we attempt
to hold this position. Schneider's punctures are enough for one day."

Roque's prediction was a sure shot, for he had hardly ceased speaking
when a score or more of horsemen charged from the cover of a rocky
defile and bore down in force upon the aviation party.

"To your places!" thundered Roque.

The pilots of the several aëroplanes were already making ready for
hurried flight, and Henri, in addition, had assisted the wounded and
weakened Schneider to his seat in their machine.

Breckens, Bishoff and Mendell emptied their carbines and revolvers in
the direction of the oncoming lancers, clearing a saddle or two, and
swung into the rigging of the waiting biplanes just in time to permit a
clean getaway.

Right over the brink of the precipice the start was made--it had to
be the quickest way--and a thousand feet of ascent gained without an
upturn.

Circling about on high the soldier-observers scattered the horsemen on
the plateau with a shower of bombs.

Schneider had had his innings, and returned in full measure all that
was owing.




CHAPTER XVI.

DRAWN FROM THE DEPTHS.


"WELL, Mr. Roque, if you did not get Filimonoff this trip, you struck
mighty close to him, for I'll warrant the man whom Schneider vanquished
was a leader in the Cossack horde."

"And something of a fighter, you might add, Stanislaws," rejoined the
secret agent. "But there's another day, and the kingpin and I may yet
lock horns."

The aviation party was again at Galician headquarters, and the
interesting invalid, Schneider, was already declaring that he was as
good as ever.

Roque had a grouch, chafing because of the delay of the Austrian forces
in getting through to the relief of Przemysl.

"Just think what might be done if we had enough flying machines,
Zeppelins and aëroplanes, to bring over an army corps every week or
so." This idea expressed by the ever-enthusiastic Stanislaws.

"You are not talking airship now, Stanny; it's an air castle you have
in mind."

This pleasantry on the part of Billy turned the laugh on the Austrian
aviator, in which he joined himself.

"There's one thing sure," finally declared Roque, "I know of at least
two airships that are soon to sail over the heads of the Russians who
are now blocking the way to the fortress."

"I just knew he would be pushing something across before long," said
Henri to his chum.

"From the way he looked at us when he spoke, it's safe to believe that
we will be somewhere behind the push."

Billy had a hunch that his job was secure whenever Roque had work above
ground.

Schneider had heard enough to set him at the task of cleaning and
polishing his personal stock of firearms.

The four biplanes returned that very night to the besieged fortress,
from which two of the machines were destined to leave in short order on
a most important and perilous journey.

Our boys had instructions to give the aircraft a thorough going over,
fill the petrol tanks to utmost capacity, and carry all the condensed
foodstuff possible.

"Maybe he is figuring on a chance of a lay-up in the mountains,"
suggested Stanislaws, detailed to assist the younger aviators in the
work of preparation.

"'Maybe' is a good word to use in connection with the moves of the
chief, for you can't prove anything by us."

The present was all that counted with the busy lads, hustling to
complete their immediate assignment.

"Ready and waiting," they soon announced to the chief, who simply
nodded approval, and went on with the work in which he was
engaged--studying and making field maps.

Henri put in the spare time afforded with continuous instruction of
his chum in the German language, Billy having already acquired, by
hard knocks, talking knowledge of French. They were thus occupied one
morning, when Schneider appeared, in war-like array, with brief order.

"Buckle up."

Roque found everything in shipshape for the getaway, and smiled at the
impatience of Schneider, who had been stamping around the hangars since
the first glimpse of daylight.

While the young pilots were drawing to the elbows their fleece-lined
gauntlets, the secret agent was earnestly assuring the commander of
the garrison of his belief that the way would very soon open for the
long-expected relieving force.

"I think I can advise them to good effect if we get through in safety,"
he said, mounting his perch in the biplane, and giving Billy the word
to go.

As the biplanes shot through space, only Roque, the directing power,
had knowledge of their destination, though Schneider inferred that the
finish would be somewhere in the thick of battle.

This inference was not far amiss, for when the aircraft finally
slackened speed, and stood still against the blue vault of heaven,
still as the condor floating above his native mountains, the aviators
looked down upon a thick forest of bayonets, shown on all sides by the
square formation of the Austrian forces, then endeavoring to pierce the
Russian front near Lupkow and thus relieve Przemysl.

"We are in the Carpathians," Schneider advised his flying mate.

The fighting in these mountains had then been continuous and intense
for weeks, the two armies contending desperately for the ridges,
the possession of which would give advantage to the holders. Every
concession of a few yards of the rocky slopes had exacted heavy toll of
lives.

Behind the Austrian lines at Lupkow the aviators made landing,
descending through a sea of smoke, and amid deafening roar of furious
conflict.

Roque had hasty conference with the commanding officers, and outlined
conditions at the great underground fortress, to save which this day's
engagement had been planned.

Schneider and the boys had received orders from their chief to stand by
the aëroplanes, and on no account to leave their posts.

"He evidently does not believe there is much of a show of smashing the
Russian barrier to-day," observed the firebrand, who little relished
the infliction of standing still in the rear while so much powder was
being burned in front.

It was soon apparent, the way the tide of battle was turning, that the
rear of the Austrian position would not be such a lonesome place after
all. Retreat had begun, and immediately Roque emerged from the ruck.

"This isn't our day," was the news he brought; "get under way or you
will get under foot."

It was a stirring scene that spread under the rising biplanes, the
massed formation attacks of the Austrians hurled back again and again
by the sheer weight of the Russians, pouring men forward in seemingly
unending numbers.

"They're thicker than flies in Egypt," growled Schneider, when his
soldierly eye perceived that the Austrians could no longer stand the
pressure of the numbers arrayed against them, and that the day was lost.

The aviators decided to adopt the manner of the eagle and nest high
that night. They found a level on a mountain peak not very far removed
from the clouds.

"You could cut the stillness up here with a knife," asserted Billy, and
his companions agreed that there was a decided difference between the
shell-rent territory from which they had just flown and the awesome
silence of this sublime height.

"It might also be mentioned that the cold on this top could be sawed
into chunks," put in Henri, taking the precaution of covering the motor
tanks with blankets.

Schneider volunteered to skirmish for some material with which to
establish a campfire, while the boys busied themselves in opening some
of the tins enclosing the food supply.

Roque found consolation in keeping alight a long black cigar.

Presently he concluded to follow in the footsteps of the wood hunter,
and hasten the prospect of a cheery blaze by the time night should fall.

With the passing of an hour or more, and no sign of the fuel seekers,
Billy and Henri developed an uneasy streak, rendered more acute by the
drear surroundings and the oppressive lack of all sound.

"We had better do some scouting; I'll go daffy with this waiting
business."

"I'm with you, Billy," joined in Henri, "anything but sitting 'round
here doing nothing."

The boys lost no time in picking their way through the rocks in the
direction taken by their absent companions.

"Let's give them a shout," suggested Billy, himself acting first on the
suggestion.

No answer to the shouters, when they paused at intervals, hoping for
the welcome response.

Stumbling along, careless now of bumps and bruises, the lads so often
raised their voices to high pitch that they were hoarse from the effort.

Rounding a huge boulder that blocked their path, Billy, who was
in the lead, suddenly started back with a cry of alarm, and Henri
instinctively threw his arms about the waist of his chum.

Lucky move, this, for the Bangor boy was in the closest kind of way
connected with a mass of crumbling earth that swept with a slight
rumble into the darksome depths of Uzsok pass.

Henri's strong pull landed both boys on their backs--but on the safe
side of the boulder.

"Narrow shave that, old boy," murmured Billy, raising himself on his
elbow, and reaching for the hand of his chum, "and it's to you that I
owe----"

"No more of that," interrupted Henri, "it's only a rare occasion when
you were not doing something for me. I think we can account now for
the disappearance of Roque and Schneider. It completely unnerves me,
though, to believe that our companions are lost in this abyss."

Billy was on his feet in an instant, alert and resourceful.

"There's a way of finding out whether or not they are down there, and
we will never quit searching as long as there's a speck of hope."

Gingerly skirting the boulder, he found solid ground on the higher
side, to the right of the treacherous spot on which he had so narrowly
escaped a long fall.

Stretched out full length at the verge of the steep descent, Billy
peered into the depths, giving vent to several ear-splitting whoops in
rapid succession.

A faint halloo finally came back from the dim recesses of the pass.

"Glory be!" cried the strenuous hailer, "there is somebody below--and
that somebody is alive!" Through the hollow of his hands Billy shouted
words of encouragement to the unseen owner of the voice answering from
the bush-grown wall of the chasm.

"It's a clear drop of twenty feet, and smooth as a billiard ball before
the growth begins and the rocks shelve out," Billy advised his chum,
the latter to the rear and maintaining a firm grip on the ankles of the
venturesome prober of the pass mystery.

"Oh, for an hour more of daylight," lamented Billy, as dusk began to
envelop the lonely mountain. "Gee! Why didn't I think of it before?"
Imbued with his new idea, he quickly swung around, bounced to his feet,
hauled Henri up by the wrists, and triumphantly demanded:

"What's the matter with flying around there in the machine?"

"But it's getting too dark now to see anything in that hole," objected
Henri.

"Where's your wits, Buddy? What do we carry searchlights for?"

"I sure am a woodenpate," admitted Henri, using a fist to tap his
forehead; "let's go to the biplane as fast as our legs will carry us."

The boys raced like mad for camp.

With every light available from both machines set in one of the
biplanes, fore and aft, the young aviators sailed through the shadows,
got their bearings from the big rock and fearlessly swooped into the
lower strata.

The glittering gondola of the air trailed a line of illumination along
the rugged face of the chasm wall, but in the first passing, Henri, as
observed, gave no signal of discovery.

The insistent hum of the motors prevented the hearing of any hail that
might be given from without, and as effectually drowned any call from
within the machine.

"Another round, Billy boy," shouted Henri, "a little lower down."

The next circle and come-back brought results, attested by a gleeful
hurrah from the observer.

"There's a man on the ledge over there--there's two, by jingo! Round
again, pard. Steady now!"

The aëroplane was dangerously near the ledge, a little above it.
Henri was standing, one hand gripping a stay for balance, and in the
other grasping a ball of whipcord. With a sharp turn the pilot nosed
away, the tail lights of the machine gleamed full for an instant upon
the dark figures silhouetted on the rock face, and in that precious,
fleeting instant, with a round arm swing, Henri sent the cord ball,
unwinding as it dropped, straight down upon the ledge.

"Up!" sang out the maker of the successful throw, and as the biplane
made almost perpendicular ascent, it tugged, kite like, at a long line
of cord, paid out by one of the men left behind on the rocky shelf.

Once out of the canyon, the pilot checked his flight at the first
level, and both boys, under the glare of the searchlight, speedily
spliced and knotted two coils of fine-fibered rope, part of the flying
equipment.

Henri, leaning over the edge, drew the cord connection taut, indicating
to the holders below that all was ready at the top. The boy felt sure
that Roque would understand--for it was Roque he had seen in the circle
of light when the ball was thrown.

Sure enough, the cord was drawn downward, and the rope followed the
cord, with, happily, plenty to spare for the making of a safe and
secure anchorage.

"Roque is something of a sailor, as we know, and he'll come up all
right, with a good purchase for his feet against the wall. As for
Schneider, the three of us can hoist him, if necessary."

Billy's advance arrangement went somewhat awry, for it was Schneider's
red top showing first in the light over the brink, and Roque was the
one hauled, almost a dead weight, to solid ground and safety at the end
of the swaying rope, looped under his armpits.

The secret agent's right hand rested in an improvised handkerchief
sling, and his face was set in the pallor of pain.

But how strangely gentle had grown the piercing fixity of those
hard-speaking eyes when turned upon the rescuers who had dared so much
in a feat wonderful to record in aviation annals.

"You might have waited until daylight," he chided, his voice freighted
with emotion, "and with less risk to yourselves."

"And the morning found a couple of maniacs cavorting around this
wilderness. No, sir, the rest cure wouldn't have been the right
prescription for us. Eh, Henri?"

"He's as right as a trivet, Mr. Roque; we took the proper tonic,"
assured Henri.

"A man's size swallow for all that," was Schneider's amen.




CHAPTER XVII.

A MIGHTY STONE ROLLER.


CAREFUL examination revealed that Roque's injury was not of broken
bones, but a severe sprain, due to the twisting suspension from the
bush which had checked his fall. Schneider had gone down feet foremost,
breaking through the growth until he struck the ledge.

"I didn't expect Mr. Roque so soon," he said, with a face-wide grin,
"but I knew him by his legs, and gave him an open-arm reception."

"Until Schneider reached for me," related the secret agent, "I thought
there was nothing underneath but the bottom of nowhere. It was
certainly a curious accident, all in all, the two of us tumbling as we
did, stopping in the very same place, and both of us alive to tell it."

"There was mighty near a good third on your peculiar track," interposed
Henri, "for Billy had set his heels for that very slide which you two
took."

"If it had not been for Henri," asserted Billy, "there is no telling
how deep I would have gone."

"And if it had not been for both of you, there was hardly more to look
for than a miserable end for Schneider and me. We could have proceeded
neither up nor down, for there was nothing to put hand or toe into for
many rods either way."

Roque did not propose that the boys should lose any of their dues for
gallant achievement by other belief than that two lives had actually
depended upon their prowess.

When Schneider intimated that he thought it was time for another
attempt to find material for a fire, there were two young rebels
emphatically against the proposition.

"We'll move where there is wood in sight," was the joint declaration.

Roque agreed that a change of base was desirable, and a flight from the
mountain top was in immediate order.

As the machines descended and followed a lower course, ghastly
reminders of the struggle that had recently taken place in and
along the pass were easily discernible from the lookout seat of the
biplanes--the melting snow on the slopes revealing many bodies of
Austrians and Russians.

In a clearing at the edge of a considerable forest the aëroplanes again
settled, the observers being first convinced that there was no military
occupation, especially hostile, of the wooded tract.

"This beats the mountain roost a mile and a half," declared Billy, the
leader in hopping out of the aircraft.

In a big hole in the ground, dug by the impact of a cannon ball,
Schneider started a brush fire, and in a few minutes was passing hot
coffee around.

"I must say," observed Roque, between bites at a sandwich of corned
beef and hardtack, "that I don't seem to be getting anywhere on this
trip except into pitfalls. All this is sheer waste of time. I had hoped
to see a relief march to Przemysl begun within a day, but here we are
tied in a knot, and not a step forward."

"Well," consoled Schneider, "you gave them the route that could be won
with the least difficulty."

"But what's the good of that when the opening wedge couldn't be
driven?" impatiently queried Roque.

Schneider scratched his head. He had no answer.

"There is one thing sure," exclaimed the secret agent, "and that is, I
must be on the move, for this isn't the only fish scorching in the pan."

Billy just then edged into the conversation. He had made an alarming
discovery. The petrol supply in the biplane tanks was at low mark. The
aviators had expected to replenish long before this, and the disaster
at Lupkow had spoiled their last chance.

"Oil nearly out, sir," were the words that brought Roque to his feet
like a jumping-jack.

"The devil you say!"

Here was a quandary that completely upset the chief.

"We ought to have filled day before yesterday," explained Billy, "but
you know why we didn't."

"The only thing to do that I see," advanced Henri, "is to add the
supply of one machine to that of the other, and two of us hunt for the
new camp of the Austrians."

"They could fix us all right," assured Schneider, "for there is quite a
number of aëroplanes with the force which was driven back."

"It was my intent to get in touch once more with this corps, but it was
not my intent to divide this party in the going. It cannot be helped,
though, and it may take but a few hours at most. You are sure" (turning
to Billy) "that you cannot raise enough power for both motors to go the
distance?"

"I fear, sir, that both machines would be stranded in less than an
hour; and, with all this uncertainty as to how far we would have
to go, there is no telling into what kind of place and under what
circumstances we would be compelled to drop. There would be much less
odds against the one-machine plan."

"It's up to you to prove it," challenged Roque, "for you and I are
going to make the trial."

The transfer of the petrol accomplished, Schneider and Henri were left
in sole possession of the camp in the woods, after a last strained
look at the departing biplane, a little blot on the sky, finally
dissolving in the mist of the mountain top.

"Let's knock about a bit," said Schneider, suiting action to the words
by starting up the nearest slope, where the gloomy pines were farther
apart than in the dense growth below.

"Ah! Here's where the Russians must have gotten a severe jolt. See
here, my young friend"--Schneider pointing at a scattered ground array
of discarded rifles, knapsacks, sheepskin coats, and many caisson
shells in baskets. "Not so very long ago, either, for you will notice
that all this is on the top of the snow and not under it. You can
safely wager that here, and at this season, it is not very long between
snows."

Here and there were other objects, stiff and stark, that sent a shudder
up Henri's spine.

Picking their way still higher to the apex of the ridge, the man and
boy had view of a land depression, bowl shaped, almost cleared of snow
by exposure to the sun, being free of shade or shadow.

Something on the far side of the bowl, catching a golden ray from
above, glittered like a big diamond. Henri called Schneider's attention
to the flashing point.

"Worth a walk across," conceded the soldier-aviator, moving that way.
Henri, interest aroused, made it a point to outpace his companion.

Drawing nearer, the investigators saw, in half-sitting posture, back
against a blanket roll, a soldier--in dark-blue uniform, Austrian
infantry--marked by emblems of rank, including a sparkling decoration
on the breast.

A silver flask lay close by, alongside of sword and belt.

Schneider dropped to his knees, seized one of the nerveless hands
of the officer, and fingered the pulse of the lifted wrist. The old
campaigner had noted that the blood curdle in a tunic fold was yet
unfrozen.

"Hand me that flask."

Henri quickly complied with his comrade's request, first unscrewing the
metal top. Schneider tenderly moved the head of the officer to his own
shoulder and poured the contents of the flask through the livid lips.

"He lives!" cried Schneider.

The evidence was a faint flutter of the eyelids, a twitching of fingers
and labored breathing.

Henri unrolled the blanket that served as a backrest, made a pillow of
the wounded soldier's knapsack, and Schneider shifted his burden to
this new resting place.

It was not long until the vigorous first aid rendered by the aviators
found a more marked response--the heretofore unconscious officer looked
up at the anxious faces of the workers, and perceptibly smiled through
the beard that concealed his mouth.

He had comprehended that he did not owe a Russian for the help that had
come to him in this extremity.

Schneider addressed him in the familiar tongue of the Fatherland, and
Henri also added a word of sympathy and encouragement in the same
tongue, at the time bending his head in the hope of a word in reply.

That word was spoken, and others in faltering train.

"He says his name is Schwimmer, Johann Schwimmer--captain."

"A captain without a regiment," was Schneider's sad comment, his eyes
bending further afield, where corpses in blue, in heaps and singly,
marked the path of deadly artillery practice.

"It does look as if we are caring for the only survivor," said Henri,
realizing that Schneider's mournful observation was founded upon fact.

That Captain Schwimmer understood what was passing between his rescuers
was manifest, for stoic though he was, he covered his eyes with a
trembling hand and his breast heaved convulsively.

At the moment there was a startling diversion--the whip-like crack of
rifles from the opposite edge of the bowl, at the very point where the
aviators had stood when first attracted by the shining point on the
captain's tunic.

Spat, spat--bullets boring the earth close to the right, left, and at
the very feet of the trio on the ridge.

Schneider, again a firebrand without sentiment, coolly unslung the
carbine from his shoulder, and put a shot across that evidently
counted, for it raised a death-yell.

Without further ado, the soldier-airman plumped down on the ground,
with his back to the sufferer on the blanket, and hoisted upon his
broad shoulders the sorely wounded soldier, who faintly protested, and
urged Schneider not to so hamper himself.

But you might as well argue with the wind; the sorrel-top warrior was
up and away, making little of his load, Henri sprinting at his heels.

The firing company of Russians, either stragglers from the rear of
a corps or scouts in advance of one, had evidently no intention of
permitting the escape of several prospective prisoners, and they took
up the chase as eagerly as the sporting pursuers of a deer, whooping
and shooting as they bounded in a body across the separating hollow.

But for the good start made, Schneider could not have possibly,
extra-weighted as he was, maintained speed enough to have gained even
the base of the mountain for which he was heading. As it resulted, the
carrier and the carried had hardly reached the first level, some fifty
feet up, when the Muscovite marksmen were in close target range, and
a leaden pellet among the many flattening against the rocks clipped
the visor of Henri's cap as he cast a last look at the oncoming crowd
before climbing like a squirrel into the rocky shelter above.

Schneider had placed Captain Schwimmer out of any possible line of fire
from below, and was doing some return shooting on his own account.
Unluckily for this style of defense, all of the surplus ammunition was
in the locker of the biplane back in the woods, and the few rounds in
the aviator's pockets were soon exhausted.

Henri knew that such was the situation by the fervid remarks of his
companion.

But such was the angle of the aviators' perch that there could be no
attack except from the front, and even that was a climbing approach.

It occurred to Henri, considering the lay of the land, that lead was
not the only effective substance with which to repel boarders.

The ground was loaded with natural ammunition--loose rocks and rocks,
thousands of them, from fist size up to a ton.

"Hey, old scout," hailed the boy, "give them a dose of dornicks."

Schneider took the hint with a burst of approbation.

"Two heads are better than one," he facetiously declared, hauling off
his greatcoat for greater freedom as a heaver.

A dozen or more of the pursuing party were working up the acute
elevation when the first huge stone thundered down the incline. The
boulder made as clean a sweep as a well-placed ball in a bunch of
ninepins.

"A ten-strike!" whooped Schneider. "Set 'em up again in the other
alley!"

The Russians back-tracked for a time, finding a better range to fire
at the defenders on the mountainside, and such was the fusillade that
Schneider and Henri were compelled to stay in cover to save their skins.

"They can't work that game, though, to support a scaling force," said
Schneider, "for the same fire would catch the scalers. If they come any
nearer we can fix them, all right. But what a mercy it is that they
haven't a field gun with them."

"As it is, we can't stave them off very long," added Henri. "When it
gets dark the stone-rolling game won't work."

"Let me tell you, young man, when that hour comes, all they'll find
here will be an empty nest."

The veteran had a moving plan up his sleeve, and the chief reason he
had for making this stand was to give the injured captain a little more
time to mend.

A scalp wound was what had laid the officer low, and since recovering
consciousness he had rallied remarkably. In the soldier's knapsack,
which Henri had thoughtfully carried, notwithstanding the hasty
leave-taking, was three days' rations, and the invalid had also been
strengthened by the food his new friends prevailed upon him to swallow.

During the day Schneider several times checked an effort of their foes
to reach the height by starting a little avalanche of rocks at the
critical moment.

In the periods of enforced peace, he cast an eye about for a likely way
for quick retreat.

The way presented itself in the shape of a fallen pine that bridged
a narrow pass, deeply dividing this isolated level from the mountain
chain that widely extended back of the occupied position, and rose in
serried crags to the very skyline.

It was a nerve-testing prospect, alluring alone to a professional rope
walker.

"We'll tackle it in short order," resolutely declared Schneider, after
final survey.




CHAPTER XVIII.

TRAILS THAT CROSSED.


WHEN the biplane bearing Chief Roque and Billy Barry cleared the
mountain top, the pilot and observer had a fixed understanding that
every Russian camp was to be given a wide berth, for with fuel tanks
going dry it would have been the top of folly to invite a long chase
from the Muscovite airmen. And then, too, it was no part of a safe and
sane program to risk an enforced descent in hostile domain.

"Keep her nose southward," commanded Roque, "and we may find the
Austrian lines before we have lost our power. It's a desperate chance,
of course, but there is nothing else to be done."

A precious hour was consumed in fruitless flight, with never a cheering
sign of the friendly forces sought by the anxious aviators.

"It has just dawned upon me that our army has again entrenched in the
mountains, for we could not possibly have come so far in the open
without a single sight that would encourage further search in this
direction."

Roque trained his glasses to the east, where the snow-capped peaks of
the Carpathians were showing in the dim distance.

"It's a good forty miles in that turn," figured Billy, "and whether we
can make it or not with an inch or two of petrol is a close guess."

"Make a try for it, and count on the wind to help."

The mind of the chief was set on this last throw.

One satisfaction to Billy in this change of course was the definite
objective--hit or miss, they were no longer wandering.

Within a mile of the first slope the pilot knew that the jig was up
with the motors. Over his shoulder, he called to the observer:

"This is no Zeppelin with a gas range, and it's the turf for us now."

The motors clanked and ceased to hum. The aëroplane took the downshoot
and skated to a standstill on the slippery soil.

"Stranded but not wrecked."

Roque accepted the inevitable with fairly good grace for him.

"What's the next move?"

Billy was curious to know what the chief had in stock for the emergency.

The boy was not immediately enlightened, for Roque evidently proposed
to reach speech through meditation. The secret agent with his long
coat-tail dusted the powdery snow from a flat stone and calmly took
his ease behind the glowing tip of a long cigar.

"He must have wireless communication with a tobacco shop," thought
Billy, "for he never fails to find one of those black rolls when he
reaches for it."

The young pilot, muffled in a blanket, stuck to his seat in the
biplane. It was his fortune, however, to see the first rift in their
clouded luck.

The color scheme of the mountain side, brown, white and gray, added in
the passing minute some new and stirring effects. On a higher slope
were arrayed a number of men wearing crest helmets, blue jackets and
red trousers.

"Say, boss," drawled Billy, when he caught sight of these gorgeous
figures, "there's a circus band coming down the mountains."

Roque looked up. "Austrian dragoons!" he exclaimed. "We've rung the
bell this time!"

Whether or not the dragoons heard Roque's exultant remarks, they were,
nevertheless, gazing at and pointing to the spot where the stranded
aviators were joyfully anticipating discovery. Willing to aid it,
indeed, upstanding and waving welcome.

The soldiers came in haste to size up the strangely arrived visitors,
and the leader recognized Roque as an oft-seen mixer in official
circles. In calling him by name, however, the name was not "Roque."

The secret agent promptly explained the situation, and received hearty
assurance that he could have enough petrol to carry him back to
Berlin, if he wanted that much.

"We have fifteen air cruisers with us," stated the dragoon spokesman.
"By the way, who is your pilot? You must have plucked him young."

Billy, notwithstanding Henri's patient instruction, was a little short
yet in the Teuton tongue, but he had picked out of the conversation
at this stage enough to put him wise to the fact that he was in the
limelight.

"A bud as to years, I'll admit, my dear lieutenant, but in genius,
skill and daring a full flower; one of the master craftsmen of the
flying profession, and I left a companion piece on the other side of
the mountain."

Threading Roque's eloquent tribute no doubt was the memory of that most
recent rescue performance of the Boy Aviators in the black pass of
Uzsok.

The boy from Bangor felt like the bashful member of a graduating class
when the dragoons committed friendly assault by slapping him between
the shoulders.

"Roten will steal you," laughingly predicted one of them. Billy later
discovered that Roten was the chief aviator at army headquarters.

It was decided by Roque that Billy and himself should rejoin Henri and
Schneider at once, the reunited party returning together to this camp,
and remaining until the development of new plans of the secret agent.

Roten suggested that as it was the intent of the aviation corps to
inaugurate a reconnoitering expedition the following day, it would be
of mutual pleasure and benefit to combine in the trip. Further, he
advised Roque of a much more direct route over the mountains than the
roundabout way uncertainly taken by the secret agent in coming.

"Consent"--this ready acceptance by Roque.

The army air scouts who were to participate in the expedition numbered
eight, and the No. 3 piloted by Billy would measure speed with four of
the swiftest biplanes in this branch of the service.

To the east of the Uzsok pass the Russians had constructed an elaborate
network of cement and earthwork trenches, and to make any headway
against the vigorous Muscovite defense at this point the Austrian
troops would encounter a particularly difficult task.

It was up to the Austrian aviation corps to determine the true strength
of the position, and to weigh the chances of an assault with the
present artillery equipment in support.

So it happened that the little fleet was going in just the right
direction to enable Roque to reunite his own party, at the same time
affording him the opportunity to see for himself what was going on.

Roten had been fully advised of the exact location in the pass of the
forest tract where Schneider and Henri were supposed to be watching for
the return of their companions.

"We will find it without fail," he confidently declared, "and taking
the nearest way there."

A blinding snowstorm, beginning in the night, served to hold the
aviators in shelter for another day. At the first sign of clearing
weather, however, Roten decided to fly, though he explained that many
landmarks would be lost sight of under the drifts, markings recorded
during a previous journey.

"Follow the compass, old man."

This remark, ventured by one of the lieutenants, the chief airman
ignored with a sniff.

"Pass the word to pull out," he snapped.

Five biplanes were off at the signal, and winging their way in perfect
alignment. As far as vision extended billows upon billows of snow
capped the mountaintops and billows and billows of it smothered the
defiles. The observers shaded their eyes as best they could with their
hoods from the trying color effect, heightened by the reflection of the
sun, and many times the pilots made hasty swipes with coat cuffs to dry
wet cheeks.

Roten changed the course more than once during the first hour out,
indicating that he was missing here and there some familiar formation
that would aid the keeping of undeviating progress.

"We ought to get to the jumping-off place pretty soon at fifty miles an
hour."

Billy felt that he had to say something to break the sailing monotony.

If Roque had an opinion he kept it to himself.

There was one thing sure, the flight had carried the aviators beyond
the path of the recent blizzard, for brown and gray were again showing
above the white in the checkered landscape.

That Roten was planning an intermission was apparent by the circling
action of his machine over a plateau of broad expanse, probably an
intermediate station with which he was acquainted.

His initiative set the balance of the flock on the down grade, and the
pilots rejoiced over the immediate prospect of a thaw-out.

The chief aviator wore a satisfied smile on his bewhiskered
countenance. "The Carpathians were never built to down me," he briskly
proclaimed; "we'll go to the mark now like a bullet through cheese as
soon as the steering boys get the cricks out of their backs."

"Come to think of it," volunteered Billy, "it is a tolerably nifty
morning to hold a still curve for a hundred and twenty minutes at a
stretch."

Roten, who understood American, grinned appreciatively at this
recognition of his welfare action in behalf of the pilots.

"Right over there, Mr. Roque," he continued, indicating a summit a
quarter of a mile distant, "is a rise exactly on a line west from where
you started the other day to hunt for petrol--some twenty miles or
thereabouts."

"You ought to have a medal for accuracy, my friend," genially
complimented Roque, "and I apologize for holding the suspicion at least
once to-day that the snow had thrown you out of balance."

"Can't blame you much, sir; I was mizzled a bit by too much white
shroud back there. But here comes Ansel with the oil stove and the
coffee pot, and we will have a brew that will reach all the cold spots
under the vest."

"You must have been born for this kind of business," piped Billy,
viewing the food display on a blanket laid like a tablecloth and the
steaming coffee pot topping the little camp stove.

"I have had some experience in living in and out of an aëroplane,"
modestly admitted Roten, "yet I have seen days when I wished that I
hadn't been born for this profession; hungry days, never-resting days,
ever-perilous days. A sailor may be saved from shipwreck, a soldier has
a fighting chance on the ground, but when an aëroplane goes too far
wrong, just save the pieces, that's all."

"Right you are, sir," earnestly declared Billy; "but get it in the
blood once and there's no quitting."

"By the way, speaking of military aviation, and the cold we have
endured to-day, it is no more a question of climate in that sort of
work. Why, Russia is away up in the hundreds in the number of its
aircraft."

"I expect that is true, Mr. Roque; I know I have met a few from over
there myself," grimly conceded Roten.

"Perhaps some that you will never meet again," suggested the secret
agent.

"Perhaps," said the veteran airman, reputed to have been mixed up in as
many air duels as there were weeks in the year.

Billy, chumming it with Ansel, Roten's pilot, had challenged the new
friend for a footrace, which led the runners to the edge of the plateau
on the north.

Looking across the intervening defile, their attention was attracted by
a movement on the opposite slope, the first sign of life below observed
since they took flight from the Austrian camp early that morning.

"There is something doing over there," panted Billy, not yet recovered
from the exertion of beating his companion a foot or two in their speed
contest.

"I can't tell what it is, though," replied Ansel in broken English.

"It might be a bear," surmised Billy.

"More than one bear, then," claimed the Austrian, "for I just saw two
of the kind between the bushes."

"Your eyes are the better," conceded the boy; "there are two, one with
a big hump on its back. I wish we could get over there."

Ansel shook his head. "You can't cross there on foot. Too deep."

"We can chase back and get the glasses anyhow."

Billy was already on the way for the means of satisfying his curiosity.

When the boy had secured the glasses and was hastening by the group
around the little stove, Roque hailed him.

"What are you up to now?"

"Just going to take a pike at some mountain freak on the other side of
the gully."

"Wait a minute, young man; I'll come and see what you have started."
Roque carried a big bump of curiosity under his cap.

In the meantime, Ansel had told Roten about the slope climbers,
whatever they were, and the aviation leader concluded that any sort of
investigation on this trip required his presence.

The whole company, then, trailed after Billy across the plateau, with a
general view of deciding in force the value of the alleged discovery.

From the lookout point a battery of glasses were soon trained upon the
slope designated by Billy and Ansel.

Roten hit the moving mark first this time.

"I'll be blest," he ejaculated, behind the steady aim of the binocle,
"if it isn't one big man carrying another on his shoulders, and a
shorter fellow bringing up the rear!"




CHAPTER XIX.

RABBIT'S FOOT FOR LUCK.


FOR an hour the Russians in front of the rocky rise, where Schneider
and Henri stood sentinel over the prostrate Austrian officer, had
maintained an ominous silence.

Not a shot had been fired in the mentioned time, and no opportunity had
been afforded the champion stone roller to make another ten-strike in
repulsing attack.

"You can put it in your pipe and smoke it that this brooding over there
means no good to us."

While Henri was not addicted to the pipe, he accepted the figure of
speech, and fully agreed with his companion that the calm had sinister
portent.

"The minute is about ripe," he volunteered, "for us to make ourselves
scarce."

That Schneider was in accord with the proposition had evidence in
the action of removing his boots. To cross a cavity that lowered two
hundred feet or more on the unstable and untried support of a fallen
pine warranted every precaution. There could be no crawling for the
venturesome bricktop. He had human freight to carry on his back.

"Sorry to disturb you, captain," he apologized to the invalid soldier,
"but it has to be done."

Henri, keeping watch at the front, sounded a note of alarm:

"Quick! I see what they're doing--it's a spread, and a three-cornered
charge--they've stolen to the bushes right and left, and the firing
gang in the middle is prepared to pot us if we show head or hand!"

Schneider bent to the task of lifting Schwimmer, the latter groaning at
the movement.

Henri, balanced by Schneider's boots thonged over one shoulder and the
knapsack swinging from the other, made a dash for the slender bridge.
He had determined to first essay the perilous passage, and test the
solidity required to bear the fourfold weight that would follow.

A single misstep, and for the error maker there yawned a pit of death,
a mangling on jagged rocks lashed by the ice-laden rush of a brawling
mountain stream.

But, sure-footed as the native chamois, with never a falter nor a
backward look, the boy made the crossing, backed against the mound of
upturned earth in which the roots of the fallen pine were imbedded,
and fixed apprehensive eyes upon the burdened Schneider bravely and
steadily advancing over the shaking bridge. Once the boy fancied
that, with the earth clods tumbling from the mound behind, the whole
structure was about to give, and he instinctively reached out for what
would have been a vain endeavor to prevent the threatened disaster.

A moment later, with mingled sighs of exertion and relief, the man and
boy clasped hands--on solid ground once more. The wounded officer had
not realized other than that he suffered by the necessary lifting of
his nerve-racked body.

Hardly a second, though, for the silent congratulation. On the level
the defenders had just quitted in such thrilling manner swarmed Russian
pursuers, seeking with fierce activity those who had conducted baffling
resistance for several hours.

"Hear them yell," said Henri in suppressed tone.

"It's a sound better for the distance."

As Schneider made this comment he set shoulder against the
root-threaded mound that anchored the fallen pine. With cracking of
straining sinew the powerful pusher put every ounce of his wonderful
strength into the effort of dislodgment. Thrice he failed, and then,
with a tearing, grinding give, the mass loosened; another heave, and,
as the perspiring giant threw himself backward, just escaping the void,
the great trunk left its moorings and crashed with a tremendous shower
of soil and stone into the abyss.

Schneider in a jiffy, and breathing like a porpoise, dragged on his
boots, again picked up the feebly remonstrating captain, and led Henri
a merry chase around a rocky bend into the bush-grown level tabled
between this and the next mountainous range.

Finally halting, and now beyond hearing of the whoops of the
discomfited Russians, apprised of the escape of their prey by the
crashing fall of the old pine, Schneider indulged in a cheer on his own
account.

"Tough sledding, my boy, but a clean pair of heels to the gentlemen
with the sheepskin overcoats. I don't know what's coming next, yet we
can count on a 'next' coming."

Henri had to put in a sad word, owing to the depletion of the food
store--the knapsack contained less than two days' rations for one man.

The eyes of the two aviators met in meaning glance--meaning that the
remaining food should all be reserved for the ailing soldier, now
sleeping quietly in his blanket roll.

Many a time in the hours of weary tramping did the aviators tighten
their belts, but without a single utterance of complaint or bemoaning
of sad fate. To the gnawings of hunger happily were not added the
torments of thirst. Snow and ice served that desire.

The rations were sparingly fed to the invalid, who, unsuspicious
of the sacrifice of his slowly starving companions, appeared to be
gaining a measure of strength. He expressed sorrow that he must so
burden Schneider in the march, noting that the latter had begun to
occasionally stumble and stagger under the load.

"Don't you bother a bit, captain," as often assured the valiant
aviator, "we will run into a friendly camp before long, and you will be
in fighting trim before the moon changes again."

On the quiet to Henri, however, the big fellow confided that rest hours
must lengthen if he had to fare much farther as a carrier.

He had discovered that in one of his revolvers there were still two
cartridges that had not been exploded, and this find was due to the
intention of throwing away these weapons as useless and cumbersome and
a lucky farewell inspection of the long-possessed arms.

Schneider was a famous shot, with these same pistols had won several
trophies, and, too, in war service had with them seldom failed to stop
an antagonist lusting for his own life.

"Two bullets and three human lives at stake," he mused, weighing the
revolver in his right hand, and aiming it at some imaginary living
target. Several times during the day both Henri and himself had noted
hare tracks in the snow, and Schneider even talked in a hopeful way of
rigging up some sort of trap in the night. While the boy was inclined
to be doubtful as to their possible success as trappers, under the
circumstances, he did not spoil sport, in the mind of his companion, by
adverse argument.

Now there was something tangible in the anticipation that Schneider
might stalk and shoot a rabbit, and so hearten the weakened wayfarers
to renew the battle for existence. They were beginning to lag with
every additional mile traversed.

"Here is a good place to rest," announced Henri, whose sharp eyes had
marked the mouth of a cave among the bushes covering the sides of the
ridge, along which line the footsore travelers had been continuously
plodding for an hour or more.

"We can't stop too quick to suit me," said Schneider, easing his living
burden to the ground.

The cave was shallow, but ample in dimensions for the three invaders,
clean and dry, and containing a quantity of dried moss.

Comfortably placing the invalid, Schneider dropped like a log in his
tracks. He was completely exhausted, and knew no more of discomfort or
the waking world until roused by Henri vigorously tugging at his coat
sleeve. "There's game in sight," excitedly whispered the boy, "bring
your revolver; crawl, and don't make any noise!"

The suddenly awakened sleeper rubbed his eyes, and, comprehending what
was wanted, instantly produced the trusty shooting iron, and as quickly
crawled to the mouth of the cave. Henri pointed a trembling hand to
the little clearing a few yards below them.

Several hares, pure white, were hopping about, scratching and burrowing
in the brown loam, there free of snow.

Schneider had for a second an attack of nerves, similar to that fever
in the amateur Nimrod when first blundering upon the wallow of a buck
deer.

Henri gave the shaking marksman a poke in the ribs.

"Shoot, old scout, or give me the gun!"

By the poke and the hissed demand, Schneider was himself again.

He drew bead on the nearest hare, and with the puff of smoke from
the revolver muzzle the little animal made a frantic leap, ending
in a complete somersault and an inert heap of fur. Another whiplike
crack--and over went a second rabbit, stopped on the first jump to
cover.

"Another cartridge or two and I would have potted the lot," boasted
Schneider, "but even a pair of them is a mighty big draw for us."

Henri missed these remarks, for he was Johnny-on-the-spot to retrieve
the game.

The pistol practice had startled Captain Schwimmer from a doze, and he
was under impression that his friends were fighting off another attack
by the Russians. The captain had begun to take notice of and interest
in what was going on about him.

Raising himself on his elbows, he saw the result of the shooting match
in the pair of plump bunnies swinging across Henri's shoulder when the
boy capered into the cave.

It occurred to the captain to inspect the knapsack upon which his head
had been pillowed. "Is this all the food in the camp?" he questioned,
handling the few scraps in the sack.

Henri nodded in the affirmative, taken unawares by the quick query.

"And I have been eating my fill regularly on this march, have I not?"

"I hope you have not been hungry, captain," evaded Henri, realizing
that the officer was putting two and two together.

"I see it all now," exclaimed the invalid, "you two have starved
yourselves that I might live."

"Shucks, captain, don't put it that way: the rations were yours in the
first place, and, besides, look at the glorious feast we're all going
to have."

Henri's attempt to lightly pass the soldier's revolt against the
self-denial practiced by Schneider and himself resulted only in the
invalid turning face downward on the nearly empty knapsack, his emotion
shown by convulsive movement between the shoulders.

Schneider, wise unto himself, had kept out of the discussion, and had
practically contributed to the settlement of the hunger question by
neatly skinning and cleaning the hare meat.

A hasty fire of dried moss and twigs and Schneider's big knife utilized
as a spit raised a savory odor in the cave, and the picking of one set
of bones that evening helped a lot to revive courage and hope. The
captain, "by the doctor's orders," was compelled to accept his share.

The other hare made the breakfast for the third day out. Schneider
alleged that he had a hunch that this rabbit business had turned the
scale of luck, and to insure the belief he carefully pocketed the left
hind foot of one of the animals.

During the morning the pedestrians, rested and fed, moved in fine style
for the first few miles, Schneider stoutly holding to the efficacy of a
rabbit's foot as a luck producer.

At the foot of the summit finally cutting off the level over which the
party had been so long traveling, it was in order to do some climbing.

"It will give us a chance to look around," cheerfully observed Henri,
"and which chance isn't coming to us down here."

Halfway up the height the boy was again heard from. He insisted that he
had seen a flock of eagles in the western sky.

"Eagles your foot," bantered Schneider; "whoever saw a flock of eagles?"

"Wild geese, then," insisted Henri.

"How many did you see?" quizzed Schneider.

"Five or six, maybe."

"Guess again," laughed the big fellow; "geese would be lonesome if that
was all in a flight."

"Have it any way you please; I suppose you will be claiming next that I
am suffering with liver spots."

Henri was a bit nettled that Schneider did not take seriously his sky
story.

About twenty minutes later, Henri called another halt. "Now, old
scout," he cried triumphantly, "just look up for yourself and say what
you would call 'em."

Schneider, shading his eyes under a hand, scanned the blue expanse
above. "By the great hornspoon," he almost shouted, "I believe they're
aëroplanes!"

Henri was more than willing to be convinced that such was the fact.

"What do you think about it, captain?"

Schwimmer had from the first joined in the sky-gazing contest.

"I think our friend Schneider has solved the problem. I never saw a
real bird with exactly that motion."

The blots on the sky were increasing in size.

"It's a sure thing," hurrahed Henri, "and they're circling for a
landing!"

"Perhaps they're Russians," mildly suggested the captain.

"Not while I'm carrying this rabbit's foot," firmly asserted Schneider.




CHAPTER XX.

WINNING OF THE IRON CROSS.


THE aviators in the party of Roten were all for sailing, post-haste,
to the slope where the mysterious climbers had been sighted, and very
shortly the little fleet was in the air, headed that way.

Flying low, the observers kept a sharp lookout for the near appearance
of the man with the burden and the "shorter fellow."

Roque caught the first glimpse, and called to his pilot to risk a look
for himself. Billy had only a side glance, as the machine rounded the
summit, but that was enough for him.

"It's Henri and Schneider, or their ghosts!" he shouted.

Roque fixed his glasses for the close view.

"As sure as shooting it is, but how in the world did they get here?"

Billy had no ear for this--he was for landing right there, even with
a chance of plowing through the bushes. However, reason ruled, and he
steered for a clearing, into which the biplane promptly plumped.

Hardly waiting until the machine had run its length, the boy was out
and speeding to greet his chum.

It was a regular collision, the manner in which the youngsters came
together.

"Glory be!" This was Billy's high-pitched note.

"Here's to you, Buddy, bully old boy!" Henri cried.

The "bully old boy" then made a dash for Schneider and worked the
latter's brawny arm up and down like a pump handle.

Roque repeated the last-named performance with both the recovered
members of his crew.

In the meantime the Austrians were saluting Captain Schwimmer, well
known to them as a gallant officer in a famous command.

"But for them, gentlemen," gravely stated the captain, nodding toward
Schneider and Henri, "I had been in my last fight. Through danger,
cold and hunger have they brought me, and neither needs a patent of
nobility--nature took care of that."

Roque had only to listen to the happy reunion chatter of the boys to
get the side of the story he wanted to hear.

"It seems," he commented, "that Billy and I were not in the same class
this time with these trouble hunters."

"Do you suppose that there is anything left of our biplane?"

Henri had taken on the air of a sea captain who had lost his ship.

"That is an important question," said Roque, "There is only one fit
mate to that craft in this part of the country."

Fortunately for the preservation of good feeling, Roten did not hear
this latter statement.

It was necessary to detail two corporal aviators to take the wounded
captain back to army headquarters, where he could have the skilled
surgical attention that would hasten his recovery.

As the invalid was lifted into the machine that was to do ambulance
service, he gave a hand each to Henri and Schneider.

"From my heart I thank you both," were his last words in profoundly
earnest farewell.

Henri traveled as a passenger with Billy and Roque in the brief journey
to the forest station in the pass where it was hoped to find intact the
stranded biplane.

Schneider, who had been given a lift by Roten in the trip, was in high
glee when it developed that the No. 3, behind its screen of bushes, had
sustained no damage.

"See that?" The big fellow held aloft the rabbit's foot. "There's no
jinx that can beat it."

Roque was delighted to learn, as the aërial expedition proceeded, that
one of his cherished desires had matured--a large German contingent
had arrived to support the determined effort of the Austrian forces to
relieve the Przemysl fortress.

He had made up his mind that it was well worth the risk to carry back
the new word of hope to the hemmed in garrison, and Roten was informed
of his purpose.

"I regret that you must quit us, Mr. Roque," said the aviation chief,
"but it's the big thing you are going to do, and I certainly wish the
best for your undertaking. Let me advise, however, that not a screw
should be loose when you make that dash. You can't fall in that country
now without bumping a Russian."

"I'll back my boys to make the riffle," confidently asserted Roque.

"They'll need the keen eye every inch of the way," persisted Roten.

"We came out safely, and I guess we can repeat," declared the secret
agent.

"Well, good-bye, sir, and look out for the big guns at Malkovista; the
Russians are there now, and it's only three miles from Przemysl."

"We've come into our own again." Billy and Henri were standing
together, viewing with satisfaction the graceful lines of the No. 3's,
every part adjusted to a nicety. Both boys were well aware that they
were to run a through express.

Schneider had been supplied by a brother aviator with a new outfit of
firearms, and, as usual, was spoiling for an uproar.

"Going, going, gone." His imitation of an auctioneer was excellent, and
with this send-off the biplanes bolted for Przemysl.

The pilots themselves knew the route this time, and they sent the
biplanes over the course at sixty miles an hour.

Three times they were over the fire of long-range guns, but too high
for harm.

Settling in the fortress enclosure, their initial greeting came from
Stanislaws.

"Here's a cure for sore eyes."

This delighted individual capered around the welcome incomers like a
dancing master.

The garrison received with acclaim the news that Roque conveyed.

They had been advised in a general way by wireless from the nearest
Austrian point of the upcoming of the German reinforcements, and this
confirmation in person and in detail added to the enthusiasm created by
the first report.

"Now, boys," said Roque to his pilots, the next evening, "I am seeking
a sight of the gray lines again, and there's another hard flight in
store for you. So get a good night's rest. We start at daybreak."

Facing a bitter, biting wind, the aviators left Przemysl at dawn, and
when they, numbed but undaunted, finally reached the far-away German
lines it was a battle front that they crossed. There the atmosphere
was being warmed by gunpowder flashes, and below was burning petrol,
thawing out the ground that the troops might dig themselves in.

Before the entrenchments, in wide range, combined forces of Austrians
and Germans were locked in a life and death struggle with Russian
contenders for the possession of Warsaw--a bloody repetition in one
spot of the never ending conflict.

Though completing a continuous flight of seven hours, the aviators were
there offered no temptation to alight. Hovering over the banks of the
Bzura they saw a German cavalry detachment all but totally destroyed
by the exploding of a Russian mine, and in turn the big guns of the
Germans cut wide swathes in the Muscovite ranks.

Schneider cheered or groaned as the tide of battle swept forward and
back, when victory favored or defeat menaced his comrades in the fray.
The firebrand, in every quivering fiber, madly craved the chance to
brave the shot and shell on the blackened battlefield.

He saw a German color bearer go down in the press of a hand-to-hand
conflict, and as the mass was dissolved by artillery fire, that
one still figure, among the many scattered in the open, presented
irresistible appeal to the soldier-aviator.

"Land me, boy--have you the red blood to do it? Have you the courage,
lad? You have, I know. Do it, lad--do it now!"

With his incoherent address, the big observer spasmodically clutched
the shoulders of the young pilot.

Carried away by the vehement pleading of the man behind him, Henri set
the planes for a straight fall.

Schneider bounded from the skimming machine, made it the work of a few
seconds to reach the flag, which the dead man had wrapped around his
body, and as quickly returned.

The powerful motors drove the biplane up and across the field, with
the colors trailing over the shoulders of the observer, who, in his
excitement, sang a mighty war song.

This deed of daring, directly in view of the trenches, and under the
very eye of the German commander and staff, raised a tremendous cheer.

Of all this Schneider seemed oblivious. His was a blind patriotism.

Roque wore a look of mild reproach when he encountered Henri behind the
lines that night, but he could not resist the prompting of forgiving
admiration when Schneider stood before him in attitude of apology.

"Had no orders, of course, boss, but something stuck to my crazybone,
and everything went."

"You will have something stuck on the breast of your coat, or I am very
much mistaken," said Roque, extending his hand, which Schneider grasped
with fervor.

That "something" was to be the Iron Cross, the famous decoration for
valorous service, and the most coveted distinction in the German
empire, a badge of courage woven into its military history.

"Were this boy a soldier of and for the Fatherland," solemnly continued
Roque, "the royal gift might well be bestowed upon him."

Schneider threw an arm around the shoulders of the young aviator. "Of
nothing else is he lacking to claim the honor," feelingly maintained
the big fellow, and his eyes were moist as he spoke.

Henri shook his head. Then with a roguish glance at his chum, he said:

"The only medal I am hankering after is the one Billy and I are
expecting for making the first aëroplane flight across the Atlantic."

"Have the 'made in Germany' mark on your machine and I believe you can
establish the record," laughed Roque.

"Not on your life," exclaimed Billy. "We are going to build the
crossing craft ourselves."

The No. 3's were lying idle behind the lines. Roque had ceased
overground work for the time being, and like a mole was engaged in some
undermining scheme, of which the boys had no inkling.

Resorting to his remarkable aptitude as a lightning change artist,
and also applying the magic touch to Schneider, the pair of them were
scarcely recognizable to even the lads with whom they had been so long
and so closely associated.

The secret agent and his trusty lieutenant were masquerading as natives
of Russian Poland, and it may be told that their desperate mission was
to enter Warsaw, where the slightest indiscretion or betrayal would put
them in graves alongside of that daring spy of Roque's who failed to
conceal his identity.

It was the midnight hour when Billy was awakened by a man enveloped
from neck to foot in a grayish-brown overcoat, from under the head cape
of which came the voice of Roque:

"Take this" (slipping a fold of coarse paper into the hand of the
drowsy lad), "and if you do not hear from me after three days, read
what is written, and follow the instructions to the letter. Not a look
at the message, remember, for three days; to be exact, the morning of
the fourth day. You hear me?" Billy sleepily nodded his head.

Out on the turbid tide of the yellow river beyond the German trenches
two shrouded figures silently launched a flatboat and drifted away in
the darkness.

"What's doing?" This was Henri's morning question, preceding a swallow
of coffee.

"If I knew what was in here I could probably tell you a whole lot that
I don't know at present."

Billy displayed the closely folded packet containing Roque's
instructions.

When Henri was advised of the conditions imposed he accepted the trust
as a matter of course.

It had never been a habit of the boys to break faith.




CHAPTER XXI.

HELD IN WARSAW.


THE din of battle had long since ceased to be an inspiration of terror
with the Boy Aviators. They were case-hardened by continual contact
with the war game, and too careless, perhaps, of flying lead.

Reclining in the trenches, they indulged in all sorts of surmises as to
the whereabouts of Roque and Schneider, wagered back and forth, one way
and the other, on the proposition of whether the chief would appear in
person within the allotted time or put it up to them to interpret the
message in Billy's pocket.

With the passing of two days, the hours in the next one seemed to move
on leaden wings.

"I don't even know in what direction to look for his coming,"
complained Henri. "If he is coming," he corrected himself.

"No use getting in a stew about it," advised Billy, concealing the fact
that he himself was nearing the boiling point as the last few hours of
waiting wore away.

The morning of the fourth day, and no sign or sight of the absentees.

Billy and Henri sat in council, and the former opened the paper that
had haunted his dreams during the previous restless night.

    "If alive, we are in Warsaw."

"I guessed that once." Billy lifted his eyes from the paper.

"Go on," impatiently urged Henri.

    "Of either fact you may learn by following instructions.
    You are to bring both biplanes, early morning, and circle
    over the city. In the south section you will note tall
    column with figure on top in center of square. Back of same
    is elevation on which rise two towers. Watch these. If
    one flag shows, hold over high road running west; if two
    flags, sail north and land at lodge house where canary sang
    for us. There wait. If highroad route (one flag), see red
    scarf signal for drop. When you read and commit these lines
    destroy."

"What a system that old fox controls," observed the reader. "Killing
one of his men didn't close the show in Warsaw. Do you get all this,
pard?"

"I think I do," asserted Henri, "but let me go over it again to be
sure."

Both boys having Roque's communication pat in their minds, Billy tossed
it into the flames of the nearest campfire.

The aviation lieutenant serving with the division gave them free reign
and all possible assistance in preparing for their flight. He asked no
questions.

Crossing the river, the young aviators ascended to great altitude,
hardly visible to any casual ground view, and taking lower levels
gradually over the city. Each with an eye on the compass, the pilots
mentally rehearsed their instructions.

Operating in unison, though a hundred yards or more apart, they checked
speed when sighting the burnished tower tops showing above all other
structures on the south line, first identified by the tall column and
its surmounting statue in the square.

The aërial maneuvering continued for a seeming quarter of an hour, and
while the sun rays splintered on the glistening turrets over which they
were keeping vigil, no other manifestation appeared.

Through this long exposure to the danger of attracting unwelcome
attention, the boys were momentarily expecting some aëroplane
demonstration from the Russian military camps showing to the east.

On the highroad, finally, the aviators saw two horsemen galloping their
mounts towards the hill, and then lost to view between the twin bases
of the towers.

A flag swung out from one of the tiny windows under the gilded domes.

One flag:

The signal to hold over the road, which stretched whitely for a mile or
more and merged into the fertile fields without the city.

The red scarf next. Would it call the suspended biplanes in swift swoop
to the earth?

Skilled hands gripped the levers in readiness to instantly respond to
the signal.

A cart with two muffled figures in it rumbled leisurely down the road.
There was no urging of the sorry steed straining at its belled collar.

The biplanes perceptibly lowered, though it was merely guess work on
the part of the aviators. The movement of the cart might have been just
one of ordinary traffic, the occupants just plain, everyday peasants.

Suddenly the hovering airmen got a signal, but not the expected flash
of scarlet. One of the carters, a big fellow, rose from his seat and
frantically waved his arms, and the boys were then so near that they
could plainly see that he varied the queer performance by pointing
skyward with the long whip he was holding.

So intent had been the aviators in trailing the cart that they had
neglected for a time to look elsewhere about them.

The gestures of apparent warning that they were witnessing returned
their wits to normal, and what they had from the first low flight
feared was about to be realized. Barely a half mile away, and buzzing
toward them, were three aëroplanes, which, unnoticed by the otherwise
engaged lads, had risen from the Russian camp.

Billy and Henri, now wholly confident that the antics that had awakened
them to the impending peril were those of no other than Schneider, gave
that good friend a parting salute of cap waving and turned about at
full speed to lead a stern chase over and beyond the city--far beyond,
it proved.

The pursuing biplanes, of the largest type, carried a crew of three men
each, and that they had tremendous motor power was evidenced by their
catapult coming.

But, light-weighted, the No. 3's were not to be easily overhauled. It
must have been a contrary spirit that induced Billy and Henri to do
other than head across the river to the German camp.

They were in their element, however, and it was the kind of exploiting
that most appealed to them. Keeping out of range of the guns of their
armed pursuers was the first care, and no other care had the lads how
long the chase continued.

They would even hold, as a bait to keep the fun going. That grave
consequences might follow capture was not at all an issue. The boys had
no thought of aught else than that they were jockeying in an aëroplane
race.

How far afield they had driven they did not realize until with waning
day they had outdistanced their pursuers.

They were compelled to land in strange territory, for they feared
to take the chance of exhausting the supply of petrol carried by
the aëroplanes, and, besides, the continued strain on the aviators
themselves was beginning to tell.

"Oh, for a 'lodge in some vast wilderness,'" spouted Billy in actor
style. He had a very pleasant memory of that lodgekeeper's kitchen, in
which they, cold and hungry, had been warmed and fed. "I'd like mighty
well," he added, "to hear that canary twitter right now."

"Barring all that," remarked Henri, "we might be in a worse fix,
considering that we have something to eat with us and a good pair of
blankets for a bed."

"I am not particularly impressed with these surroundings, though,"
argued Billy, "a swamp on one side, a bunch of stunted willows on the
other, and a regular no man's land front and back."

"Oh, quit your kicking, Buddy, and let's make the best of it."

Henri started for the willows, in the hope of finding enough dry
material to make a fire.

He succeeded in coaxing a small blaze out of a little pile of twigs.

Dead tired, the boys rolled into their blankets and slept like logs.
But they had a rude awakening, particularly in the case of Billy.

As he lay snoring, a flash more vivid than lightning dragged him out
of dreamland, and his hands flew to his eyes to protect them from
the blinding glare. A searchlight was playing full on his face. He
heard the clatter of horses' hoofs, and before he could see what was
happening, a hand was on his shoulder and a revolver was pressed
against his breast.

Henri, startled into sitting posture, looked dazedly upon the
proceedings.

A Russian cavalryman, dismounted, was behind the revolver, and the
searchlight was directed from a wagon.

A stalwart figure in gold and brown, an officer in the service of the
Czar, moved briskly into the circle of light to inspect the prisoners.

Stroking his tawny mustache, he concluded brief comment with a short
laugh. Translated, what he said was:

"You have caught a pair of lambs, Peter."

The soldier addressed as Peter hastily restored the revolver to his
belt.

Another soldier just then discovered the biplanes, and the officer
deemed this find of great importance. He tried the French language on
the boys in starting a series of blunt questions.

"Who and what are you?" he demanded.

"Aviators by profession, foreigners by birth, and prisoners because we
couldn't help ourselves."

The officer smiled at Henri's smart answer.

"I suppose you came to this spot in those machines?"

"Yes, sir," replied Henri, less snappy in tone.

"We will hear more from you when we get to Warsaw," advised the Russian.

"Shades of Tom Walker," thought Henri, "'out of the frying pan into the
fire.'"

"Peter and I will go along with you by the air route," proposed the
officer; "I like the looks of those machines. We need them. Now, Peter,
you must not let your pilot run away with you."

Peter grinned and tapped the butt of his revolver.

Captain Neva, for such was the Russian officer's title and name, was
a rather advanced amateur in knowledge of aircraft, and he shrewdly
estimated the value of the prizes that had come to his hand on this
night's march. The subaltern, Peter, had also some flying experience,
though he preferred a good horse under him rather than a board, and
he, too, noted the fine points of the No. 3's.

"A pretty present for the general, my captain," he rejoiced, "and all
ready for delivery."

The boys were given a substantial breakfast, and Henri learned that
they were about 150 miles north of Warsaw. As this was figured on
straight line measurement, the aviators realized that in the excitement
of yesterday's racing they must have left the direct course many times,
for considering the time they were in the air and the speed maintained,
150 miles was not a great distance.

From one of the many wagons, loaded with ammunition and military
supplies of all sorts, was produced a fresh supply of petrol for the
biplanes.

"You see, we have quite a number of these flying machines up in
Warsaw," explained Captain Neva to Henri, "and we are carrying plenty
of this stuff to feed them."

In a few minutes the biplanes were off for Warsaw, Henri and the
captain in one machine, Billy and Peter in the other.

Three hours later the boys walked behind the captain into army
headquarters, and soon into the presence of a man of most distinguished
bearing, in full field uniform of a Russian general. Though gold lace
sparkled on his shoulders and his cuffs, the striking note of his
attire was the orange and black ribbon of the Cross of St. George that
appeared along the buttoned edge of his field coat.

Captain Neva presented the compliments of his colonel, told of the
near approach of the supply wagons and convoying troops, and mentioned
the handsome addition to the aërial fleet so luckily and peculiarly
acquired. The captain's brief relation of the latter incident, a little
break in the pall of war, seemed to interest the general, for he
glanced at the lads, standing at respectful attention nearby.

"What is your name?" he asked, speaking in French, and looking directly
at Henri.

The boy politely bowed and named himself.

"I would conclude from the sound that I have spoken in a tongue within
your complete understanding. And the other?"

Henri registered Billy, name and nation.

The boy from Bangor flushed with gratification when the general, in
excellent American, called him forward.

"You're a long way from home, young man."

Billy admitted the fact, and added, "I have been wishing many times of
late, sir, that the distance could be reduced three-fourths and I had
already traveled the other fourth."

With the incoming of the staff members, reporting from the front, the
general consigned the boys for the present to the custody of Captain
Neva.

"They've wasted no time," observed Billy, pointing to the familiar
lines of the No. 3's, glistening with new color.

That a couple of Polish carters should happen to be gaping at the
aviation show was not an unusual occurrence or usually worthy of notice.

But there are carters and carters, and some seeming carters are not
carters at all!




CHAPTER XXII.

AN HOUR TOO SOON.


WITH incoming of the troops convoying the supply train, Captain Neva
rejoined his company, and Billy and Henri were promptly adopted by
the aviation corps, most of whom spoke both French and English, and
all very much inclined to express their admiration of the aëroplane
knowledge displayed by the youngsters.

The boys were right on the job, so to speak, when it came to
reassembling the parts of new aircraft received by wagon shipment, and
so grew in the confidence of the aviation lieutenants that they were
quite often permitted to make flying tests of the various machines with
only themselves in charge.

If the young airmen enjoyed this concession without watching on the
part of the lieutenants, there was no such inattention on the part of
a couple of frequenters of a city tavern not far removed from the
aviation camp.

Work was evidently slack with this pair of citizens, for hardly a day
passed that they did not spend several hours at a tavern table located
near a bow-window, which afforded an excellent view of the parade
ground and aviation quarters.

One of these constant spectators was remarkable for his size and the
vivid hue of his hair, the other for the reason that he paid absolutely
no heed to the other patrons of the place, though all appeared to be of
his kind, both in manner and attire.

On a particular afternoon, the strangely silent one was deeply engaged
with a stump of a pencil in the labor, no doubt, of casting up his
accounts on a piece of dirty brown paper, in which had been wrapped his
lunch of black bread and sausage.

The puckered lines over his nose indicated thought labor, but the
furtively keen glance he occasionally gave to outside movement
contradicted the impression that he was of slow order of mind.

The chief actors in the mentioned "outside movement" at the time were
two trimly set up lads in new suits of service green, one pulling and
the other pushing an armored biplane into its hangar.

"This machine," said the puller, "ran like an ice-wagon to-day but
maybe use will smooth her out."

"It's all in the motors," confidently asserted the pusher, "and I'll
have the kinks out of them in a day or two."

The man at the table across the way had completed his task, shoved the
paper and pencil into his pocket, and was placidly puffing a huge cigar.

His red-topped companion stamped into the room, returning from some
excursion in the city, but the smoker did not pass a word of greeting,
though the other idlers filled in with noisy welcome.

It was not until the room had been vacated by all but themselves that
the curiously assorted pair put their heads together.

"Ricker showed you where the ammunition was stored?"

The red-topped nodded.

"You arranged for the plans with Westrich?"

Again the nod of assent, but this time with softly spoken supplement:

"All good, but there is no chance of us getting to the river now. It's
lined with a wall of steel, and even a rat could not pass, day or
night, without a triple stamp of authority on its back. And let me tell
you, if we light the match for that explosion without an outlet, all
the information we will carry will be to the next world."

"If we cannot get through the wall of steel you mention there might be
a way of going over it."

The speaker gave a meaning glance out of the window at the aviation
camp. A biplane was just rising for test flight, and it was manned by
two experts easily identified by the conspiring couple in the tavern.

"Oh, ho, I see," mused the brick-top, "you expect to use those boys in
the matter of pulling us out."

"Why not? Have they ever failed us in extremity? Is the peril greater
than when they dived into the canyon that our lease on life might be
lengthened; did they fail to respond to my summons to do this very work
of rescue, delayed through no fault on their part?"

This subject had served to draw the clam out of his shell, and he found
relief in relaxing temporarily his studied pose of stolid indifference.

"How are we going to get at them?" asked the willing listener to the
rapid-fire praise of the young heroes.

The crafty secret agent (it was Roque, of course) had not been
wool-gathering during the silent hour of his sitting at the table.

He had devised several ways of apprising the boys that he needed their
services and acquainting them with a working plan that would enable
them all to sail out of Warsaw in safety.

Something was going to happen when he willed it that would make the
outward passage a memorable one, and success or complete failure of the
project was in the close balance of a few more hours.

In real truth, however, Roque did not so greatly weigh his personal
welfare as against the service he could render by doing damage to the
foe from without as well as from within.

Ready for his call were papers of supreme import, and to lose which at
the hands of a searching party would be a calamity the secret agent
dreaded even to anticipate.

By the air route he had determined to leave, if by any hook or crook
Schneider and himself could get hold of an aëroplane.

Billy and Henri had been aloft for several hours, enjoying a bird's-eye
view of the really magnificent city, for the possession of which
carnage held sway for hundreds of miles.

"Some town this," Billy remarked as he stepped from the machine,
completing the sightseeing tour; "after the war I'd like to start a
branch factory here."

"Oh, go 'way," laughed Henri, "it would take a derrick to haul you out
of Boston or Bangor, once you set foot again in those burgs."

"You forget, old top," suggested Billy, "that we have already on tap a
comeback aëroplane trip across the Atlantic. I'm no quitter."

From a coal-laden wagon the contents was being shot into a chute
running into the cellar of one of the big houses taken over for
officers' occupancy.

One of the grimy heavers, at sight of the boys, came forward to meet
them, wiping his hands on the leather apron he wore, removed his fur
cap, and took therefrom a scrap of smutty brown paper and tendered it
to Billy.

"Guess he wants you to sign a receipt," said Henri, looking over his
chum's shoulder.

Billy's glance at the paper set him staring at the man who presented it.

The latter never raised his eyes--he was using them sidewise upon a
group of soldiers standing in front of the mess hall.

The boys saw in the scrawl these words: "Orders for No. 3's, Two
Towers, St. Michael road, eight sharp, Thursday evening."

Without a word, Billy returned the paper to the heaver. The officer of
the day was approaching. He signed the delivery receipt, but the paper
had queerly changed color in the handling.

As the lads slowly walked toward aviation headquarters their minds were
all in a whirl. Prisoners they were and prisoners they had been, yet in
both instances it had been but the semblance of captivity. While they
were held, the rein had been a loose one.

Just back of them the ties of long association, immediately in front
of them a trust imposed, a generous parole, when they had gone to the
limit in giving the best of themselves, in the one capacity they could
serve, to the former rule.

Thursday evening at eight, and this was Tuesday evening at six. Long
enough, indeed, for the boys to torment themselves with the reflection
that if they did not appear at the appointed hour Roque and Schneider
would curse their perfidy, and if they did betray the confidence of the
aviation chief in this camp he would pay the penalty.

"It will be no trick at all to take the biplanes for an evening spin;
we have done it before without question."

"That's the trouble, Henri", lamented Billy, "it's too easy. If we
had to steal the machines, risk our lives before the guns of the
sentries, and all that sort of thing, it wouldn't seem such a trial of
conscience. But they take us on trust, and without question."

"Yet, here's Roque and Schneider in the lurch, and looking to us for
aid. With them we have met about all that is coming to a fellow in this
war zone, except death, and pretty near that; we have eaten and slept
and starved together."

"There you are again, Henri, and it's 'twixt the devil and the deep
blue sea!' any way you put it."

Thursday morning, and as clear as a bell. The Boy Aviators looked
red-eyed on the smile of nature. Their cots had squeaked protest all
through the night against the tossing of the uneasy nappers.

At noon they had about made up their minds to keep the appointment at
Two Towers, and seeking to strengthen this resolution they avoided in
every way they could meetings with the aviation chief.

Along about three in the afternoon the wavering youngsters had arranged
a compromise, this to be positive. They would deliver the No. 3's to
their former owner for choice, and so enable their old friends to get
safely away. As for themselves, they proposed to return to camp and
"take their medicine"--their dose and the portion that the aviation
chief would otherwise be likely to get.

But fate shuffled it another way.

The workday was in the closing minutes. The remaining city thousands
who were not in military service were swelling the stream of homegoers
in the busy streets.

The driver of a coal wagon, which had drawn up before an imposing
structure devoted to the storage of army supplies, and supposed to
contain an immense supply of ammunition, suddenly conceived the notion
that he was doing overtime duty. At least such was his manner when one
of the Big Ben clocks overhead ding-donged the hour of six. Perhaps,
too, the movement of gathering up reins and whip had its measure of
prompting in the appearance of the driver's mate from some underground
space in the big building.

At any rate, the old nags dragging the heavy vehicle were given the
full benefit, and without warning, of a long and knotted whip-lash,
and covered several city blocks at a lively gait before they realized
that they were traveling out of their class.

The heaver who had emerged from the building in response to the clock
summons showed tremor of the hands when he lifted them to draw the cape
of his greatcoat closer about his throat.

"It's set for eight," he hoarsely whispered; "I turned the key when I
heard the strokes outside."

Strangely enough, the wagon kept a course directly to a residence
section at once fashionable and quiet, and hardly the possible location
of a coal yard or the home, either, of a humble employee thereof.

One of the men in the wagon, the fellow with the hoarse whisper, left
the vehicle in a square marked by a tall column with a statue on
top, while the driver continued the urging of his horses up the ever
ascending street.

Gaining the level above, the horses were given their own heads, which
meant a snail's pace. Close at hand were two towers of considerable
height.

While the horses plodded on the highroad stretching to the west,
pressure on their bits was lacking. The wagon was empty.

Two figures appeared on the terrace back of the twin towers, these
terraces rising in tiers from the bank of the fast-flowing river below.

"You left Ricker in the square?" This question put by the man who
evidently had just returned from a mission that did not include a ride
in a coal wagon.

"He left me, rather," replied the late driver, with a touch of grim
humor.

The first speaker held a watch in his hand, consulting it frequently,
holding it closer and closer to his eyes as the light faded before the
advance of night's shadows.

"Seven o'clock," he announced. "Another hour."

This was the last notation of time by the watch holder.

There was an explosion that, notwithstanding the distance, seemed to
shake the everlasting hills to their very foundations.

The men on the terrace stared aghast, each at the other.

"The die is cast," cried the one with the commanding voice, "and an
hour too soon!"




CHAPTER XXIII.

A LEAP FOR LIBERTY.


THE Boy Aviators had just left the mess hall, and were proceeding to
the hangars where the No. 3's were housed, fully intending to carry
out their compromise plan of giving Roque and Schneider the means to
escape, and return themselves as hostages for the honor of the aviation
chief.

Shortly before seven o'clock on this eventful evening, Billy and Henri
had the biplanes in order for the arranged visit to St. Michael road,
and the delivery of one or both of the machines to their former owner,
supposedly in waiting in the shadow of the two towers.

"It is really a relief that the time is drawing nigh for us to get off
the rack. I believe we are doing the square thing, but sure we have had
few easy moments during these last forty-eight hours."

Billy heaved a sigh when reviewing this disturbing experience.

Henri turned just then to salute the aviation chief. The boy's greeting
had none of the cheery note usually there. He did not know how it would
be several hours hence.

"Looks like a chance for you boys on the next dispatch trip to
Petrograd," advised the chief; "we can illy spare more than two at a
time of our regular air scouts, and here's a deal by which we have two
extra machines and a pair of pilots thrown in."

With their minds clear and no cloud like the one looming ahead, the
prospect of biplaning to the wonder city of Russia would have set the
boys on the top floor of enthusiasm.

As it was, they could only say that they would welcome the work if it
should be assigned to them.

The aviation chief had hardly taken a dozen steps in his continuing
round of inspection when there was a shakeup that might have come by a
combination of volcano and earthquake.

"Geeminy!" gasped Billy, clapping his hands to his ears, "somebody must
have fired a ton of powder!"

A roll of drums preceded the hasty assembling of several regiments in
this division, and a squadron of cavalry jingled madly down the street.

"That was a whopper, all right," exclaimed Henri, righting himself
after his first little stagger from the shock, "but big noises ought
not to queer us, pard. Get in and get away."

Following his chum's example, Billy was close behind the former in
upward flight.

They could see that the streets below held literally surging masses of
humanity, all trending in the same direction.

The aviators speedily gained an idea of what had happened. That which
only the other day they had observed as a solid front of granite and
iron on a building covering practically a whole city square had fallen
in ruins, completely blockading the broad avenue it had faced.

About the square a cordon had been drawn, and it could be seen, even
through the dusk, that troops were spreading fan-shape from this point
throughout the entire northern section, while the police darted right
and left and everywhere.

The select neighborhood of St. Michael road had not been omitted from
the general round-up, the boys found, when they approached the site of
the two towers.

It seemed that the abandoned team and wagon had been found somewhere
along the highroad, and as suspicion was now acute, the discovery set
the fine-comb going along every terrace and police poking in every
likely hiding-place.

There had been instant acceptance of the theory that the storehouse and
magazine had been deliberately blown up by the cunning contrivance of a
spy or spies within the city.

Every stranger must give an account of himself, and even some
individuals here and there who were not newcomers.

Billy and Henri could see no opening where two full length military
biplanes could alight without notice, and not a morsel of encouragement
to try for negotiation on the quiet with the disguised secret agent who
had summoned them.

But the aviators hung about, not knowing what else to do for the
present, thinking that Roque would make a showing of some sort, as he
usually did in tight places.

Flying lower and lower, the two biplanes were sweeping within earshot
of the terraced heights along the river front, and though now of dim
vision, searching parties could be seen flashing lights up and down the
ground tiers.

There was a hullabaloo breaking out on the lowest terrace, immediately
overhanging the river--a shot--another and another--like a bunch of
firecrackers, so fast did they follow!

A stentorian note of defiance, a rush, two shapes springing out into
space, a great splash in the icy waters below!

If the morning revealed a single trace of the daring fugitives dead
or alive, no word of it reached the aviation camp, to which the young
airmen had returned, conscious that of this mission they were acquitted.

"Do you know, I can't help believing that they got across?"

Henri had a thought, perhaps, of the rabbit's foot that Schneider
carried.

The boys had many under-the-breath discussions as to the possible
connection of Roque with the explosion that had destroyed the war
depot. They had no reckoning that in the little shop of a silversmith,
not far removed from the very column and statue that had twice served
them as a guide-post, the whole story might have been told by a wily
confederate posing as a peaceful artisan. This same man could also have
confessed to the first error of his expert career in the handling of a
time-clock.

With plots and counterplots, however, the young aviators had no time or
inclination to meddle. They would rather work in the open.

"I wonder if that lieutenant meant what he said about giving us a peek
at Petrograd?"

Billy put the question to his chum as they contemplated with
satisfaction a particularly neat job of aëroplane repair they had just
completed.

"Don't see why he should say it if he did not mean it," replied Henri.
"Next time he comes this way there would be no harm in reminding him of
what he said."

It so happened that the aviation chief at the very moment was headed
for the hangars. He was accompanied by two officers of apparent high
rank, who gave the various types of aircraft close and critical
inspection.

When the No. 3's came to their notice, one of the officers, a grizzled
veteran, with a livid scar showing from temple to chin, halted with a
pointed word of commendation.

"There's speed, balance and strength for you. Where were they built?"

The aviation chief explained.

"Ah, I see," said the officer, "the paint only is ours. Well, I think
we need look no further. Get them ready for immediate use. Where are
the pilots for this assignment?"

A call was passed for Billy and Henri.

When they faced the official visitors, both of the latter turned a
stare full of question marks at the aviation chief.

"Are these the sons of our pilots to be?"

The senior colonel meant to be a bit sarcastic.

"No; but if the fathers really were as remarkably skilled in the high
art of aëroplaning as 'the sons' you see here, I would request the
general to let me go after them without delay."

The airman was very much in earnest in his firm but respectful effort
to correct the impression of his superiors in command that he had been
guilty of some error of judgment.

Henri unconsciously contributed another entering wedge when he gave
his name to the younger of the colonels, who had taken a hand in
the examination of the youthful candidates proposed by the aviation
lieutenant for special aëroplane service.

"Trouville!" exclaimed the officer; "are you of the house founded by
the first François and the motto 'Sans Peur'?" (Without Fear.)

"That's in my family record, sir," admitted Henri, who could not
imagine what on earth his ancestry had to do with his ability to run an
aëroplane.

"Then you will find an open door in Petrograd," proclaimed the colonel,
"that of my father, who in his day of travel was often a guest at the
Château Trouville, when your grandfather lived and they were kindred
spirits in the world of art."

"Château Trouville and its art treasures are no more," sadly recalled
Henri.

"My father will mourn with you there," assured the colonel.

Another assurance came from the aviation chief when the officers
had returned to army headquarters to assist in the preparation of
dispatches that were to go forward by aëroplane within the hour. Said
the lieutenant:

"It is settled, my flying friends, that you are to go on this journey,
which is imperative, owing to the investment of railroad connections.
The observers behind you will point out the route, and easy to
follow, as the river is ever in sight. As to the rest, you need no
instructions."

"We are ready to start at the drop of a hat, sir," declared Billy. The
boys had tuned the No. 3's to the point of perfection.

The observers and dispatch bearers, Marovitch and Salisky, honor men in
the service, soon appeared, hooded and enveloped in furs.

The first named handed Henri a card. "From Colonel Malinkoff," he said.
The boy saw that it contained the words "He is a Trouville," signed
"Alexander," and directing to a certain street and number in Petrograd.
Henri carefully pocketed the valuable reference.

In the early afternoon the young aviators had their first view of the
capital city of the Russians, at the mouth of the Neva, and they made
landing upon a massive granite quay on the south bank of the big river.

As the boys walked with the special messengers to Admiralty Place,
they marveled at the colossal proportions of the public buildings, and
looking up and down one magnificent avenue, five or six miles in length
and 130 feet wide, Billy squeezed the elbow of his comrade, with the
awed comment: "There's all outdoors in that street."

"That's the Nevskoi Prospekt," advised Marovitch.

"The very name on the colonel's card," cried Henri, "Malinkoff palace,
too."

"Know it very well," put in Salisky, "a twenty-minute ride, and you are
there."

When the dispatches were delivered the boys were not present, but
there was no lack of interest for them outside. Standing near the
copper-inlaid doors through which the messengers had passed were a
number of Cossacks, dressed in scarlet, gold-braided caftans, white
waistcoats and blue trousers.

"That's a fancy looking bunch," whispered Billy; "I guess they are
something extra. And--say, Buddy, if my eyes don't deceive me that
fellow in the middle, the one with the bushiest beard, is no other
than the boss of the crowd who shoved us in the cellar over in Galicia!"

"Cracky, what a pair of eyes you've got, old scout, and sure it's the
very same, though he doesn't look as rusty as he did then."

Henri seemed to be fascinated by the discovery, and watched like a hawk
every movement of the old enemy in the new garb.

About that time the Cossack happened to cast a glance in the direction
of the spot where the boys were stationed, and two pairs of eyes met
in a single flash. In the fierce orbs, and under the beetling eyebrows
of the knight of the mountains and deserts, the flash plainly conveyed
a puzzled expression. Henri lowered his look. This risk of recognition
was more than he intended his bid to bring.

Turning away, the boy sought to show his indifference of the now
strained situation. He managed to get an aside to Billy, in effect:

"I'm afraid I've put my foot in it now."

With the reappearance of Marovitch and Salisky, Henri, in subdued tone,
requested information regarding their brilliantly attired neighbors.

"Why," responded Marovitch, "they are of the personal escort of the
Czar."

"Good-night," thought Henri, "it's a fix we are into, and less than two
hours in the town."

"How far did you say it was to the Malinkoff palace?" he suddenly
asked.

"Oh, about two miles up the Prospekt," said Salisky.

"Hail one of those carryalls, please," requested the aviator, pointing
to the nearest stand of vehicles for hire.

The Cossack had followed them, and was slowly descending the marble
steps just quitted by the boys and their companions. He was evidently
still debating with himself.

The driver of the chartered vehicle cracked his whip and carried his
passengers up the street as fast as his heavy horses could gallop.

With a speed ordinance he had no acquaintance.




CHAPTER XXIV.

AGAIN THEY WON OUT.


DRAWING up with a flourish in front of a most pretentious example of
old-time architecture, the fur shrouded jehu reached for his fare,
which matter was adjusted by Salisky, who had orders from his colonel
to see the boys through from start to finish.

At the onyx-studded entrance of the palace the party was halted by
a gorgeous flunky, who immediately unbent at a word from the useful
Salisky.

"The colonel must belong up in the pictures here," suggested Billy,
duly impressed by the surroundings.

"He is a great noble as well as a great soldier," reverently remarked
Marovitch.

"Well," chuckled Billy, "I'm going to keep on my shoes, even though I
walk on velvet."

Salisky gave the lad a side glance of disapproval of this levity, of
which the young aviator took not the slightest notice.

But Billy warmed to the gracious presence revealed by cordial greeting
in the spacious drawing-room.

The card from Colonel Malinkoff had preceded the visitors.

With Marovitch and Salisky in the background, the boys were ushered
forward to meet a real, live duke, but, withal, a kindly gentleman
without a mark or an affectation of exalted rank.

"Which, may I ask, is the Trouville, the grandson of my old friend?"

Henri bowed acceptance of the honor. With fine and delicate courtesy
Billy was made to feel that he was not counted a crowd by being the
third participant in a cozy chat.

The duke delighted in his memories of the close alliance he had
maintained with the house of Trouville, and received with extreme
regret the information that the old château had been razed by the
engines of war.

"I well remember the underground passages, the walled ways, the secret
panels, and the like of the ancient place."

Henri nudged his chum, and then briefly narrated how the fortune of
the Trouvilles had been saved through the use of these same concealed
avenues and by the plan of the same two boys now sitting in this
drawing-room.

The old noble listened intently to the story, told without
embellishment or boast, and at the point where Henri referred to the
delivery of the treasure to his mother the duke clapped his hands in
applause.

"Salisky," he called to the special messenger, "I desire to keep
these young gentlemen as long as possible. Is there an emergency that
commands their return?"

"Your grace," stated Salisky, "it grieves me to say that it is most
important that they serve as pilots in our journey back to the front.
Even now dispatches are being prepared, and we must be on the wing at
sunrise to-morrow."

"Ah, the same duty that holds my son in its grip, the call of country,
and which by my infirmity of years I may not answer. Not your country,
my boy, but your trust, nevertheless. But this is not your last visit
by many, I sincerely hope. A Trouville, a Trouville," he muttered,
"without fear."

"Oh, another thought, you have not broken bread with me." The duke
struck a bell on the table at his side.

The gorgeous flunky led the way to the smaller of the dining-rooms, the
other would have held a regiment, and if the food was plain, on the war
basis of all alike, there was a bountiful service of it.

From the dining-room windows the Prospekt could be seen, and Henri
saw something besides the Prospekt--several horsemen in parti-colored
uniforms pacing their mounts slowly up and down in front of the palace.

He telegraphed with a wink to his chum, who was seated with his back
to the windows. Billy took the tip, and managed to get an overshoulder
look on his own account.

The interest of the boys as to affairs inside instantly began to flag.
True, they were under powerful protection for the time being, but there
was a later time coming.

The Cossack must have struck the lost chord in his memory. There had
since the encounter in the Galician farmhouse been a life added to the
claim of the red rider--the duelist that Schneider had forced over the
cliff.

Henri had a game to play--playing for time. Appeal to their host, for
various reasons, did not impress the boy as a desirable proceeding.

"There is no need of our going back to Admiralty Place right away, is
there, Salisky? We don't sail until morning and we haven't even seen
the paintings here."

"The paintings"--here was a master stroke. The duke was touched at a
point nearest his heart.

"You must have at least a passing look," he insisted.

Salisky uneasily shook his head. "We have orders to be within call from
and after six o'clock, and, sir, it is already very near that hour."

"Now, I will tell you what to do, Salisky; you and your comrade here
take my car, report yourselves, and if it then be necessary for my
young friends to join you, return here for them. It is only the matter
of a very few minutes, either way."

Protesting under his breath, Salisky and his companion heard the
summons for the duke's automobile, and were whirled away in that swift
conveyance.

They could not understand the action of a company of imperial Cossacks
in ranging alongside of the machine, and only withdrawing when the
indignant chauffeur sent the machine forward with a vicious plunge.

An hour passed, and no word from the departed special messengers.

The boys walked with the duke through his magnificent gallery, but it
is doubtful if they had any high appreciation of the treat. In every
picture they saw a Cossack wrapped in a rainbow.

Finally, observing their inattention, and attributing it to anxiety
on their part at the committing of a breach of discipline, the duke
instituted inquiry as to the whereabouts of his chauffeur, intending to
forward the boys at once to Admiralty Place. Neither driver nor machine
could be found on the premises.

Billy felt that it was his turn to get into the figuring.

"It is such a fine evening, sir, and a straight way, that, if it is all
the same to you, Henri and I would like the exercise of walking back to
headquarters."

Henri could not fathom the scheme that his chum was nursing, but he
made no objection to the proposition.

The duke did not accompany the boys further than the door of the art
gallery, stating, with a grim smile, that he had always with him a
reminder of his fighting days in the shape of a "game leg." He gave
them both a kindly farewell and exacted a mutual promise of a longer
visit next time.

Behind the broad back of the flunky the lads proceeded as far as the
drawing-room, when Billy "happened to think" that he had left his
gloves in the dining-hall. There he looked for his missing gloves--out
of the window!

In the glow of the high-lights on the broad avenue were revealed the
gold-braided cavalrymen of the earlier hours, still patiently pacing
their horses up and down in front of the palace.

"Tell his nobs to see if the automobile has arrived," softly urged
Billy.

Henri sent the flunky ahead to investigate. He guessed now, and
correctly, that his chum did not intend that they should leave by the
front door.

Like ghosts they flitted through the dimly lighted corridors of the
palace, into the unknown backstairs regions, hoping to find an easy
outlet at the rear.

An open window coming handy, the boys essayed a jump therefrom, landing
on all fours in the walk leading to the tradesman's gate. Darting out
into a side street, the fugitives relapsed into a brisk walk, fearing
to here excite suspicion by undue haste.

Alone in a great and strange city, as ignorant of locality as of the
language spoken by the average inhabitant, Billy and Henri, as the
former would have put it, "were up against it, good and strong."

Yet they won out, and meeting the wildly searching special messengers
in the gray dawn, without ado climbed into the pilots' places of the
waiting biplanes and sent the powerful machines in whirring flight
toward the distant towers of Warsaw.

To follow them beyond this fixed destination is to turn the leaves of
the next record, under the title of "Our Young Aëroplane Scouts in
Russia; or, Lost on the Frozen Steppes."




       *       *       *       *       *




Transcriber's note:

The original text did not include a table of contents. One was created
by the transcriber.

Inconsistent hyphenation was retained.

Page 179, "though" changed to "thought" (I thought there was)

Page 239, "supposedlv" changed to "supposedly" (supposedly in waiting
in)