Produced by Juliet Sutherland, Ronald Holder and the PG Online
Distributed Proofreading Team







THE RADIO BOYS
ON THE
MEXICAN BORDER

BY GERALD BRECKENRIDGE

AUTHOR OF

"_The Radio Boys on Secret Service Duty_," "_The Radio
Boys with the Revenue Guards_," "_The Radio Boys'
Search for the Inca's Treasure_," "_The Radio
Boys Rescue the Lost Alaska Expedition_."

[Illustration: FRONTISPIECE]


A.L. BURT COMPANY

Publishers      New York




THE RADIO BOYS SERIES

A Series of Stories for Boys of All Ages

By GERALD BRECKENRIDGE

The Radio Boys on the Mexican Border

The Radio Boys on Secret Service Duty

The Radio Boys with the Revenue Guards

The Radio Boys' Search for the Inca's Treasure

The Radio Boys Rescue the Lost Alaska Expedition

By A.L. BURT COMPANY 1922

THE RADIO BOYS ON THE MEXICAN BORDER

Made in "U. S. A."



Table of Contents

FOREWORD

DIRECTIONS FOR INSTALLING AN AMATEUR RADIO RECEIVING TELEPHONE

CHAPTER I - A CRY IN THE AIR

CHAPTER II - THE ENEMY NEAR

CHAPTER III - A DARING LEAP

CHAPTER IV - SHOTS AT THE STATION

CHAPTER V - PLANS FOR THE FLIGHT

CHAPTER VI - A THIEF IN THE NIGHT

CHAPTER VII - KIDNAPPED

CHAPTER VIII - HELD FOR RANSOM

CHAPTER IX - ON THE DESERT TRAIL

CHAPTER X - A BRUSH WITH THE ENEMY

CHAPTER XI - JACK CANNOT SLEEP

CHAPTER XII - JACK DISCOVERS A TRAITOR

CHAPTER XIII - THE NET IS DRAWN TIGHTER

CHAPTER XIV - THE KEY TO THE MYSTERY

CHAPTER XV - TO THE RESCUE

CHAPTER XVI - A SOUND IN THE SKY

CHAPTER XVII - INSIDE THE CAVE

CHAPTER XVIII - THE FIGHT IN THE CAVE

CHAPTER XIX - RESTING UP

CHAPTER XX - CONFERRING BY RADIO

CHAPTER XXI - GAINING AN ALLY

CHAPTER XXII - FLYING TO THE RESCUE

CHAPTER XXIII - THE TABLES TURNED

CHAPTER XXIV - FRANK SAVES THE DAY

CHAPTER XXV - DANGER AT HAND

CHAPTER XXVI - THE NIGHT ATTACK

CHAPTER XXVII - SENORITA RAFAELA

CHAPTER XXVIII - THE FAIR TRAITRESS

CHAPTER XXIX - THREE CHEERS FOR THE RADIO BOYS

CHAPTER XXX - GOOD NEWS FOR ANXIOUS EARS

CHAPTER XXXI - CALM AFTER THE STORM

CHAPTER XXXII - MORE ADVENTURE AHEAD




FOREWORD


The development of radio telephony is still in its infancy at this
time of writing in 1922. And yet it has made strides that were
undreamed of in 1918. Experiments made in that year in Germany, and by
the Italian Government in the Adriatic, enabled the human voice to be
projected by radio some hundreds of miles. Today the broadcasting
stations, from which nightly concerts are sent far and wide across the
land, have tremendous range.

Estimates compiled by the various American companies making and
selling radiophone equipment showed that in March of 1922 there were
more than 700,000 receiving sets installed throughout the country and
that installations were increasing so rapidly it was impossible to
compute the percentage with any degree of accuracy, as the gains even
from week to week were great.

When you boys read this the problems of control of the air will have
been simplified to some extent. Yet at the beginning of 1922 they were
simply chaotic. Then the United States Government of necessity took a
hand. The result will be, eventually, that certain wave lengths will
be set aside for the exclusive use of amateurs, others for commercial
purposes, still others for governmental use, and so on.

In this connection, you will note that in the story Jack Hampton's
father builds sending stations on Long Island and in New Mexico. This
is unusual and requires explanation.

The tremendous growth of amateur receiving stations is due in part to
the fact that such stations require no governmental license. A sending
station, on the other hand, does require a license, and such license
is not granted except upon good reasons being shown. It would be
natural for the government, however, to give Mr. Hampton license to
use a special wave length--such as 1,800 metres--for transoceanic
radio experiments. Extension of the license to the New Mexico plant
would follow.

THE AUTHOR.




DIRECTIONS FOR INSTALLING AN AMATEUR RADIO RECEIVING TELEPHONE


In order that the boy interested in radio telephony may construct his
own receiving set, the Author herein will describe the construction of
a small, cheap set which almost any lad handy at mechanics can build.
Such a set should be sufficiently powerful to permit of successfully
picking up the concerts and other programme entertainments being
broadcasted frequently by stations throughout the country.

Two drawings are given herewith which will enable boys to visualize
the appearance of the set, and will be of aid in following
instructions.

Referring to Figure 1 let us examine first the construction of the
receiving inductance marked L. The latter is shown in detail in Figure
2, and consists of a heavy piece of cardboard. The back of an ordinary
writing pad will do.

[Illustration: Figure 1]

First, draw the circle out with a compass to the diameter shown and
then divide off the outside into an unequal number of divisions as
shown. Draw a light pencil line through each of these marks to the
centre of the circle. Now with your scissors cut out the disc, after
which you cut the slots as shown.

The slots should be about one-quarter of an inch in width and of the
depth shown in the drawing. Two such discs should be made and, when
all cut out, should be given several coats of shellac to add stiffness
and to improve the insulating qualities.

Now at your hardware dealer's buy one-quarter pound of No. 24 double,
cotton-covered wire and proceed to wind the coils in the manner shown.
Keep the windings even and avoid all joints throughout the length of
winding.

When you have finished, mount the coils as shown in the drawing. Make
sure that the windings on both coils run in the same direction. If you
fail to do this, the set will not work.

For the detector, it is better to purchase a good make of galena
detector at any radio supply store. If you are handy with tools,
however, you can buy the galena and make your own detector. It will
work with more or less satisfaction.

Your next need will be the condenser. The condenser consists of a
series of aluminum plates, some of which are movable and the rest
stationary.

Buy a small variable condenser. Its function is to tune the secondary
circuit, which is accomplished simply by turning the knob. Such a
condenser could not be made without the use of a good set of tools,
and the author strongly advises it be bought instead of made at home
in order to avoid trouble. The aluminum plates are spaced very closely
and great care should be taken to avoid bending them, as they must not
touch each other.

The aerial for this set should be about 60 to 100 feet in length and
as high and clear of surrounding objects as possible. A simple
porcelain cleat at either end, as shown in the drawing, will serve to
insulate it sufficiently.

Your ground connection can be made best by wiring to the cold water
pipe, although wiring to a steam or gas pipe will do almost as well.

You are now prepared to mount the various instruments in their proper
locations. For your table instruments, get a good pine board about
seven-eighths of an inch thick. Buy four binding posts and use one for
the aerial wire, one for the ground wire, and two for the phones or
head set.

To operate the set, first bring the hinged coil of wire close up to
the fixed coil and adjust the detector until you can hear in your
receivers the loudest click caused by the turning on and off of the
key to a nearby electric light. If no light is available, a buzzer and
dry battery should be used. When the detector is properly adjusted you
will be able to hear the buzz quite distinctly in the head phones if
the buzzer is not too far away.

[Illustration: Figure 2]

The actual adjustment of the detector is rather a delicate job, and
once it is in the proper position it is a good plan to avoid jarring
it, as it is liable to get out of adjustment very easily.

Once the sensitive spot on your detector is found, slowly turn the
knob on your condenser and at some spot on it you should be able to
pick up signals of some sort, either of radiophone or spark. If the
set does not work, then go over all your wiring and be sure that the
windings of the two coils are both running the same way.

The above set will work well for short distances, say up to twelve or
fifteen miles. Beyond that, however, it will not receive music unless
you have unusual facilities for putting up an aerial to a considerable
height and well clear of surrounding objects.

Such a set should be constructed at a minimum of cost and may later,
after you have become familiar with the operation of radio appliances,
easily be converted into a set of much greater range by the use of a
vacuum tube as detector and may even, by slight changes, be given the
much desired regenerative effects.




CHAPTER I

A CRY IN THE AIR


"Well, Bob, here we are again. And no word from Jack yet."

"That's right, Frank. But the weather has been bad for sending so
great a distance for days. When these spring storms come to an end the
static will lift and well stand a better chance to hear from him."

"Righto, Bob. Then, too, the Hamptons may not have finished their
station on time."

The other shook his head. "No, Jack wrote us they would have
everything installed by the 15th and that we should be on the lookout
for his voice. And when he says he'll do a thing, he generally does
it. It must be the weather. Let's step out again and have a look."

Taking off their headpieces, the two boys opened the door of the
private radiophone station where the above conversation took place and
stepped out to a little platform. It was a mild day late in June, and
the sandy Long Island plain, broken only by a few trees, with the
ocean in the distance, lay smiling before them. A succession of
electrical storms which for days had swept the countryside in rapid
succession apparently had come to an end. The clouds were lifting, and
there was more than a promise of early sunlight to brighten the
Saturday holiday.

The boys looked hopefully at each other.

"Looks better than it has for days, Frank."

"That's right."

A few moments more they chatted hopefully about the prospects, then
re-entered the station.

Frank Merrick and Bob Temple were chums, a little under 18 years of
age each. It was their bitterest regret that they had been too young
to take any part in the World War some years before. Frank was dark,
curly-haired, of medium height and slim, but strong and wiry. Bob was
fair and sleepy-eyed, a fraction under six feet tall and weighed 180
pounds. A third chum and the leader of the trio was Jack Hampton, 19
years of age. He had gone to New Mexico several months before with his
father, a mining engineer.

All three boys were sons of wealthy parents, with country estates near
the far end of Long Island. Frank's parents, in fact, were dead, and
he lived with the Temples. Mr. Temple was his guardian and
administrator of the large fortune left by his father, who had been
Mr. Temple's partner in an exporting firm with headquarters in New
York City. Jack Hampton also was motherless.

The boys were keenly interested in scientific inventions, and were
given every facility by Mr. Temple and Mr. Hampton for indulging their
hobbies. Such indulgence required considerable sums of money, but the
men believed the boys were worth it. In fact, both gentlemen were
scientifically inclined themselves, and were able to give the boys
much valuable advice.

When Mr. Hampton decided to go to Texas and New Mexico as the
representative of a group of "independent" oil operators engaged in a
bitter war with the Oil Trust known as the "Octopus," Jack begged so
hard to be permitted to go along that his father let him quit
Harrington Hall Military Academy two months before the end of the
term.

It was agreed that when school ended, June 28, Frank and Bob should
join Jack in the Southwest for their summer vacation. The two boys
owned an airplane in which they hoped to make the trip when the time
came. Mr. Temple, however, was dubious about letting them attempt to
make so long a flight alone.

"But, Dad," Bob would argue, whenever the matter was discussed, "we'll
be all right. We've made lots of flights without any accidents. We're
as capable as anybody. You know yourself what the instructors up at
Mineola told you. You say we are too young to fly away alone. But look
at the young fellows that got to be 'aces' in the War! Not much older
than we are now."

It must be confessed that Mrs. Temple thought little of the matter one
way or the other. She had so many social duties to take up her time
that there was little left for the boys. Accordingly, the boys had
only Mr. Temple to persuade and they felt pretty certain of doing that
in time. So the last two months of school were spent in poring over
maps and routes, and in studying up on landing fields and flying
conditions generally throughout the territory they would have to
cover.

Much of this study for the proposed flight was carried on at the
radiophone station on the Hampton estate. Mr. Hampton was an
enthusiast about the development of radio telephony and it was through
him the boys first had become interested in the subject. A year
earlier he had built a powerful station for the purpose of making
experiments in talking across the ocean. On that account the United
States Government had granted him a special permit to use an 1,800
metre wave length.

Before leaving for the Southwest, Jack told the boys his father
intended to build in Texas or New Mexico another radiophone station of
similar wave length. This would enable Mr. Hampton to communicate
with his New York confreres through his Long Island station. The big
thing to the boys, however, was that they would be able to talk to
each other across 2,000 miles of territory. Delays in construction in
the Southwest had occurred, however, and communication between the two
stations had not yet been established when our story opens.

As the boys re-entered the station after their inspection of the
weather, Bob threw himself sprawlingly into a deep wicker chair and,
picking up a book, began idly to turn the pages. Frank went to the
table where the control apparatus was located and put on a headpiece.
For a few moments there was silence, which Frank presently shattered
with a loud cry of: "Bob. Bob. Come here."

Bob dropped his book and, leaping to his feet, strode to his chum's
side.

"What is it?"

"Put on a headpiece, Bob," said Frank in a voice of great excitement.
"I believe Jack is trying to get us."

Excited as his chum, Bob clamped a receiver on his head, while Frank
manipulated the "amplifier" and "detector" knobs on the control
apparatus.

A variety of sounds greeted the boys at first, whistles, calls, and
chattering coming to their ears. Then as their tuner searched out the
higher regions of the air, they shut out the sounds of the low-range
air traffic. There was a thin, shrieking sound. Then, that also
disappeared. And then quite suddenly the listening, expectant boys
heard Jack's voice speaking to them just as plainly as if he stood in
the room.

"Frank. Bob. Bob. Frank," Jack was saying. "Can you hear me? Can you
hear me?"

"Hurray, Jack, sure we can hear you," cried Frank, bending forward to
speak into the transmitter on the stand before him.

Then as Jack's voice continued calling without paying him any
attention, he straightened up and laughed.

"Gee. I forgot," he laughed. Laying down his headpiece, he ran across
the room; opened a door into the power house adjoining where the
mechanic was dozing over his pipe and called to him to throw on the
generator.

Galloping back, as the man obeyed, Frank again snatched up his
headpiece. Bob already was bending over a transmitter, calling to Jack
in faraway New Mexico. Both boys listened with straining ears for the
response. Presently Jack answered: "I can hear you, but only very
faintly. Put that band piece on the talking machine. You know the one
I like so much. I can't think of its name. I'll tune to it."

Frank hastily shuffled through a pile of talking machine records.
Finding the one he sought, he put it on the machine which stood
directly in front of a big condensing horn strapped to the back of a
chair to give it the proper height. A moment or two later, Jack's
voice in the receivers declared:

"All right. Shut her off now. I'm fixed fine."

"Say, Jack, think of talking 2,000 miles like this," said Bob.

"Oh, we've been working some days out here," answered Jack. "But we
couldn't get you."

"No," cut in Frank. "The static interfered, I guess. But it lifted
today."

"How are things going, Jack?" Bob inquired next.

Jack's voice became excited. "Going?" he answered. "Fellows, I never
knew what excitement was until this last week."

"What do you mean?" demanded both boys together.

"Oh, I couldn't tell you now," laughed Jack. "It would take all day
and then some to tell you all that's happening around here. But, let
me tell you, between Dad's business opponents and a gang of Mexican
bandits that appeared on the scene lately, things are getting pretty
lively. Say, when are you coming? Now's the time if ever----"

Suddenly, Jack's voice ceased abruptly, to be succeeded a moment later
by his agonized cry for "Help." Then there was a crash that rang in
the eardrums of the alarmed boys listening in. Then, silence.

"Jack. Jack," they called. "What's the matter?"

There was no answer.




CHAPTER II

THE ENEMY NEAR


Frank Merrick and Bob Hampton looked at each other in alarm. Their
faces were pale.

That cry for "Help" which abruptly had cut off Jack's voice as he
spoke to them from his radiophone station 2,000 miles away in New
Mexico still rang in their ears. Their heads still hummed from the
vibrating crash which had succeeded. What did it all mean?

Frank snatched the receiver from his head, while Bob removed his more
slowly. Frank voiced the question in each mind as he said in a tone of
apprehension:

"What do you think happened to Jack?"

"You know as much as I do," answered his chum.

"Well, do you know what I think?" asked Frank with energy. "I think
those Mexican bandits he spoke about sneaked up on him."

"Well, if they did, they caught a Tartar," said Bob, with conviction,
remembering Jack's athletic prowess. All three boys were athletic,
good swimmers, boxers and wrestlers, as well as skillful fencers.
Jack, however, was unquestionably the superior of the others, except
that Bob was the best wrestler.

Frank shook his head dubiously. "I don't know," he said. "If there was
a bunch of them and if they sneaked up from behind while he was
talking."

"Just the same," said Bob, "old Jack would put up some battle. I'll
bet you the furniture got mussed up all right, all right. That's the
reason for that crash. Probably the microphone was torn from the
cords. They may even have wrecked the station. Boy, oh boy, don't I
wish I'd been there." And Bob doubled up his fists and pranced around,
making deadly swings at imaginary foes.

"Calm down, Bob," said Frank, dropping into a chair and running a hand
through his hair as he was in the habit of doing when perplexed. "We
don't know that it happened the way we figure. We don't know what
happened. Maybe Jack was badly hurt, maybe he was killed. Or he may be
a prisoner of the bandits.

"Oh," he cried, leaping to his feet and beginning to walk up and down
the room distractedly, "isn't there something we can do? This is
maddening."

"Calm down yourself, Frank," said Bob, always the cooler of the two in
a crisis. "If we can't do any better, at least we can wire to Jack's
father and find out in a few hours what happened."

At this moment the door was pushed open. A tall man of distinguished
appearance, still in the prime of life, and bearing a close
resemblance to Bob, entered the room. He glanced inquiringly at the
boys.

"Something gone wrong?" he asked. "What's the trouble?"

"Hello, Dad."

"Hello, Uncle George."

It was Mr. Temple, Bob's father and Frank's guardian, and there was
relief in the boys' voices as they greeted him. He always was so
capable in an emergency.

"Motored home at noon today," he said. "Guess I've got spring fever.
Anyhow, I couldn't stand it in the city. Della told me you were over
here and that you thought, perhaps, you would hear from the Hamptons
today." Della was Bob's younger sister, and the Temples' only other
child.

"We heard all right, Dad," said Bob gravely. Thereupon he proceeded to
relate what had occurred.

Mr. Temple listened in silence. His face showed he was disturbed. At
the conclusion of Bob's recital, he walked over to a headpiece and put
it on.

"No use, Uncle George," said Frank, but Mr. Temple turned to him with
a twinkle in his eye.

"That so?" he said.

With a cry, Frank leaped from his chair, seized a headpiece and put it
on.

"Hurray, it's Jack," he shouted. Then he bent over to the telephone
and called:

"Jack. Jack. Are you hurt? What happened?"

"Oh, I'm bunged up a little," came back Jack's voice, in a cheerful
tone. "But there are no bones broken."

"Was it the bandits?" demanded Bob, who had clamped on a third
headpiece, as he elbowed Frank aside to speak into the transmitter.

"Yes. Three of them," responded Jack. "A scouting party. They sneaked
in behind me. Thought I was alone, I guess, but when I hollered for
help Dad came in from the power house on the run and the pair of us
put them down for the count. We've got them tied up here now. The
microphone cord was snapped but I was able to make repairs. So I
started calling for you right away."

"Jack, this is Mr. Temple," cut in the older man at this point. "If
your father is there, please put him on the phone. I'd like to speak
to him."

"All right, Mr. Temple," answered Jack. "He's right here. Wait just a
minute."

Frank and Bob politely removed their headpieces and walked to a
bookcase, talking in low tones, as they leaned their elbows on the top
of it. This room, by the way, deserves a brief description.

It was circular and without windows. The walls were hung with a
material resembling burlap in appearance, but of special construction
and sound-proof. The ceiling was nine feet high. From a point six feet
up the walls material like that in the walls stretched to a point in
the middle of the ceiling. The room had somewhat the appearance of the
interior of a small circus tent. This construction was for the purpose
of increasing the acoustic properties.

While Mr. Temple conversed with Mr. Hampton, in whose oil operations
he naturally was interested, as he had invested a considerable sum in
them, the boys talked in whispers. They were frankly envious of Jack's
adventures and wishing that they, too, were on the ground. Suddenly,
something said by his father caught Bob's attention, and he stopped
talking to Frank and turned to listen.

"Well, I'll tell you, Hampton," Bob heard his father say, "I've got a
sharp attack of spring fever. I think I need a vacation. And if these
two youngsters of mine will let me go along, I'll come out with them."

Bob couldn't control his eagerness. Going up to his father's side, he
pulled insistently at his sleeve.

"Wait a minute, Hampton," said Mr. Temple. "Bob has something on his
mind." He removed the receiver and regarded his son with a twinkle.
"Out with it," he said. "I suppose that quite shamelessly you've been
listening to my conversation."

"No, Dad, Honest Injun," protested Bob. "Only I couldn't help
overhearing that part about you going with us. Say, Dad, we'll go by
airplane, won't we?"

Mr. Temple groaned in mock dismay. "Run along," he said. "You'll drive
me crazy with that airplane business." Then, once more adjusting his
headpiece, he resumed his interrupted conversation with Mr. Hampton.

Bob returned to Frank, wearing a wide grin. "I couldn't resist putting
over that piece of propaganda," he said.

"Do you think he'll let us fly?" whispered Frank.

"Say," answered Bob scornfully, "now that Dad has decided to go along,
it's a cinch. He's as crazy about flying as Mr. Hampton is about the
radiophone."

"Ssst. Ssst," came a warning whisper, interrupting them. They swung
about to face the door into the power house. It was part-way open and
the round good-natured face of Tom Barnum, filled now with anxiety,
was framed in the opening. Tom was the mechanic-watchman. He beckoned,
and the boys tiptoed across the room and into the power house, closing
the door behind them. Old Davey, caretaker at the Hampton home, stood
there, wringing his hands.

"What is it? What's the matter?" Frank Merrick asked sharply.

"Old Davey says there's a thief up at the house," said Tom.

"A thief?" said Bob. "How do you know?"

"Seed him myself with my own two eyes," quavered Old Davey, a little
old man who was a pensioner of Mr. Hampton's. "He's a big dark
ugly-lookin' feller. I seed him a-sneakin' into the house through the
cellar door I left open to git out some garden tools."

"Then what did you do?" asked Frank.

"I run," said Old Davey, simply. "Leastways I tried to, but my legs
ain't what they used to be."

"Come on, Bob," said Frank, impulsively. "Let's go see."

"Not till we tell Dad, first," said Bob, as always the cooler.

Re-entering the sending room, Bob once more gained the attention of
his father, who still was in conversation with Mr. Hampton. He told
him what Old Davey had reported. Mr. Temple readjusted the headpiece
and swung about to the transmitter.

"Anything in your house a fellow could carry off in a pocket,
Hampton?" he said. "Because the boys tell me there is a thief in it
right now, and we're going up to try to catch him."

"I don't think so," said Mr. Hampton, and then added in a tone of
alarm: "Great guns, Temple, yes. There is. There's a duplicate list
among my papers that the Octopus would give anything to obtain
possession of. It's a list of the lessees out here in the oil fields
who have joined the independents."

"All right, Hampton," said Mr. Temple, "we're off."

Removing the headpiece, he hurried Bob back into the power house.
There he ordered Tom to switch off the motor, lock up and follow them.
Then accompanied by the boys and with Old Davey trotting alongside to
keep up, he started in swift strides for the Hampton house, which
could be seen above the intervening tree tops, about a quarter of a
mile away.

"I thought you came out from town for a little peace and quiet, Dad,"
said Bob. "You're certainly getting it, aren't you? Hey. There he
goes." And with a shout, Bob started running swiftly toward the figure
of a man who had just emerged from the open cellar door at the rear of
the Hampton house.




CHAPTER III

A DARING LEAP


At Bob's shout the intruder who had just emerged from the Hampton
cellar looked back over his shoulder. Seeing he was discovered he
broke into a desperate run. He was heading toward the front of the
house where ran the long and winding drive which led to the main
highroad.

The man shouted hoarsely, and from the front of the house came the
sound of a powerful motor engine being set in motion.

"He's got a car waiting for him," cried Bob, who was in the lead.
"Drat the luck, he'll escape us yet."

"Hey, Bob, we can cut 'em off at the Gut," called Frank, and he struck
away at a tangent from their course as the man disappeared around the
house and the motor car could be heard roaring off down the drive.

"Righto," cried Bob, and he followed his chum.

Old Davey had dropped far behind and Mr. Temple and Tom Barnum were
laboring along some yards in the rear of the two boys and steadily
losing ground.

"Careful, boys," called Mr. Temple gaspingly, as he grasped the
meaning of the boys' maneuver. "Don't be rash. May be several of
them."

"All right, Dad," sang out Bob over his shoulder. "We'll be careful.
Follow along."

The boys were heading for a place in the woods where the drive ran
between six-foot banks before turning a sharp corner. Cars perforce
had to be slowed up going through this place which the boys called the
Gut. Furthermore, the drive approached this place by a winding,
circuitous route, while the boys were not far distant from it by the
shortcut through the woods which they were following. Chances were
even that they would be in time to intercept the fugitives. Yet what
could they do even if they arrived in time? They gave no thought to
that as they crashed through the underbrush.

Bob slightly in the lead reached the top of the bank overhanging the
road ahead of his comrade and experienced a thrill of triumph as he
heard the roar of the approaching car and realized he had arrived
first. The car slowed down as it entered the Gut. Evidently the driver
remembered the perilous place from when he had driven through on
approaching the house.

The car passed below going at a snail's pace while Frank was still a
short distance in the rear and Mr. Temple and Tom Barnum were not yet
in sight. It was an open touring car with the top folded back. There
were three men in it, one on the seat beside the driver and the third
in the rear. He was the man who had entered the Hampton house. The
driver appeared to be a New York taxi chauffeur, and probably had been
employed for the trip. The others were swarthy men, foreign in
appearance.

The man beside the driver, looking up, saw Bob, and shouted. At that
moment the car passed directly beneath him, and Bob leaped. He landed
on the running board beside the rear seat. Steadying himself as the
car lurched from the impact of his weight, Bob reached in and grasped
the man on the rear seat by the coat collar and half pulled him from
the car, so that his body lay across the door.

Then the unexpected occurred. The driver opened his throttle and the
car leaped ahead, and at the same time the man beside him stood up and
struck at Bob.

Bob leaned back to avoid the blow, and the next moment found himself
flat on his back in the road, with the car disappearing around the
curve.

Frank, who by now had reached the top of the bank, dropped to the road
beside him and bent over him with real anxiety in his voice as he
said:

"Bob, Bob, are you hurt?"

Ruefully rubbing the back of his head, Bob sat up.

"No," said he, "But they got away, Frank."

Again there was a crashing in the underbrush on the top of the bank,
and Mr. Temple and Tom Barnum came into view, red and perspiring.

"Escaped you, hey?" said Mr. Temple, leaping to the road, as Bob
scrambled to his feet. "But, say, I see you captured something all
right." And he pointed to a coat clutched fast in Bob's hand.

Then for the first time Bob noticed that in falling from the car he
had dragged his victim's coat with him. He held it up and looked at it
curiously.

"He must have been wriggling out of his coat when he found you
wouldn't let go," surmised Frank. "I could see him threshing around
just as I came up to the top of the bank. Then you fell and held on
tight and the coat was pulled from him."

"Yes, I guess that's the way it happened," assented Bob. "Well, I'd
rather have had the fellow. This isn't any good to me." And he tossed
the coat away contemptuously.

"Not so fast, Bob," said Frank, stooping to pick up the garment.
"Let's see what's in the pockets. There may be a clue as to the man's
identity."

"That's right, Frank," said Mr. Temple. "Search it well. And, Bob, did
you notice the license number of the car? We can telephone and have it
intercepted."

"No," confessed Bob. "I was too busy to get that."

Frank interrupted the conversation with a shout of delight. "Look at
this," he cried, holding up a long strip of paper. "Return trip ticket
to Ransome, New Mexico. And a wallet with a big bunch of bills in it.
And here, what's this?" he added, holding up a thick, legal-looking
envelope. "Why, Mr. Hampton's name is written on it."

"Let me have that, Frank," said Mr. Temple, extending his hand. Frank
passed him the envelope. Mr. Temple noted the seal had been broken,
and opening it he pulled out a thick document down which he ran his
glance hurriedly. Then his face became grave.

"Boys," he said, "Mr. Hampton has many things of value in his home,
but this was the most valuable of all." Briefly he explained the paper
contained a list of names of "independents" in the oil field, together
with other information, which would give the Octopus a very great
advantage in the business war between the Oil Trust and the
"independents" if the document fell into its hands.

"This is pretty serious business, boys," Mr. Temple continued. "Bob,
you were very rash, but you did a good stroke of business that time.
Come," he added, "we'll go back to the house, and call up the police.
Maybe that car can be stopped and its occupants arrested."

As they turned through the woods, another thought occurred to Mr.
Temple, and he asked Frank what was the name of the man to whom the
railroad ticket had been issued.

"Jose Morales," read Frank. "This is the portion for the return trip
from New York. Evidently the man came from--why, Mr. Temple, he came
here from Ransome, New Mexico. That's the nearest station on the
railroad to the Hampton's camp."

"You're right, my boy," said Mr. Temple gravely. "There is some
mystery here."

Frank thwacked Bob gleefully on the back. "Say, Bob," he declared,
"old Jack isn't having all the fun after all, is he?"




CHAPTER IV

SHOTS AT THE STATION


"Boys," said Mr. Temple, when the Temple home, a short distance from
the Hampton place, was reached, "come into the library with me. I want
to have a serious talk with you."

Obediently, Bob and Frank filed into the room and sat down in deep
leather armchairs, while Mr. Temple sat back in a swinging chair by
his broad, flat-topped desk. Selecting a cigar from the humidor at his
elbow, he lighted it and puffed thoughtfully several moments before
addressing the chums.

"First of all," he said at the conclusion of this period of silence,
"I've decided that we will not notify the police of this affair."

"Why not, Dad?" demanded Bob in surprise.

"We want to keep this matter to ourselves until we can see more
clearly what it means," explained Mr. Temple. "We recovered what was
stolen, anyhow. But more than that, I begin to suspect there is
something more behind all this than mere business rivalry between the
independent oil operators and the Trust."

"What do you mean, Uncle George?" asked Frank, puzzled.

"Well, boys, I'll tell you," said Mr. Temple, speaking deliberately
and thoughtfully. "In the first place I know the men at the head of
the so-called Octopus. They are keen business men and quick to seize
every legitimate advantage. But they are above such unscrupulous
tactics as this.

"I know the signs point to them as the instigator of our troubles at
Mr. Hampton's camp and then here today. But those signs point to
something else, too. If you will recall, Jack said the fellows who
raided the Hamptons today, or rather tried to do so but failed, were
Mexicans. And this man who entered the Hampton house today was a
Mexican, too. What was his name, Frank?"

"Morales. Jose Morales," said Frank, promptly.

"Yes, Jose Morales," said Mr. Temple. "Well, I believe that certain
Mexicans are responsible for our troubles, and not our business
rivals, at all."

"What in the world?" said Bob, puzzled.

"But why, Uncle George?" demanded Frank.

"In order to make trouble between the United States and Mexico," said
Mr. Temple, promptly.

"Oh," said Bob, "I begin to see what you're driving at. You mean,
then, that by attacking the independents in the Southwest these
Mexicans would get us so stirred up that Uncle Sam would take a hand
to protect our properties, and might even send troops to the border?"

"That's exactly what I mean, Bob," said Mr. Temple approvingly.

"But in that case, Uncle George," demanded Frank, "why wouldn't the
Mexicans be making trouble for the Octopus, too?"

"Because, Frank," explained the older man, "the properties throughout
the region where we are located are mainly held by independent
operators. The Octopus is trying to gobble us up, but it hasn't
succeeded, and won't if we can prevent. But, just the same, it isn't
there for the Mexicans to attack. If they want to harass anybody in
the hope of getting the United States Government to intervene, they
must attack us and our friends and allies."

"Yes, I see that now," said Frank, nodding. "But what makes you think
the Mexicans want to get into a war with Uncle Sam?"

"They don't particularly yearn to come to blows with us, Frank," said
Mr. Temple. "And not all Mexicans are involved, if my suspicions are
correct, but only a faction. You see, boys, General Obregon has been
President of Mexico now for several years, but the country is far from
pacified and far from submitting to his rule. The rebel forces in the
northern part of Mexico are gaining in strength right along. One of
these days they will be in open revolution.

"Now these Mexicans who want to depose Obregon would like to get him
into trouble with the United States in the hope that what they desire
would then come to pass."

"I begin to understand you," said Bob, with more animation than usual.
"You mean the rebels would like to stir up trouble on the border and
get Obregon into hot water with Uncle Sam in just the same way that
Pancho Villa some years ago made trouble between our government and
Carranza by his raid on Columbus, New Mexico?"

"That's it, Bob," said his father.

"Gee, Dad," cried Bob. "This time, if there's a war, I'm going to
enlist, believe me."

"Same here, Uncle George," declared Frank. "Bob and I could go as
aviators."

"Hurray for the young aviators of the Rio Grande," cried Bob, swinging
his arm like a cheer leader of the school team.

"You boys don't know what you're talking about," said Mr. Temple, but
with an indulgent smile. "I should imagine you would have read enough
of the horrors of war during the past few years to make you never want
to see a battlefield or shoot a gun at a man."

"That's right, Uncle George," said the sensitive Frank, shuddering as
he recalled some of the things he had read of Europe's devastation.

"No, boys," said Mr. Temple, "if I am right about this, we'll have
something more important to do than to fight battles or track bandits
across the Mexican desert by airplane."

"What?" chorused the chums.

"Instead of making war," said Mr. Temple slowly, "we'll have to
prevent it."

"Righto, Uncle George," cried Frank, springing up. "When do we pack?"

"Young man, you're in a hurry, aren't you?" smiled Mr. Temple. "Well,
boys, I believe that by day after tomorrow I can have my affairs in
order so that I can leave them for awhile. Then we'll start. That is,
of course, if you'll carry me as a passenger."

"Will we carry him?" said Bob, striding to his side. "Good old Dad."
And he thumped his father on the shoulder, a resounding blow that made
the older man grimace humorously and draw away from him.

They were interrupted by a knock on the door. Frank opened the door to
find a maid standing in the passage. She was trembling with
excitement.

"Oh, Mister Frank," she gasped. "I heard several shots. Seemed like
they came from the radiophone station of Mr. Hampton's. I'm so worried
about Tom."

"That's right, Tom's your sweetheart, isn't he?" said Frank. The maid
blushed. Frank re-entered the room, and explained the maid's message
practically all in one breath.

"We were talking so much that we didn't hear the reports, I suppose,"
said Mr. Temple, jumping up and snatching at his hat. The boys already
were at the door but he called them back. "This time," he said grimly,
"I'm not going to have you taking any chances on being killed. You
will wait for me, and please remember it." Opening a drawer, he drew
out a heavy automatic, broke it open to assure himself it was loaded,
and then dropped it in his coat pocket. "All right now," he said.
"Let's go."




CHAPTER V

PLANS FOR THE FLIGHT


The boys needed no second bidding. Out of the door, down the
passageway, and out of the house, they dashed. Then they headed across
an intervening stretch of lawn for the radiophone station, concealed
from sight by a clump of trees. Mindful of Mr. Temple's admonition not
to rush into danger without him, they checked their pace. But the
older man was making good time himself.

Through the woods they dashed, emerging within sight of the door of
the power house. There stood Tom Barnum unharmed, revolver in hand. At
the noise of their approach, he swung about abruptly, bringing up his
revolver in doing so. Mr. Temple and the boys shouted, and he dropped
the threatening weapon again to his side.

"Thought they were comin' back," he said.

"What happened, Tom?" queried Mr. Temple, as they surrounded the
watchman-mechanic in charge of the Hampton radiophone station with
whom they had pursued a thief fleeing from the Hampton home only a
short time before.

"Well, sir, when we come back from chasin' them fellers in the motor
car," Tom explained, "I stopped at your back door a minute to chin
Mary an' tell her the news. She wanted to know what all the excitement
was about.

"Then I come on down here, an' thinks I to myself: 'I'll just get out
the old army revolver that I carried in France an' I'll be better
fixed for trouble the next time.' So I took 'er out of my locker in
the shop here an' swabbed her up an' just got everything slicked when
I hear a fellow creeping up to the door an' then voices whisperin'
together.

"Then the door starts to open slow an' easy like. I seen somebody what
hadn't no business here was nosin' around an' I says to myself: 'Tom,
it's a good thing you got the ol' army gun fixed up in time.'

"Then one of 'em stumbles an' falls agin the door an' open she comes
with him a-sprawlin' on the floor. The other fellow is right behin'
him but he sees me an' lets out a yell an' turns an' runs. Man, he was
a regular jackrabbit, too. I'll say that for 'im.

"Well, I been crouchin' by the dynamo an' let out a screech like wild
Injun an' fired off a shot through the doorway. Maybe two shots. Say,
you'd oughta seen that bird fly then. As for the other fellow, the one
that stumbled an' fell, he picks himself up an' tuk out like a
whitehead.

"I fired agin, high, just to scare 'em. I scared 'em all right, I
guess. Anyhow, they disappeared over south there toward that old wood
road that nobody uses no more. An' then I hear a motor car roar an'
off she goes."

"Why," cried Frank, "they must have been the same two men we chased."

"Were," said Tom. "Dark-lookin' fellers an' one didn't have no coat.
That was the guy Bob peeled his coat off of. I'd know 'em agin easy."

For several minutes there was an animated discussion of the exciting
events of the afternoon. What puzzled Bob and Frank was the reason for
the return of the thieves to the scene from which they had been
driven. Nobody could offer a good solution of the mystery until
finally Bob said:

"Say, I'll bet they were going to hide here in the station and lay for
me in the hope of getting back that coat and the papers the thief
stole from Mr. Hampton's house."

"Yes," put in Frank, "and the wallet with the railroad ticket to
Ransome, New Mexico, and all that money, too."

"I believe you are right, boys," said Mr. Temple. "These certainly are
no ordinary thieves, but desperate men."

Tom had re-entered the power house and was pottering around the
machinery.

"Dad," said Bob, who had been knitting his brow in thought,
"according to what you believe, this is all part of a plot of certain
Mexicans to embroil their country and ours by making trouble for the
independent operators in the Southwest represented by Mr. Hampton. In
that case, why should they try so hard to steal that list of the names
of the independents. That looks to me like a move on the part of your
business rival, the Octopus."

"I know it does, Bob," said his father. "The thing isn't clear to me
by a good deal. But I believe I am right. However, let's go into the
station now and call up the Hamptons out in New Mexico. Both Mr.
Hampton and Jack will be interested to hear about what has happened
here this afternoon."

The boys agreed enthusiastically, and with a word to Tom Barnum to
switch on the motor in order that they might have power to telephone,
all three entered the station. But, despite repeated calls, they
received no response.

"I suppose there's nobody at their station, that's all," said Bob.

"I suppose so," said his father. "But this business has me worried.
Let's hope nothing has gone wrong out there."

Reluctantly, all three abandoned their efforts, removed their
headpieces, and with a "good-bye" to Tom, who lived in a room at the
rear of the station, started for the house. If New Mexico were to
call, a light bulb would flash the signal in Tom's quarters, and he
would telephone the house.

It was twilight when they reached home, and all three went to their
rooms to dress for dinner.

"Tomorrow," said Mr. Temple in parting, "we'll all drive over to
church, and then in the afternoon you boys can go to work preparing
the airplane, and I'll lend a hand." Mr. Temple was chairman of the
Board of Trustees of an old ivy-covered church in a sleepy village
some miles away, and never let Sunday pass without attending divine
worship.

At dinner the talk was all of the prospective airplane flight to New
Mexico. The events of the day were told in detail to Mrs. Temple and
Della, Bob's sister. Della, who was an athletic girl of 16, declared
she wanted to go with them, but Bob answered rudely, as boys too often
speak to their sisters:

"Huh," he said, "you'd just get in the way."

Mrs. Temple made no objections to the proposed trip, but began
immediately to lay plans for filling the house with guests during
their absence. And in discussion of the details, Della was appeased.

"Say, Bob, why are you so rude to Della?" Frank queried later, in the
library, as they awaited Mr. Temple's coming to discuss preparations
for the flight.

"Huh, she's not your sister, Frank," said Bob. "Anyhow, I believe
you're sweet on her."

"No, I'm not," said Frank hotly, "but she's a good kid and you ought
to treat her better."

"Yes, you are, too," said Bob. "I know you. But there's no use getting
hot about it. Here comes Dad now," he added, as a familiar footstep
sounded in the hall. "Let's get at those maps and guides and we'll
dope this out together."

For several hours the discussion continued. For months the boys had
been making their plans, going over routes, selecting landing fields,
etc. Now that Mr. Temple had decided to accompany them, they laid
their plans before him. He nodded, well satisfied in the main, but
making a few pointed suggestions of value.

"And with the radiophone that we carry on the airplane," said Frank,
"we can be in touch with Tom at this end and Jack out in New Mexico
all the way. That all-metal body of the plane makes a fine ground,
better than hanging wires possibly could. And with that new detector
Bob and I have worked out, I'll bet we can hear all the way."

"Sure," said Bob, getting up and stretching, "Well, come on, Frank.
Let's turn in. It's near midnight. I for one need a good night's
sleep. And I hope there'll be no trouble to disturb us tonight."

Alas, poor Bob could not foresee what calamity the night held in
store.




CHAPTER VI

A THIEF IN THE NIGHT


"Wake up, Bob, you old sleepyhead."

Bob stirred under vigorous shaking, opened his eyes sleepily, and saw
Frank bending over him. His chum had thrown a bathrobe over his
pajamas. The door between their connecting rooms stood open. The early
morning sunlight of a bright June day streamed in the open windows.

"Whazzamatter?" grunted Bob, and closing his eyes he turned over and
prepared to snatch an extra forty winks. But Frank shook him again.

"Come on," said he. "Stir your stumps. We can slip out before anybody
else awakes, grab something to eat in the pantry, and go down to the
shed and tinker on the plane. Come on, Bob, we can get in a couple of
hours work before going to church."

Bob was wide awake by now, and pleased at the prospect held out by his
chum. Tumbling out of bed, he headed for the shower in the bathroom
which the boys used in common, but Frank restrained him.

"Make too much noise," said Frank. "Anyhow, we can take a plunge down
at the beach before going to the shed. Come on, get into some old
duds and let's hurry."

The boys were dressed in short order. In the pantry, to which they
tiptoed, they found cold tongue and ham, bread and butter, with which
they hurriedly made several sandwiches apiece. It was not much of a
breakfast, but their appetites were those of youth and they enjoyed
it. Letting themselves out of the back door of the sleeping house,
they started on a trot for the little private beach, a good half mile
away. The last few yards were made with the boys shedding garments as
they ran. Then with a shout they plunged naked into the rollers coming
in from the open Atlantic.

It was great sport. For twenty minutes they crashed through breakers,
wrestled, ducked each other, shrieked aloud secure in the knowledge
there was nobody within hearing distance, and in general had a
glorious time of it. At the end of that period they rubbed down
briskly with rough towels until their bodies were in a healthy glow,
then dressed and set out for the airplane shed.

This was located some distance back from the beach where a long, level
stretch of sandy soil, unbroken by tree or bush, made an ideal landing
field. The "shed," as the boys termed it, was, in reality, a
substantial structure of corrugated iron, well-anchored to resist the
severe Atlantic coastal storms. It stood to one side of the route
followed by the boys in going from the house to the beach, with the
rear to them, and was midway between the two points and concealed from
the house by a clump of trees.

When the matter of buying a plane was up for discussion more than a
year before, after the boys and Jack Hampton, their absent chum, as
well as Mr. Temple--himself an enthusiast about flying--all had become
licensed pilots by taking a course at the Mineola flying fields, the
question had been whether to buy a hydroplane.

That question finally had been solved by the purchase of a light,
all-metal plane capable of carrying two passengers besides the pilot
and able to alight on water and land. It was not a stock model but was
built after a special design. All three boys had flown it, as well as
Mr. Temple, and none had ever had an accident. Equipped with a
radiophone head set, to which had been added recently a detector
designed by Bob and Frank to increase the receiving radius, this plane
was the boys' especial pride.

What was their dismay, therefore, when they rounded the shed from the
rear and found the great doors which they had left padlocked several
days before standing open and the interior empty. For several moments
they stood as if rooted to the ground, staring in stupefaction. Then
Bob groaned, and Frank echoed him.

"Gone."

"Gone."

Frank was the first to recover from his dismay and ran forward to look
at the broken padlock, dangling from one leaf of the great folding
doors. "Cut through with a file," he called excitedly to his chum.
"And this set of big bar locks above and below the padlock were cut
the same way."

"I always said we should have had one of those rolling iron screens,
fitting solidly into the ends of the side walls and rolling up into
the roof," groaned Bob, passing on into the interior. "But what's the
use locking the barn after the horse is stolen." Disconsolately he
moved around the interior of the shed, as if expecting to find
concealed somewhere the airplane which he could not yet bring himself
to believe had been stolen.

Suddenly he let out a whoop. "Frank, look at this."

"Great Scott, an Iron Cross," cried Frank, seizing the object held
out. A German Iron Cross it was. "And here you can see how this ribbon
frayed through and parted from the clasp," added Frank.

"Turn it over," said Bob. "If it's a real one given by the Kaiser it
will have the recipient's name on it."

Sure enough, there it was:

"Ober-Lieutenant Frederik von Arnheim."

And beneath was inscribed:

"Pour le merite."

"Great Scott, Bob," said Frank. "What do you make of this?"

"Some Hun officer stole our airplane," said Bob. "That's what I make
of it."

"But the war is over," protested Frank.

"Maybe it is," said Bob darkly. "But if that bird doesn't fly back
with our airplane I'll make war on Germany myself."

Despite his gloom, Frank grinned. He slapped big Bob on the back.
"Come on, old boy," he said. "No use hanging around here. We may as
well go back to the house and report the latest mystery."

"I wonder," said Bob, as they set out, "whether there is any
connection between the two--between this theft of our airplane and
that stuff yesterday."

It was Mr. Temple who was able to provide an answer to that question.
The boys found him up and dressed when they reached home, and himself
considerably excited over a telephone call from New York City. He,
too, was dismayed when told of the theft of the airplane. But when the
boys showed him the German Iron Cross he hit the desk before him a
resounding blow with his fist. Their conversation took place in the
library.

"That fits right into the puzzle," said he. "Boys, while you were out
of the house I had a long distance telephone call from New York City.
The man who called said he was a chauffeur who had driven two men down
here yesterday, that he thought they were on legitimate business, but
that when Bob tried to stop them he saw they were bad ones, as he put
it. Later, when they made him drive them over to the radiophone
station and he heard Tom rout them with his pistol shots, he said he
drove off as they ran for his car and left them. He inquired in the
village and learned my name, and so called me up to clear himself in
case I intended starting a pursuit.

"And he said," added Mr. Temple, leaning forward and speaking
impressively, "that he was pretty certain one man was a Greaser and
the other a Hun. Those were his own words. Of course, he meant one was
a Mexican and the other a German."

"So when this chauffeur abandoned them they stole our airplane to get
away," cried Frank excitedly.

"Exactly."

"Maybe," said Bob, "I copped every cent they had in pulling that
Mexican's coat off his back, and they were without carfare back to the
city."

"Oh, I suppose the German had money," said his father. "The German
probably was an aviator. And they stole the airplane in order to
escape from here quickly before we could get in pursuit of them. I
imagine they'll land in some deserted spot--plenty of them in the
sandy reaches along the New Jersey coast, for instance--make their way
to a railroad, after abandoning the plane, and go----"

"To the Southwest," said Frank, emphatically, interrupting Mr. Temple.

"What do you mean?" asked Bob.

"Weren't there a bunch of German spies in Mexico, stirring things up
there against us, during the war? Well, I'll bet there are some of the
same breed there now making all this trouble for Mr. Hampton," said
Frank.

"A good idea," said Mr. Temple, approvingly. "Well, boys, there will
be no church for us today. This matter has got to be attended to."




CHAPTER VII

KIDNAPPED


"Not a trace, Bob. I don't know what to make of this."

"Nor I, Frank. A fellow wouldn't believe that right here near New
York, in the most densely populated part of the East, two men could
steal an airplane and escape without a trace."

"Oh, I don't know, Bob. You remember last winter when that aviator
from the upper end of Long Island was last seen flying across the
Sound toward the Connecticut shore and was never seen or heard of
again."

"But, Frank, here forty-eight hours have passed. Here we are, Tuesday
morning. Dad has wired every city, town and hamlet in the East. Not a
sign of the machine, nor of the men."

It was, in truth, Tuesday morning. The morning when, everything going
as planned, they should have been setting out on their flight to the
Hampton camp in New Mexico. Instead, the boys were moodily pecking at
breakfast, the airplane had disappeared, and the trip seemed more and
more remote.

To add to their worries, they had been unable to reopen communication
with their chum, Jack Hampton, by radiophone, since that first and
only time the previous Saturday afternoon. All their efforts to call
him met with no response. The day before, moreover, a telegram had
been sent Mr. Hampton by Bob Temple's father, informing him in code of
recent mysterious occurrences, including the theft of the airplane,
telling him the boys had tried to call Jack by radiophone, but without
response from his powerful New Mexico station, and asking whether all
was well with him. No answer had yet been received.

"Mister Robert," said Mary, the maid, entering the breakfast room, as
the two boys sat in moody silence, "your father wants you and Mister
Frank in the library."

The boys hurried to the library at once, where they found Mr. Temple,
very grave of face, bent above a lengthy telegram which he had just
finished decoding.

"It's from Jack," he said, "And the poor fellow is in a lot of
trouble. Listen."

He read:

"Dear Friends, Father has been kidnapped. Two men in airplane carried
him away into Old Mexico. Since getting your telegram few minutes ago
realize it may have been your airplane. Wasn't there and didn't see
it but description of machine given by cowboy on the range who saw it
all tallies with description of your machine."

Mr. Temple paused for breath, and Frank, who had been computing
mentally, interrupted.

"Our plane could do it all right," he said. "That is, if--When did
this happen?"

"Monday noon or a little later," said Mr. Temple.

"Well, they stole it sometime Saturday night," said Frank. "Yes, they
wouldn't have had to make more than eighty miles an hour steady flying
to do it. But where did they get the petrol?"

"Why," Bob reminded him, "we had her stocked with oil and gas. And the
spare tanks filled, too. That wasn't impossible."

Mr. Temple resumed:

"Haven't answered your radiophone calls because didn't get them. Have
been so busy running around in circles, haven't had time to watch the
telephone. But if you call me when you get this shall be on the watch.
Father was kidnapped Monday noon. No word from him. Need your help."

"He certainly does," said Mr. Temple, emphatically, as he concluded
reading. "And he'll get it, too. Come on, boys, let's call him up."

Evidently Jack was on the watch for their signal, for he answered at
once, and as soon as each had tuned to their private 1,800-metre wave
length, the Temples and Frank were given the full details as to the
kidnapping of Mr. Hampton.

He had been riding horseback across the range, miles from any oil
derricks or pumping stations, on his way to visit one of the
"independent" oil operators.

A lonesome cowboy hunting a stray was the only other human being in
sight, and he was a half mile away. Suddenly out of the sky swooped an
all-metal airplane, glistening in the sun. It made a beautiful landing
on the sandy soil, bumped along over a few clumps of mesquite, and
came to rest close beside Mr. Hampton. The latter jumped from his
horse, and started running toward it. Evidently, Jack thought, his
father believed the Temples and Frank had unexpectedly arrived.

Then the watching cowboy saw two men leap from the airplane and start
for Mr. Hampton, who turned as if to run. Thereupon, one of the two
pointed a revolver at him and he turned, perforce, and surrendered. He
was put into the airplane, the two men again climbed aboard, and the
machine soared up into the sky before the astonished cowboy could more
than set his horse in motion.

All this Jack explained and then asked:

"Mr. Temple, what would you advise me to do?"

"Does anybody else know of this?"

"Only the cowboy who saw it and I," said Jack. "This cowboy knew
father by sight, and came direct to me with the information. I've
made him promise not to tell anybody until he hears from me."

"That's right, Jack," said Mr. Temple, very earnestly. "This
information must not get out. I believe, Jack, your father will be
safe from harm and that the men who seized him are intent on
embroiling Mexico and the United States. Now we don't want any more
wars, Jack, and we must try to get your father back without the aid of
troops."

"Yes, sir," said Jack. "Father and I have suspected what the game was,
and that was why I told the cowboy to say nothing."

"Good," said Mr. Temple, approvingly. "Now, Jack, that the mystery of
the airplane's disappearance has been cleared up, we are ready to
leave at once. We can get out of New York City on the 6 o'clock train
tonight. Look for us Friday. I'll say good-bye until then, and let the
boys speak to you, for I know they are dying to do so."

While the boys and Jack conversed, Mr. Temple sought out his wife.
After explaining the necessity for his abrupt departure with the boys
for New Mexico, he said:

"I should worry if I thought you would be subjected to annoyances
while we were away. But I believe there will be no more trouble here.
And with the servants in the house and the guests you have invited,
you may feel perfectly safe."

"Oh, Dad, I think you're awfully mean not to take me along," pouted
Della, who was present.

"Why, Lassie," said her father, "with a bunch of harum scarum boys to
look after, my hands will be full enough."

"Yes, you think they're just boys," flashed his young daughter. "But
you wait and see. They'll be taking care of you. Just you wait and
see. Frank is awfully clever."

"Frank?" said Mr. Temple teasingly, with a meaning look.

Della flushed, and made an excuse to leave the room a moment later.

"I wish, George, that you wouldn't tease her about Frank," said Mrs.
Temple. "She's such a child."

"Yes," said Mr. Temple, thoughtfully. "I suppose so. But," he added,
"I'm glad she likes Frank."




CHAPTER VIII

HELD FOR RANSOM


"Great Scott, Jack, how different you look. What a peach of a get-up."

The Temples, father and son, and Frank Merrick stood on the gravel-bed
outside the little wooden box doing duty as station at Ransome, New
Mexico. The transcontinental flier which had dropped them, was
dwindling in the distance. Jack Hampton, whom the chums and Mr. Temple
had crossed the country from New York to join, was in the center of
the group. Greetings had been exchanged, they had all slapped each
other on the back indiscriminately and enthusiastically, and now Bob
Temple stood off at arm's length to admire his chum.

"Yes, sir. Some get-up," he added.

"Righto," agreed Frank, also gazing at the handsome Jack admiringly.
"Where do you get 'em? Lead me to the store right away."

Jack, who was 19 and the oldest of the three chums, was almost as tall
as the six-foot Bob, but of more slender build than that gridiron
warrior. He had the build of a thoroughbred, long legs, flat hips,
trim waist, deep chest and broad shoulders and a flat back. Both at
dashes and distance running Jack easily was supreme at Harrington Hall
Military Academy, which all three boys attended. Like Bob he was fair
and had curling chestnut hair. His eyes were blue and lively, his
features not too regular. Altogether, he was a striking figure.

Today he was dressed in khaki shirt and breeches. Instead of puttees
he wore high, laced leather boots that reached to his knees. On his
head, pushed back so that his wavy hair showed in front, was a
wide-brimmed sombrero. By his side, suspended from a cartridge belt,
swung an automatic revolver in its holster. This was the outfit so
admired by his chums from the East, trim in their light-weight summer
suits of the latest cut and wearing low tan shoes more adapted for
city streets than for the sands stretching inimitably on every hand.

"We've worried considerably while aboard the train, Jack," said Mr.
Temple, "for fear something dire might happen to you these last two or
three days. I'm glad to see you are all right. Any word from your
father?"

Jack shook his head in negation. "Not a word," said he, "since those
two rascals picked him up in your airplane and headed for Old Mexico."

"Well, don't worry, Jack," said Mr. Temple. "I don't believe his life
is in danger."

"I'm trying not to worry, sir," said Jack. "But now that you and the
fellows are here, we shall have to get busy at once. It has been
pretty hard to wait for you. I wanted to ride into Old Mexico myself
at once."

Bags in hand the group was moving to the rear of the station, and now
came in sight of a ramshackle automobile with a Mexican at the wheel,
easily distinguished by his swarthy coloring and his ragged mustaches,
as well as by his peculiar dress--a steep crowned hat like a sugar
loaf, with a very wide brim, a tight bolero jacket that did not reach
to the waist and disclosed a dark blue silken shirt beneath and
tight-fitting trousers that flared at the bottom.

"That is Remedios and his flivver," explained Jack. "He does odd jobs
all through this region. I hired him to take us out to camp. But
before we climb aboard, take a look at this view."

Obediently, they paused and gazed at the surrounding country. In the
foreground was a wide dirt street at the rear of the station. For the
equivalent of the length of a city block it was lined on both sides
with wooden structures one-story in height, but with the false fronts
of the frontier country pretending to second stories--a front wall
sticking above the roof and with the semblance of windows painted on
it. A dry goods store, a Chinese laundry, an alleged hotel, several
restaurants, several ex-saloons still carrying on some kind of
business--these comprised the lot. At one end the street ran abruptly
into the desert. At the other was a cluster of old freight cars made
into dwellings, with Mexican men, women and children loitering in
front in the sun. This was Ransome.

"Not much of a town," said Jack, "just a trading post for a wide
stretch of this country around here. But look at the setting, will
you?" And he swept a hand in a wide gesture indicating the horizon.

On every hand stretched the desert, broken by clumps of mesquite and
cactus with the only trees in the landscape the thick belt of
cottonwoods lining the banks of a stream that rose in the mountains to
the north and ran by the town. North, east, south and west lofty
mountains gleamed on the far horizon, while closer at hand rose the
foothills. These latter were of fantastic shapes, like castles, tables
or crouching animals, and of the most vivid coloring. Over all was the
warm and brilliant sunshine of late afternoon. As for the air, it was
clean and despite the warmth of the day already beginning to turn cool
as the sun hovered on the rim of the farthest mountains to the west.

"Some country," said Bob emphatically.

"Wait until you have known it day in and day out for months," said
Jack. "You will never want to go back to Long Island."

"Is that the way you feel about it, Jack?" asked Frank.

"Oh, well, I suppose I'll want to go home sometime," said Jack. "But
just the same, I'm in love with this country. As for the old-timers
off there in the hills, you couldn't drive them away."

"Say, Jack," said Frank, as they all continued standing and gazing at
the surrounding scene, "I thought we'd see some oil derricks around
here. But there isn't one in sight."

"No, Frank," interposed Mr. Temple, in explanation, "you see the
Independents are mainly located over in the Panhandle, or upper
western portion of Texas and in Oklahoma. That is east from here. But
Mr. Hampton had his geologists in through this region, and they
reported the prospects for finding oil favorable. Then the
Independents came in quietly and took up leases, and Mr. Hampton
followed to prepare for development of the field."

"Yes, that's the way of it," agreed Jack.

"Say, Jack," said Frank, "I'm hungry as a hunter. If we are going to
get dinner at your camp, let's move along. How far is it, by the way?"

"Ten miles," said Jack, leading the way toward the automobile with its
dozing Mexican at the wheel. "Come on."

The others followed and were about to climb into the automobile when
the rapid hoofbeats of a galloping horse ringing on the sun-baked clay
of the street drew their attention, and they paused.

"Why, it's Gabby Pete," said Jack in surprise, moving forward a step
as the rider reined up his horse so sharply that it reared and slid on
braced hind legs. The animal came to rest so close to him that Jack
was forced to give back a step, and it stood there snorting and
blowing.

An oldish man of tremendous girth, but who sat his horse easily
despite his size, grinned down at Jack. He was white-haired and under
the brim of his sombrero little eyes twinkled genially and shrewdly in
a round, fat face.

"What brings you here, Pete?" asked Jack, sharply. "I thought you were
at camp, getting dinner for my guests." He indicated the boys and Mr.
Temple, who stood close at hand, looking on. "Who will prepare dinner
for them now?"

Gabby Pete, the talkative camp cook, scratched his head under his
sombrero, and looked solemn. "Waal, they'll have ter wait a bit," he
said. "But I kin rustle grub in a hurry onct I git back ter camp. An',
anyhow, Mr. Jack, a feller came to camp a while ago in one o' them
there aeryoplanes. Jest flew up almost to the door an' steps out an'
gin me this yere letter." Here Gabby Pete produced a missive from the
front of his shirt, and passed it to Jack. "He sez as how it war most
partickler that you git it right away. So I rid in with it," said
Gabby Pete, adding aggrievedly: "an' now you hop on me fur it."

Jack seized the missive in a sudden fever of anxiety. An airplane? He
opened the letter, took in its contents at a glance, and turned
excitedly to his chums.

"Father's held for ransom," he cried. "Here. Read this."




CHAPTER IX

ON THE DESERT TRAIL


Eagerly Mr. Temple, Bob and Frank gathered around Jack, crowding to
read over his shoulders the missive left at camp by a messenger in an
airplane and brought to Ransome by Gabby Pete, the camp cook,
following Jack, who had gone to the little New Mexican town to meet
the party from the East.

The writing was cramped and foreign, as if the pen were wielded by a
hand more accustomed to form German script than English letters. The
missive was brief:

"Sir, this is to inform you that Mr. John Hampton is held in a secure
place. One hundred thousand dollars must be paid for his release. A
man riding alone must bring the money in United States bills of one
thousand dollars each to the Calomares ranch two weeks from today. He
must wear a white handkerchief in his hat."

While the others read, Jack turned to Gabby Pete and said
authoritatively:

"Pete, you heard me say something just now about my father being held
for ransom. I believe you are my friend." Gabby Pete nodded
violently. "Well, forget what you heard. If anybody asks you, remember
that father has gone East on business."

"Sure, boy," said Pete. "I'm a tombstone. Well, me an' Angel Face
here," and he slapped his horse affectionately, whereat Angel Face
reared and pranced, giving the lie to her name, "we may as well git
started fur camp so's to feed you when you arriv."

Jack laid a restraining hand on Pete's knee. "Wait just a minute,
Pete. Do you know where the Calomares ranch is located?"

Pete nodded. "Aw, sure," he said, "that must be Don Fernandez y
Calomares, down in Ol' Mexico. That's a good hundred mile acrost the
border. It's in a valley in them mountains," he added, pointing to the
darkening southern horizon.

"And who is this Don?"

"Waal," drawled Gabby Pete, plaintively, "I stick to hum so much o'
the time I never git to talk to nobody nor hear the noos. But seems to
me I did hear onct about him. Yes, sir, somebody sez as how Don
Fernandez lives in a palace in that wilderness jest like a king of
old, with armed ree-strainers or whatever you calls 'em----"

"Retainers, Pete," said Jack, suppressing a smile.

"Yes, that's the word. An' this feller what tol' me sez as how he's
very proud and haughty-like an' has a beyootiful daughter,
an'----an'----"

Pete dropped his voice, and paused, eyeing Remedios, the Mexican in
the nearby flivver.

"Think he kin hear me," he whispered.

"Guess not," said Jack. "Why?" He, too, looked toward Remedios. The
latter had his back to them and was blowing indolent wreaths of smoke
from a brown paper cigarette.

"I don't trust that feller, that's all," whispered Gabby Pete
hoarsely. "He's down acrost the border too much o' the time. Anyhow,
as I was sayin', this yere Don Fernandez is agin the Obregon gov'ment
an' backin' a new revolution. That's what the feller tol' me, anyhow.
Waal, Mr. Jack, Angel Face an' me will go an' git dinner." And with a
slap on his horse's flank that caused her to spin about and dash away,
Gabby Pete was off.

Jack turned to his companions.

"First thing is to get to camp, I guess," he said. "Then after dinner
we can talk over what has to be done. What do you say?"

"I say let's eat," said Frank, plaintively.

"He's got the biggest appetite for his size I ever saw," said Bob,
affectionately, slapping his smaller chum on the back.

"I second Jack's motion," said Mr. Temple, seizing his bags and
leading the way to the car. The others also picked up their bags and
followed. "We know now that your father is safe, Jack," said Mr.
Temple. "So the news in that note wasn't so bad, after all."

"That's right," agreed Jack. "Well, climb in fellows, and let's get
started."

It was a tight squeeze. Jack sat in front with Remedios and one of the
bags. Mr. Temple and Bob, both big individuals, filled the rear with
the balance of the bags. Frank, who had gone to the front of the car
to crank it, found no room within for him when he returned. He leaped
to the running board.

"I'm light," he said. "I'll sit on the door. Let's go."

Remedios opened the throttle and with a rattle and roar, the
ramshackle old car darted ahead on the road taken by Gabby Pete, and
soon had left the town behind and was out on the desert.

Only the upper edge of the sun stood now above the western mountains,
and the purple shadows were long across the plain. In the east the sky
was darkest blue and the stars already twinkled brightly. A rosy light
lingered at the zenith, while above the western mountains the sky was
ruddy bright with the afterglow as the sun slipped farther and farther
down and finally vanished altogether. Then night began to descend with
a swiftness unknown in the East. The rattle of the car made
conversation difficult and the newcomers lapsed into silence,
becoming absorbed in watching the majesty of the scene.

Presently the engine began to miss fire, then emitted a final groan as
Remedios closed the throttle, cutting off the flow of gas, and
stopped. Remedios threw the clutch into neutral, applied the brake,
and climbed out. Raising the cover of the hood, he peered within. Then
he shook his head dolorously.

"It is of no use, Senor," he said to Frank, who had jumped from the
running board and stood beside him. "She is finish. The spark plug,
she is on the--what you call it?--the bum." And with an air of
finality, he closed the cover. At the same moment he turned to peer
anxiously down the road ahead, whence came now on the still twilight
the thudding hoofbeats of a galloping horse, rapidly growing louder.

His mechanical instincts awake, however, Frank paid no attention to
the approaching horseman. He had again lifted the cover, as Remedios
turned away, and, lighted match in one hand, was twisting at a spark
plug with the other.

"Shucks," he cried, withdrawing his head, "that Number One plug wasn't
screwed in tightly enough, that's all. I'll bet she'll go now, just
the way I tightened her by hand. And if I only had a pair of
pliers----"

At that moment, the galloping horseman dashed up alongside, pulling
his horse back on his haunches. It was Gabby Pete, his hat gone, his
face red with excitement. Far over he leaned to call to the astonished
occupants of the car.

"Bandits," he cried hoarsely. "Greasers. Comin' in an auto. I come
back to warn you." And facing about he pointed to where a cloud of
dust behind him on the desert road indicated a rapidly oncoming car.

"Grab that crank," cried Frank to Remedios, and he sprang for the
driving wheel. "I'll make this old bus go."

"Not so fast, Senor," said Remedios suavely, and seizing Frank's arm
he whirled the young fellow about.

Frank looked into the muzzle of a revolver which Remedios held leveled
at him.




CHAPTER X

A BRUSH WITH THE ENEMY


"Crack."

The explosion of a revolver shot.

"Wow."

A yell of pain.

Remedios seized his shooting wrist in his left hand and danced up and
down in the road, while his weapon fell to the ground.

Frank, who a moment before had been gazing into the leveled weapon of
the traitorous Mexican chauffeur, whirled about to face his friends in
the car.

Smoking revolver in hand, Jack Hampton stood upright in the front
seat. It was he who had fired the shot.

"I didn't touch him," cried Jack, "merely shot his revolver from his
hand. Jump in Frank, for here come the bandits."

With a rattle and roar the car of the bandits approached, not the
length of two city blocks away on the desert trail.

Frank took in the situation at a glance.

"Crank for your life," he ordered Remedios. "Jack, keep him covered."

As the Mexican sprang to the crank, and started turning, Frank leaped
to the driver's seat of the flivver and manipulated throttle and
spark. With a clatter the engine turned over and began to race.

Closer came the bandits, their car slowing down as it approached.

Jack leaned far over the windshield, his weapon leveled at Remedios.

"Up on the hood," he shrieked. "Up with you, or I'll shoot you full of
holes."

Remedios threw himself sprawlingly over the hood.

The bandits' car had slowed almost to a stop, four or five lengths
away. Frank released the hand brake, pressed the clutch into low with
his foot, and shot ahead.

Shifting the clutch into high, Frank opened the throttle wide and the
old rattletrap seemed fairly to leap ahead, its wheels spurning the
ground. The lights of the other car which had theretofore seemed
dimmed were switched to full brightness. Before the blinding glare in
his eyes, Frank involuntarily ducked his head.

As his eyes left the road, the car swerved. A shot rang out from the
car of the bandits, ripping high and doing no damage.

"Look out, Frank. Swing her over," cried Jack in alarm.

Shouts of panic rose from the car of the bandits, too.

Too late.

There was a crash, the flivver lurched, then sped on. As rapidly as
possible Frank brought it to a stop and then stood up to look back and
view the damage.

Mr. Temple and Bob, in the rear seat, already were on their feet. Jack
stood beside Frank, peering into the shadows behind. The moon was in
its first quarter, low down and shed only a faint radiance. But even
by the wan light, it could be seen that something dire had happened to
the car of the bandits. It stood sideways across the road, leaning
drunkenly to one side. And to the ears of the boys came groans from a
number of dark figures in the road.

Gabby Pete, temporarily forgotten by the boys in the excitement,
galloped up, cheerful voiced.

"As neat a trick as ever I see," he cried approvingly to Frank. "You
tuk off their hind wheel jest like a knife cuttin' butter. They're
tumblin' around in the road, a half dozen of 'em. Hey, look out." And
Gabby Pete bent low on his horse as a bullet whistled overhead.
Another and another followed, and there were shouts of vengeance, and
imprecations.

"They're a-comin' to," cried Gabby Pete, slapping Angel Face on the
flank, so that the horse leaped forward with a snort. "I'm on my way."
And he disappeared into the darkness.

"We're on our way, too," cried Frank, opening the throttle and
pressing down the clutch, as more bullets whistled overhead. "Give 'em
a shot, Jack, and everybody stoop down."

Jack fired off his revolver, shooting high purposely. He wanted merely
to frighten their pursuers into desisting. Then the car gathered
momentum, and was soon out of range. Presently Frank, who had been
driving the flivver as fast as it would go, with the result that they
were all tossed about while the car lurched precariously over the
rutted road, slowed down to a more moderate pace.

"Anybody hurt?" he called. "They never touched me."

"Not a scratch," answered Mr. Temple.

"Same here," cried Bob and Jack together.

"Say, though," cried Frank, suddenly realizing Remedios no longer
sprawled on the hood, "we've lost our passenger."

"Good riddance," said Bob.

"Must've thrown him off when we struck the other car," decided Jack.

"Or else he jumped off when his chance came," surmised Mr. Temple.

To a query from Frank as to the route to be followed and the distance
to camp, Jack made answer that the road lay straight ahead with no
laterals cutting into it, and that camp was only a couple of miles
beyond.

"Say, Jack," declared Bob with a laugh, "that was some reception
committee you got out to meet us."

"Yes," kidded Frank, "what were you aiming to do, anyway? Put on a
Wild West thriller for a bunch of tenderfeet fresh from New York?"

Jack laughed. "Tenderfeet, your grandmother," he said. "It looked to
me as if the effete Easterners put on the thriller for the bandits."

Relieved at the safe outcome of their adventure, everybody joined in
the laugh, and for several minutes the high good humor manifested
itself in jokes bandied back and forth. Then a 'dobe ranch house
loomed ahead, low-lying, of four or five rooms, a wide, dirt-floored
porch along its length, upon which the rooms gave through separate
doors. At the rear were a clump of shadowy outbuildings and a corral.
To one side and some distance away stood a low frame building and a
high, latticed tower with antennae, which the chums recognized with a
shout of delight.

"There's the radiophone station, hey, Jack?"

Frank drew the car to the porch, and Gabby Pete, at the sound of its
approach, opened the door of the kitchen and emerged, big spoon in
hand, the lamplight streaming from the room behind him, and savory
odors floating out to the hungry boys.

"Come an' git it," he called sonorously.

"What does he mean Jack?" asked Bob.

"I hope he means dinner," said Frank, sniffing hungrily.

"He does," laughed Jack. "That's the way camp cooks announce food is
ready in the cow camps, as I understand it. And Gabby Pete is an old
cowman."

"Well, lead me to it," said Frank, and all followed Jack into the
house.




CHAPTER XI

JACK CANNOT SLEEP


"Well, now, boys, let's see where we stand," said Mr. Temple, after
all had partaken heartily, amid excited but disjointed conversation,
of a surprisingly good dinner of pork and beans, boiled potatoes,
fresh tomatoes and lettuce, bread pudding and coffee. He pushed back
his chair as he spoke, and lighted a cigar.

"First of all," he said, "we have got to consider the kidnapping of
Mr. Hampton and decide what shall be done in the matter, what moves we
must make. Then there is this series of mysterious happenings, all of
which have a bearing on the case, if we can find the solution.

"Here, for instance, is this man Remedios. Evidently he was in league
with the Mexican bandits who attacked us, and it was his part of the
conspiracy to stage a breakdown so that we could be easily attacked.
Now who were the bandits, and what did they want? Were they ordinary
robbers after money, or was their object something deeper? Was it
part of this plot against our oil interests?"

He paused to puff his cigar into renewed life. All three chums had
been listening with eager attention. Now Jack Hampton spoke. Mr.
Temple earlier had elaborated for Jack's benefit his theory that a
faction of Mexican rebels was responsible for the outrages of which
they had been the victims, hoping thereby to embroil Mexico and the
United States and thus cause trouble for President Obregon.

"Mr. Temple," said Jack, leaning forward, "I do not believe those
bandits were after money. Didn't it strike you all as strange that
they were in an auto? Well, it did me. The bandits of the border
usually are mounted on horseback. These men, on the contrary, had a
high-powered car. No, that attack was due to a carefully laid plan.
And do you know what I think their purpose was? It was to capture
you."

Bob and Frank, elbows planted on the table, leaned forward surprised.
Mr. Temple, however, showed no surprise, but merely looked thoughtful.

"You see," continued Jack, "you are an American of wealth and
position. They already have captured father. Now, if they were to
capture you, there certainly would be some commotion at Washington,
the national capital, that would make trouble for President Obregon of
Mexico. Maybe another punitive expedition would be sent into Mexico,
like General Pershing led in the time of Carranza, after Villa's raid
on Columbus, New Mexico. At least, that's what they expect, I guess."

Mr. Temple nodded, but remained silent.

"But, Jack," demanded Frank, "if you are right in your surmise, then
it means that these fellows knew in advance of our coming."

"Yes," said Jack, "that's the puzzling thing about it."

"Anybody here know we were coming?" asked Bob, speaking for the first
time.

"Sure," said Jack, "Gabby Pete knew. And Rollins, father's assistant.
But you met the one, and you know he can be trusted. As for Rollins, I
don't know much about him. He's a queer, silent man. Not here tonight,
because he left early this morning to see a man on business over here
some twenty miles or so. He said he might not return tonight. But I
know father trusted him."

"Then, Jack, there is one other thing to be considered," said Bob.
"And that is, has anybody among our enemies--for I suppose we can call
them that--listened-in when we spoke by radio?"

"Of course," said Jack, "with all these amateur receiving sets in use
nowadays it is pretty hard to get absolute secrecy. But, in the first
place, since that Washington conference, the government has limited
the use of certain wave lengths. Now we are licensed to use an 1,800
metre wave length, and I imagine there are very few--at least in this
region--who could 'tap' our conversation. In addition, of course, we
used our code in discussing when you would arrive."

"No, you're wrong," said Bob. "You used the code when you telegraphed
that your father was kidnapped. But, as I recall it, when we spoke by
radio after getting your wire, we all were so excited we never thought
of the code."

Frank nodded agreement. "That's right," he said. "But, anyhow, we
never thought of making it a secret. Perhaps your cook--this Gabby
Pete--said something innocently in town. Or the word got around
somehow."

"Yes, I suppose that's the way it happened," said Jack, dismissing the
subject. "But the question now is, what are we going to do? Shall we,
telephone the county sheriff about this attack on us tonight and about
Remedios? And--what shall we do about father?"

Mr. Temple who had been puffing thoughtfully throughout this
discussion, his head bowed, now looked up, and shook his head in
negation.

"Let's not notify the sheriff," he said. "The minute we bring the
authorities into this, we run the danger of letting our whole story
become known. Then the end which these mysterious enemies of ours
seek will be attained. That is, the government will be drawn into the
situation.

"As to your father, Jack," and Mr. Temple paused, "well, we shall have
to think the matter over pretty carefully before we undertake to do
anything. In the first place, as I have said before, I believe he was
captured in order to make trouble between Mexico and the United
States. Now, here comes a note from his captors demanding that we pay
a ransom of one hundred thousand dollars. How does that fit into my
theory?

"Well, if we appeal to Washington and ask our government to demand Mr.
Hampton's release, there certainly will be trouble. And that, I
believe, is what the enemy counts on us to do. If they really were
after a ransom, and had no other object in view, it is likely they
would not have asked for so big a sum, and also would not have given
us two whole weeks in which to carry out their demands. No, I am
convinced they expect us to go to Washington and make trouble.
Therefore, that is the one thing we must try to avoid doing."

"But, look here, Mr. Temple," said Jack, impulsively and with just the
slightest quiver in his voice, "he's my father."

"Yes, I know, Jack," Mr. Temple said in a sympathetic tone, "and I
know what you're thinking of. You're thinking your father is a
prisoner and ill-treated. And you're saying to yourself that while we
hold back here from appealing to the government, something dreadful
may happen to him. Isn't that so?"

Jack gulped unashamedly, and turned his head away. "Something like
that," he said, in a muffled voice.

The older man dropped a hand on his shoulder. "Don't worry too much,
my boy," he said. "We may appeal to Washington, and let the
consequences go hang, if that is the only way to bring back your
father. But we don't want to act too hastily. Let's turn in now and
get a good night's sleep. Then in the morning we'll decide on
something definite."

It had been a long discussion, and Bob and Frank were content to do as
Mr. Temple proposed. Jack, perforce, agreed, although the strain of
the last few days, which he had carried alone, was beginning to tell
on him and he yearned for instant action. He showed the others to
their rooms, Bob and Mr. Temple sharing Mr. Hampton's room, and Frank
bunking in with Jack himself.

After Frank had undressed and tumbled into bed, so dog-tired, as he
said, that he could barely keep his eyes open to see the way to his
pillow, Jack went out to stand in the starlight on the porch. After
leaning against a pillar some minutes, during which his active brain
kept milling endlessly over the details of the past few days, he had
an impulse to go over to the radiophone station and talk to the guard,
an ex-cowboy, on duty there since the attack by three Mexicans at the
time this story opened.

Hands in his pockets, head bowed in thought, he moved across the hard
packed sand, his feet making practically no sound.




CHAPTER XII

JACK DISCOVERS A TRAITOR


Two figures stood at the door of the radio station power house. The
station was a duplicate of Mr. Hampton's other station on his Long
Island estate, earlier described. So engrossed were the two men in
whispered conversation that they were unaware of Jack's noiseless
approach.

The soft sibilant sound of whispering which came to his ears just as
he was about to approach the door roused Jack from his reflections.
His suspicions were on the alert because of the happenings of recent
days, and he halted. Certain, after standing a moment with every nerve
tensed, that he had not been seen, Jack backed cautiously until again
around the corner of the building.

Who were the two men? What were they whispering about? Pressing
against the side of the building, Jack thought quickly. One of the two
must be the night watchman. Perhaps the other was the man who kept
guard at the station by day. If he were, thought Jack, then, perhaps,
some new danger menaced and the night man had called the day man to
help him. This theory also would account for the fact that they were
whispering, instead of conversing in normal tones.

So probable did this supposition seem to Jack that he decided to join
the men and ask what the danger was. Caution, however, prompted him to
reconnoitre by peeping around the corner before stepping into the
open. The next moment he was thankful he had done so. For, as he
looked, one of the two struck a match and held it in cupped hands to a
cigarette, and Jack saw the man was Remedios.

Drawing his head back quickly, Jack leaned against the building,
trying to compose his thoughts. What was Remedios doing here? Not many
hours before he had foiled the plan of the traitorous Mexican
chauffeur to deliver him and his friends to the enemy. Was Tom, the
ex-cowboy, on guard at the radio plant, a traitor? Jack could not
believe it.

Footsteps were approaching from around the corner. Jack looked around
wildly. There was no shelter near enough to which to flee. He whipped
out his automatic, flung himself down alongside the wall, and waited.

Two men appeared, but instead of rounding the corner they moved
straight ahead. They were in earnest, but low-voiced conversation.
They did not see him.

Jack stifled an exclamation. The man with Remedios was Rollins, his
father's trusted assistant. So stunned was Jack at the revelation that
he did not strain to overhear what they were saying. In a moment they
were beyond earshot.

Trembling with rage at this evidence of treachery on the part of
Rollins, Jack rose to his feet. He intended to stalk the two
conspirators. Then a new idea occurred to him. What were they doing at
the radio plant? Perhaps, for reasons of their own, they had damaged
it or put it out of commission. He decided to investigate.

Rollins and Remedios were now out of sight toward the front of the
ranch house. Perhaps Rollins would have the audacity to take the other
into his room, which opened like the other rooms directly upon the
porch or gallery. If so, Jack could surprise them later. First, he
would investigate at the radio plant.

Walking swiftly, he approached the door of the power house. An
electric light shone within. The guard, Tom, jumped up from a chair
where he had been sitting, reading, at the sound of Jack's hurried
footsteps. His hand reached for the ready revolver at his side, but
was withdrawn at sight of his visitor.

"Oh, it's you, Jack," he said, addressing him familiarly, for a warm
friendship had sprung up between the two. "I thought it might be a
Greaser."

"Tom," said Jack, without any preliminaries, and showing his
excitement in his voice and manner, "what was Mr. Rollins doing here?
Who was that with him?"

Well enough Jack knew who the stranger was. But good friend though Tom
was, Jack wanted to test him. The circumstances certainly were
suspicious.

"Didn't see the other feller," Tom answered. "He stayed outside. Mr.
Rollins said he was an oil driller. Mr. Rollins went into the station
there." Tom motioned to the radio operating room beyond a closed door.
"Asked me to throw on the juice so he could use the telephone."

"Whom did he talk to?"

"Why, I don't know," said Tom. "How would I?"

"How long was he in there?"

"Why, fifteen, twenty minutes. Maybe half an hour. Why, Jack? Anything
wrong?"

"Yes, Tom, there is," said Jack. "Can I trust you?"

Tom looked hurt.

"That's fer you to say."

"Excuse me, Tom," said Jack. "But after what I've just seen I don't
know whom to trust. Yes, I believe you're true blue, Tom. I'll tell
you. But wait a minute."

He walked to the door and looked out. The coast was clear.

"Tom," said he, returning, "I'm going to take you into my confidence.
Listen."

In as few words as possible he related their adventures that day and
the part played by Remedios. Then he added that in Mr. Rollins's
companion he had recognized the Mexican chauffeur.

"What do you make of it?" he asked.

"Treachery," said Tom, emphatically. "But who'da thought it of Mr.
Rollins?"

They looked at each other puzzled.

"I wish I knew whom he spoke to by radio and what he said," declared
Jack.

"Wish I'da listened," mourned Tom.

Both stood silent. Suddenly the still night was shattered by a series
of racketing explosions. Jack sprang for the door.

"Remedios's flivver," he cried to his companion. "There isn't another
car in the world can cough like that."

By the time he had emerged from the radio station the car could be
heard shooting away down the desert trail toward Ransome.

"Too late," said Jack, disgustedly. "He's gone. I should have
surprised them together."

He thought a moment, then turned to the other.

"Listen, Tom," said he. "Not a word about all this. I think I'll not
let Rollins know that I suspect him, but will talk this over first
with my friends. And if he comes here to radio again listen to him,
and report to me what he says."

"All right," said the big ex-cowboy. Then as a new idea occurred to
him, he asked: "But how about tellin' my side pard, Dave? He's on duty
days. He oughta know, too."

"I don't know Dave as well as I do you," said Jack. "Certainly he
ought to be informed, so that he can be on the watch, too. Can he be
trusted?"

"You can count on Dave," said Tom. "We been pardners for years. That
bow-legged son o' Satan an' me been through lots o' ruckuses in our
time. If there's any shootin' to be done, count us in. You know how I
kin shoot."

"I ought to know," said Jack. "You taught me."

"Well, then, I'll let Dave in on the secret."

"All right," said Jack, moving away toward the house. "Good night."

He started for the ranch house, but again came back.

"Rollins mustn't know I was down here," he said.

"He won't know from me," Tom assured him.

When Jack reached the house, he found Mr. Temple, Bob and Jack on the
front porch in their night-clothes. Rollins was there and had
introduced himself. All four were discussing the disappearance of the
flivver.

"You know how I sleep," said Bob. "But it made so much noise it waked
even me."

"Where have you been, Jack?" asked Frank. "Why, you haven't undressed.
I thought you turned in when I did. But I was so sleepy I never
noticed when I tumbled out of bed that you weren't there."

Jack felt Mr. Rollins's eyes on him. It made him uncomfortable.

"Oh, I couldn't sleep," he said. "So I came out for a turn in the
night air before going to bed."

"Where were you walking?" asked Mr. Rollins quickly.

Jack found lying distasteful, but decided it would not do in this case
to tell the whole truth. Fortunately, on leaving the radio station, he
had swung about in a circle, so as to approach the house from an
almost opposite direction.

"Over there," said Jack, indicating the direction from which he had
come. "There's a little rise some distance beyond there, but in this
feeble moon-light you can't see much, so I came back. Then I heard the
flivver."

"Do you think that fellow Remedios came here himself and drove it
off?" asked Frank.

"He certainly had his nerve, if it was he," said Bob.

Jack noticed that while Rollins was watching him keenly Mr. Temple,
who had not taken part in the conversation, was studying Rollins.

"Oh, it must have been Remedios," Jack said boldly. "Did anybody get
close enough to see him? Who came out first? Did you notice, Mr.
Rollins? You must have just arrived. I see you are still dressed."

"Yes, I had put my horse up in the corral," said Rollins, calmly, "and
was walking over here to the house, when I heard the car. I came
around to see who was calling at this late hour, but all I could see
was the disappearing car. Of course, I knew nothing of your day's
adventures until your friends came out, when we introduced ourselves
and explanations followed."




CHAPTER XIII

THE NET IS DRAWN TIGHTER


That obvious lie on Rollins's part gave Jack the final assurance that
the man was in the plot against them. Burning with indignation, he
wanted to expose Rollins but with an effort of self-control he choked
back the hot words and also managed to keep his anger from showing in
his face.

But it was an effort. Fortunately the others came to his rescue. Frank
began to shiver in his pajamas and called attention to the fact that
the night air was chill.

"Yes," said Jack, glad of the change in subject, "no matter how warm
the days out here, the nights are always cool. Let's go inside."

All trooped into the living room, which was dining room, too. In the
big fireplace they found a wood fire laid by the thoughtful Gabby
Pete, ready to be touched off in the morning. The talkative camp cook
slept in the bunkhouse some distance away, in the opposite direction
from the radio plant. While the others dragged blankets from their
beds and returned to the living room, wrapped up in them like
Indians, Jack touched a match to the wood and the fire soon was
blazing merrily.

Rollins would have excused himself on the plea of fatigue after a long
day's ride, but Mr. Temple halted him.

"So long as we are here altogether," he said, "it won't hurt matters,
and may help them, to have a little talk."

From his chair in front of the fire, Mr. Temple looked up inquiringly
at Rollins, who stood to one side of the fireplace, his face in the
shadows. The latter did not speak. Jack thought quickly. Was it wise
for Mr. Temple, unaware of Rollins's duplicity, to discuss matters
with him? He decided not. He was bending down to throw more wood on
the fire and without rising he interposed an objection.

"Mr. Rollins must be pretty tired," he said, glad his face was averted
because he feared the scorn in his eyes would betray him. "And we've
all had a hard day. Suppose we let the discussion go until tomorrow."

Rollins spoke precipitately, and Jack believed there was a little note
of relief in his voice.

"Yes," said he, "that would be better. I am pretty tired, as Jack
says. Well, I'll turn in. Good night. I'll see you at breakfast and
after that we can have our talk."

Shaking hands with Mr. Temple and throwing curt nods to Bob and
Frank, Rollins left the room. A moment later Jack arose and followed
swiftly but silently to the door on the gallery. Peering around the
doorpost cautiously, he assured himself Rollins had entered his own
room, then returned.

The others looked at him in surprise, unable to understand the meaning
of his actions. Jack soon enlightened them.

Crouched before the fire and with his eyes on the door for signs of
interruption, while the others pulled their chairs close about him,
Jack in a low voice outlined his experiences of the night.

When he spoke of Rollins's using the radio, Frank uttered an
exclamation.

"That's how the enemy learned just what time we would arrive," he
declared.

Jack shook his head.

"No," said he. "All Rollins had to do to spread that information was
to tell Remedios. The latter could notify the men who laid for us."

"Well, then, whom was he telephoning to?"

Jack again arose and moved to the door and peered out. No signs of
life. He returned and resuming his position said in a low voice:

"That's what I've been asking myself. I've thought it over and I
believe I've found the answer. Either he was radioing to the Calomares
ranch in Old Mexico where father probably is held a prisoner, or else
he was sending a message to the fellows who stole our airplane."

Bob, the belligerent growled in his throat.

"The big stiff," he muttered. "I'll go get him now and we'll choke it
out of him."

He half rose from his chair, but his father pushed him back.

"Don't blame you, Bob," said Jack, grinning. "It's what I wanted to do
myself. But I believe there is more to be gained by watching
Rollins--at least until we have more to go on."

"Probably," said Frank, "if we put it up to him now, he'd be able to
lie out of it."

"But he couldn't lie out of being seen with Remedios," said Bob. "Or
of using the radio."

"Frank is right, though," declared Jack. "Rollins would frame some
alibi, and all we'd succeed in doing would be to put him on his
guard."

Mr. Temple had been thinking deeply. Now he interrupted.

"Jack is probably correct in his surmise as to who Rollins was calling
by radio," he said. "Probably this Calomares ranch is headquarters for
the Mexican rebels who are making trouble for us. If it was the ranch
that Rollins called, he may have been making his report on today's
proceedings. But if he was calling the airplane, that is a more
serious matter. It may mean trouble for us tonight, perhaps another
attack."

"Great guns," grumbled Bob, "don't these birds ever sleep? Well,
believe me, if the Heinie that stole my airplane comes around where I
can get my hands on him, I'll fix him."

"You wouldn't hurt him, Bob, would you?" said Jack.

"Huh." That was all Bob replied. It was enough.

"I wouldn't do a thing to him, either," said Frank. "Except I'd turn
his Kaiser mustaches down so hard they'd never point up again."

Bob and Frank, joint owners of the airplane, grinned at each other.

"Well, fellows," said Jack, "We have got to sleep. So I propose that
we stand guard turn about tonight. It's pretty late now, midnight or
thereabouts, so that if we stand two hour watches, the three of us,
we'll pull through nicely without spoiling Mr. Temple's slumber."

The older man protested he was as able to stand a watch as any of
them, but the boys wouldn't have it so. Finally it was agreed that
Jack should take the first watch of two hours, Bob would succeed him
and Frank would have the last watch. The man keeping watch would sit
inside his bedroom door opening on to the gallery, with Jack's
revolver. As the bedrooms adjoined, while that of Rollins was the
last in the house, it would be easy enough to guard both.

The night passed, however, without incident.

It had been agreed beforehand that after the expiration of Frank's
watch at 6 o'clock there would be no necessity for keeping further
watch. Gabby Pete would be up and busy at his early morning tasks, and
the oil drillers housed in the bunkhouse also would be stirring about.
Therefore, after barring the door, a precaution Bob also had taken in
the room shared with his father, he turned in without awaking Jack.

Worn out by their trip of the day before with its attack and the
excitement of the night, all slept soundly, and Gabby Pete did not get
them up. It was almost 10 o'clock when Jack awoke. He called the
others, and soon all were dressed and ready for what the day would
bring forth.

Jack was the first dressed. He found Gabby Pete in the kitchen,
peeling potatoes, and asked if they could have breakfast.

"Sure thing," said Gabby Pete. "Have it fur you right away. Nice fresh
aigs an' ham an' coffee. How's that?"

"Fine. Have you seen Mr. Rollins this morning?"

"Yeah. Give him breakfast early. He lef word he hadda go over to
Number Two well where they're still drillin' an' hain't struck oil
yet, but said as how he'd be back later today. He tuk them two
drillers from the bunkhouse with him."

"Did you know Remedios sneaked up last night and took his flivver
again, right from under our noses?" Jack inquired.

"No, that so?" Gabby Pete dropped his paring knife and potatoes in
surprise.

"Well, he did," said Jack, starting to leave.

Gabby Pete jumped up, almost upsetting his pan in his haste, and
called to Jack to wait. Wiping his wet hands on a big blue apron that
looked incongruous on the old cowman, he pulled open a drawer in a
kitchen table and took out a flat blue envelope which he handed to
Jack.

"Almost forgot this," he said. "Your tellin' me about that there
scoundrel of a Greaser put everything else out o' my mind. Must be
gittin old an' forgetful. One o' these days I'll forgit my head."

He would have rambled on garrulously, but Jack interrupted. He turned
the envelope over curiously. It bore no address or writing of any
kind, and was sealed.

"What's this for, Pete?" Jack inquired.

"Oh, that's somethin' Mr. Rollins musta dropped out o' his pocket at
breakfast. Found it on the floor beside his chair after he was gone.
Will you give it to him?"

"All right."

Jack returned to join his companions.

"Have we any right to open this?" he said, after explaining how he had
obtained the envelope. "I for one believe that we should. It may
contain valuable information to us."

"You're right, Jack," said Mr. Temple. "I'm a partner in this oil
enterprise, and if one of our trusted employees is a scoundrel we are
entitled to know it. Give me the envelope. I'll take the
responsibility."

While the others looked on, Mr. Temple ran a knife along the edge and
slit the envelope open. Inside was a mass of documents and a letter.
Mr. Temple unfolded them, gave one look, then with an exclamation
jumped to his feet.

"Great Scott, boys," he cried. "This is important. Luck is certainly
with us."




CHAPTER XIV

THE KEY TO THE MYSTERY


"What is it?" cried Jack, pressing forward.

"Yes, tell us," demanded Bob and Frank as in one breath.

The three boys crowded around Mr. Temple, who in one hand held the
mass of documents and in the other the letter. He was reading the
latter.

"Boys," said he, "this proves Rollins's complicity in a plot against
us. But it makes matters more puzzling and complicated, too."

"How is that, sir?" Jack inquired.

"Well, first of all," said Mr. Temple, holding up the thick sheaf of
papers, "this is Mr. Hampton's own original list of the leases secured
by the group of independent oil operators to which I belong and which
he represents here in the field."

"Is it a copy of the list I recovered from the thief who stole it from
Mr. Hampton's house on Long Island?" asked Bob.

"No," smiled Mr. Temple. "It is the original. That was the copy. And
this letter with it is one written by Rollins to a man in New York
City who is one of the minor officials of the Oil Trust. It is too
long to read to you. But from it I gather that Rollins is a spy in the
employ of this official."

"Say, Dad," declared Bob, "this is too much for me. If the Octopus is
responsible for our troubles, then where do the Mexicans come in? And
vice versa?"

"That's what I had in mind, Bob, when I said this discovery
complicated matters," said Mr. Temple.

"Sh," warned Jack, from the window toward which he was glancing at
that moment. He sprang forward to see better. "Here comes Mr. Rollins
now. And in a tearing hurry, too."

Rollins jumped from his horse and ran along the porch to his room.
They heard the door slam, and then sounds of a furious searching being
carried on. The boys and Mr. Temple, gathered around the door and
window, looked at each other significantly.

"Found he dropped his papers and came back for them," whispered Frank.

A moment later Rollins called for Gabby Pete from the door of his
room. The cook hurried to him from the kitchen.

"Pete, did I drop an envelope--a long blue envelope--at breakfast?"
asked Rollins, making no attempt to conceal his anxiety.

Before Gabby Pete could reply, Jack stepped impulsively from the
doorway.

"Yes, you did," said he. "Pete gave it to me to keep for you."

"Where is it?" Rollins brusquely demanded.

"Step into my room," said Jack.

Rollins complied. When he saw Mr. Temple, Bob and Frank, he recoiled
as if to flee. But Jack barred the doorway. Rollins was speechless.
Mr. Temple advanced, holding out the document and the letter.

"Your duplicity is discovered, Rollins," he said. "I make no apology
for having opened your sealed envelope, because last night Jack
Hampton discovered you at the radio station with Remedios, and we knew
you were faithless to your trust. Come, make a clean breast of it."

Rollins's face went white.

"You, you read the letter?" he gasped.

Mr. Temple merely nodded.

Rollins seemed to shrink and grow older before their eyes. Suddenly he
sank into a chair. His shoulders sagged. Pressing his hands to his
eyes, he bent forward and began to cry. Not the noisy crying of a
child but great, dry, wrenching sobs.

"Come on, fellows," said Jack in a low voice. "Let's leave him to Mr.
Temple."

The older man nodded approval and the three boys filed out, closing
the door behind them. Simultaneously each drew a long breath of
relief. Bob was the first to speak.

"Dad'll get it out of him," he said

"I'm hungry," said Frank plaintively.

At that moment, Gabby Pete poked his head from the doorway of the
kitchen. Seeing the boys, he called:

"Come an' git it."

The three started on the run for the dining room, their youthful
spirits rebounding from the depressing scene in the room they had just
quit in answer to the tang of a perfect day and the cook's breakfast
call. Bob suddenly halted with an exclamation.

"How about Dad?"

"Oh, he's too busy to miss his breakfast," said Frank. "Anyhow, we can
get the cook to put up something for him."

"Yes, I'll speak to Pete about it," said Jack. "Come on."

They ate hungrily with little conversation. Pete hovered near and his
presence restrained them from talking about the topic that was
uppermost in their minds.

"How about taking a look at the radio plant?" asked Jack when they had
ended breakfast.

The others agreed eagerly. They were in the act of leaving the table
when Mr. Temple appeared. They crowded about him with questions.

"Easy, easy there," he protested. "I'm hungry as a hunter. Suppose
you boys wait outside for me while I get a bite, and then I'll join
you."

When Mr. Temple emerged, he lighted a cigar and leaned against a
pillar. The boys stood about him. For several moments he was silent,
staring out over the expanse of desert to the hills beyond, all
shimmering beneath the heat of the summer sun.

"It's a long story," he began, "but I'll simplify it for you. Rollins
held the key to the mystery. He has a family back East, an invalid
wife, a son in college, a daughter just preparing to enter college.
All that takes money, for doctor bills and school bills and clothes
for the girl. Rollins was a poor man on a salary.

"He needed money and couldn't see his way to getting it. Then a minor
official of the Octopus put temptation in his way by making him a
proposition. Mind you, he wasn't one of the big men of the Oil Trust.
I feel certain they know nothing about all this.

"This man proposed that Rollins obtain certain inside information
about the independent oil operators and sell it to him. Rollins wanted
to, but couldn't get the information. It was too closely guarded by
Mr. Hampton.

"It was then that another temptation came Rollins's way." Mr. Temple
paused. "A weak man seems to carry certain earmarks that draw
scoundrels to him, boys," he said. "It was so with Rollins. At this
moment a representative of Calomares, the Mexican landowner who is
backing the northern rebels, sought him out with a proposition that he
betray his employers. The rebels, as I suspected, wanted to make
trouble for President Obregon, of Mexico, by embroiling him with the
United States. And the way they wanted to set about it was by raiding
the independent oil operators. They needed a spy at our headquarters,
and they proposed that Rollins should become their man.

"Then Rollins had an inspiration. He told the Mexicans that if they
would help him, he would aid them. It was agreed. The agent who had
acted for Calomares in the negotiations was this German, Von Arnheim,
an aviator and a German secret agent in Mexico during the war. He took
the man Morales with him to Mr. Hampton's Long Island home to steal
the duplicate list of independent leases and other data which Rollins
had learned was kept there."

"That's where I came in," grinned Bob.

"Yes," said his father, "and it was because you foiled them that
Rollins came into possession of Mr. Hampton's own original copy of the
list and other data. For he stole it from Mr. Hampton's effects after
Von Arnheim and Morales had carried him away captive in our airplane."

"How about this attack on us yesterday?" asked Jack.

"As you suspected, it was for the purpose of capturing me, too," said
Mr. Temple. "And Rollins had let the bandits know when I would arrive.
Remedios was his go-between."

"Well," said Jack, "there's only one thing more."

"What is that?" asked Frank.

"Why, I'd like to know whom Rollins radioed to last night."

"I found that out, too," said Mr. Temple. "He was talking to the
Calomares ranch in Old Mexico, which has a very powerful station,
according to Rollins. He says the German, Von Arnheim, told him that
there are similar powerful radio stations scattered throughout Mexico
and South America, all built by German money for the use of its spy
system. And he said this German told him the most powerful station of
all was on an island in the Caribbean, and that it was so powerful it
could communicate with Nauen, Germany."

It was apparent that Mr. Temple had concluded his explanation, and Bob
and Frank began to ply him with questions. Jack, however, stood
silent, his face averted. Mr. Temple presently broke from the others
and laying a hand on Jack's shoulder whirled him about.

"Father?" asked he, in a kindly tone.

"Yes, sir."

"Well, Jack, I've got the beginnings of a plan in mind. But first I
must get more information from Rollins. Then I'll talk to you again."

Jack looked him squarely in the face.

"Mr. Temple," said he firmly, "I'm desperate. Father is everything in
the world to me. I'll wait to talk with you. But I tell you frankly
the only plan that appeals to me is to ride into Old Mexico and rescue
him."

The eyes of Bob and Frank, who had turned to listen, lighted up, and
they nodded vigorous approval. Mr. Temple stood off and looked at the
trio of husky fellows as if seeing them for the first time.

"Perhaps," said he, "that is what you will soon be doing."




CHAPTER XV

TO THE RESCUE


"I may be wrong," said Mr. Temple, thoughtfully, "in giving my
sanction to this plan to rescue Mr. Hampton. But I do not believe so.
And, all things considered, it seems the best if not the only way out.

"I have been accustomed to regard you as mere boys, but the conduct of
every one of you in our adventures lately shows me you are able to
think and act for yourselves. Yet I don't know. Jack, you and Frank
are motherless. But--if anything happened to Bob--his mother never
would forgive me."

"Say, Dad, forget it," grumbled the big fellow to hide his emotion. "I
can take care of myself."

His father's eyes lighted approvingly as they surveyed his truly
heroic frame.

"Yes, I guess you can," he said. "And you carry a cool head, too. At
any rate, I've given my approval."

He smiled whimsically, then looked from one to another of the three
eager young fellows.

"My daughter Delia was right," he said. "When I left home she said I
was wrong to think of you any more as youngsters, and that the first
thing I knew you would be making use of your wit and ingenuity to take
care of me. And now her words in a measure are coming true."

All four were grouped around the dining room table. For several hours
plans for the rescue of Mr. Hampton had been discussed and rejected.
Out of it had grown a plan which called for a daring invasion of the
enemy's territory by the boys.

Mr. Temple had impressed upon them the necessity for preventing the
United States government from being involved in the situation. He had
explained a number of angles not made clear before. Among other
considerations, he said, was the fact that practically all the Central
and South American republics were jealous of their big Yankee
neighbor.

"If our government were to make a hostile move toward Mexico," he
declared, "the other Latin republics would misconstrue our motives.
They would consider that because of our size we were acting the part
of the bully in order to reap financial benefit. They call us the
'Dollar Republic,' you know. Our interests in Central and South
America would suffer a severe setback."

Accordingly, it was distinctly up to the boys and Mr. Temple to effect
Mr. Hampton's rescue themselves. And out of the discussion had grown
the plan to have Jack, Bob and Frank make their way to the Calomares
ranch and offer their services to the rebel forces in the guise of
young Americans who were seeking adventure.

Once within the rebel stronghold they would bide their time and await
an opportunity to free Mr. Hampton and escape with him.

"I, for one, won't be content until I get back our airplane," said
Frank, when the details were being discussed. "Probably we shall be
able to recapture it, and then we can all four make our escape in it.
The 'plane carries three easily and can be made to carry four at a
pinch."

"Hurray for you," cried Jack, delightedly. "That's a real idea."

"I'll say so," declared Bob. "We can do it, too. I know we can."

Carried away by the boys' enthusiasm, Mr. Temple nodded approval.

Jack said he was certain enlistment in the rebel forces would offer no
difficulties. From Tom Bodine, the guard at the radio plant, with whom
he had had many conversations during the past two months about
conditions on the border, he had learned that adventurous young
Americans fought frequently on one side or another in the Mexican
revolutions.

"I can speak Spanish pretty well, too," Jack pointed out. "And Bob
and Frank have a smattering of the language, which they picked up from
me."

It was true. Two years before Jack had spent his summer vacation in
Peru where his father was engaged at the time in inspecting mining
properties. Jack had learned considerable Spanish during his stay and
on his return home had continued his studies of the language.
Moreover, he had aroused the interest of his chums to such an extent
that they also had begun to study Spanish. Often, when by themselves,
the three boys spoke to each other in the language. Spanish, by the
way, is the easiest of all foreign tongues to learn, as, unlike French
and Italian, all letters are sounded, and the grammar is very simple.

Mr. Temple was not to accompany the boys because, in the first place,
his age and distinguished appearance would arouse suspicion. Young
fellows riding in to enlist in the rebel forces was something that
could be understood. But in his case it would be a different matter.

He would stay at the ranch with Rollins, whom he decided to give
another chance. Rollins knew the business details of the oil
operations and unless he were retained the work could not go on. For
that reason, and also because he believed Rollins was truly repentant
for his treachery and would be faithful in the future, Mr. Temple
retained him.

Rollins had supplied valuable information for the expedition. He gave
the exact location of the Calomares ranch, in a valley amid low
mountains more than one hundred miles to the south.

There were two possibilities that the boys might be recognized for
what they were: if Remedios should arrive at rebel headquarters, or if
Von Arnheim or Morales recognized Bob as the youth who had foiled them
on Long Island. Neither was very likely. Remedios, they learned from
Rollins, had no intention of leaving the district because even if the
boys tried to cause his arrest he had a mysterious political pull with
the American officials, practically all of whom were of Mexican
descent. As for Morales and Von Arnheim they had had only a fleeting
glimpse of Bob and he could disguise his appearance sufficiently to
make that of no account.

"Well, boys," said Mr. Temple finally, "if we all were back in New
York under normal conditions I should consider this just about the
craziest notion ever, and never would consent to your carrying it out.
But out here, amid these changed surroundings, it seems the natural
thing to do. For the life of me I can't bring myself to feel any
alarm."

"That's right, Dad," said Bob. "Don't you worry. We'll be all right."

It was now late afternoon. Tom Bodine was to escort the boys to the
border as soon as darkness fell, making a big swing around Ransome,
so as to avoid notice, and set them on their way. They would travel by
horseback, all three having ridden since childhood. There were a
number of good mounts in the corral from which to select.

The boys planned to ride the major portion of the night until they
should reach a cave in the first of the Mexican foothills, where they
would spend the next day in hiding. Tom Bodine knew the cave of old
and was able to give the boys the location of certain landmarks which
would make it easy for them to find it. The following night they would
continue their journey, and this should bring them to the Calomares
ranch on the morning of the second day.

"Time to get ready," said Mr. Temple, looking at his watch. "And,
remember, the very first thing you must try to do is to get into their
radio station and call me. Day or night, the men here will be watching
for your signal and will call me. I'll be mighty anxious about you. So
remember."

"We shall call you, sir," said Jack, as the boys moved away. "And
don't worry. I'm sure we'll come out all right."




CHAPTER XVI

A SOUND IN THE SKY


"Good-bye, Tom."

"S'long, Jack."

"Keep a watch for our signal. We'll call you."

"I will that. An' if it's in trouble you are, Dave an' me'll be ridin'
just as fast as we can to help you. Wish you'd let me go 'long. I'm
half minded to follow you."

"No, no. We'll stand our best chance alone. They won't suspect we're
other than a bunch of wild young fellows out for adventure."

Tom grumbled, but the force of the reasoning was apparent to him. They
leaned from their horses for a last firm handclasp, then Jack rode on
to join Bob and Frank who sat on their horses some distance ahead.

"You're the boy to give it to 'em, Jack," called the big ex-cowboy in
a last farewell. "Give 'em thunder."

Jack waved a parting salute as he joined his comrades. Frank and Bob
did likewise. Then with night settling down over the vast desert waste
they rode on into old Mexico.

Beside the white stone marking the international boundary, Tom Bodine
sat his horse like a statue. Moodily he watched until they were out of
sight. It was a hard life Tom had led in his day and when he took the
job at the radio plant it was with a sigh of relief at the ease ahead
of him. But now despite his fifty years, the last thirty of which had
been filled with hard knocks, he felt the old call to adventure urging
him on.

With drooping head, he turned his horse toward home. But hardly had
the animal started forward, than he dragged it about again.

"Let's go," he shouted to the empty silence, and whirling his sombrero
aloft, brought it down on his horse's flank. Then he rode on after the
three figures that had been swallowed up in the darkness.

Far ahead of him, for Tom had taken considerable time to reach his
decision, rode the three companions. The young moon shed only a wan
and wraithlike radiance over the plain. They were alone, and the
parting with their last friend, combined with the solitude of the open
spaces, had its effect upon them. They rode awhile in subdued silence.
But not for long. Frank's lively spirits were the first to rebound.

"Race you to that rock," he cried, pointing to a solitary outcropping
of rock, about twice a man's height, about a quarter of a mile ahead.

"You're on," cried Jack, spurring his horse.

"Attaboy," yelled Bob, doing likewise.

With a shout that shattered the silence as if a band of wild Indians
were hitting the trail, the three boys dashed away.

Presently they pulled up by the rock, practically neck and neck. Their
eyes were alight now with the zest of adventure.

"Gee, it's great to be alive," cried Frank.

"You said it," declared Bob.

Jack nodded laughingly, but the next moment his face became grave.

"Just the same," he said, "we mustn't do that again."

"Why not?" demanded Bob.

"Well, for one thing, we must save our horses as much as possible. We
already have come twenty miles, and we have thirty miles more to go
before reaching Tom's cave."

"For one thing?" questioned Bob. "What's your other reason?"

"Just that we don't want to draw attention to ourselves."

"You're right, Jack," said Frank. "I'll not start anything again."

They jogged on.

A martial trio they made. Jack was clothed in the khaki shirt, riding
breeches, high laced leather boots and sombrero in which he had met
the boys on their arrival at Ransome. Bob and Frank were similarly
outfitted. Tom Bodine was about of Bob's proportions, and his partner
Dave Morningstar had the build of the slighter Frank. These two old
cow punchers had given the boys the run of their wardrobes. Each lad
carried an automatic at his hip swinging from a well-filled cartridge
belt. In addition, Jack bore his repeating rifle in a leather scabbard
on his saddle.

Frank cast an appraising eye over himself and his comrades, and
grinned with approval. Despite Jack's rebuke, he could not long keep
silence.

"Well, here we go, fellows," he said cheerfully, "just like the Three
Musketeers. Jack with your air of melancholy you can be Athos. Bob is
big enough to be Porthos, although I have got his appetite. I'm
Aramis."

"Aramis was always dreaming about the ladies," said Bob slily. "Heard
from Della lately?"

Frank was silent a moment under the sly dig, his thoughts flying back
to the faraway Long Island home. But his irrepressible spirits would
not permit him to remain silent for long, and soon he burst forth
again.

"All we need to make it complete," he said, "is D'Artagnan. I wonder
if we'll find him."

Jack made no answer. His thoughts were busy turning over plans for the
rescue of his father. Bob, too, was unusually silent, thinking of the
parting from his own father and the latter's anxiety which almost had
prevented his making this venture. Frank pursed his lips to whistle,
thought better of it, and jogged along as silent as his companions.

So they rode hour after hour, only the creak of leather, the
occasional stumble of a horse or the distant call of a coyote breaking
the stillness. At length a low range of foothills, upflung before
them, began to take shape out of the darkness with their near
approach. Presently Jack called a halt.

"Somewhere in there," said he, "lies Tom's cave."

It was in the early hours before dawn, when the darkness if anything
becomes more intense. A chill nipping wind long since had caused the
boys to unroll the rubber ponchos strapped to the back of their
saddles, and drape them over their shoulders. As they stood now in the
eerie darkness, striving vainly to locate the landmarks of tree and
rock which Tom had given them, the howl of a hunting coyote floated
down the wind. The sensitive Frank shivered.

"That sends the gooseflesh up my spine," he said.

"Are you scared?" asked Bob.

"I'm scared stiff," averred Frank. "My hair is standing up so straight
I wonder how my sombrero stays on."

"Me, too," said Bob.

"Liar," said Frank.

"You're another," said Bob. "You're not scared. I know you too well."

They grinned affectionately at each other. Jack who meantime had been
investigating, turned with a worried expression.

"I've followed Tom's directions faithfully," he said. "He said to lay
our course south by south-west and showed me what he meant on my
compass. I haven't deviated a hair's breadth. Somewhere about here
should be the first landmark--three rocks shaped like a camel lying
down. But I can't see them."

"Nothing to worry about in that," said Frank. "Probably we haven't
gone far enough. Let's push on."

"That must be it," said Jack with relief. "Well, come on."

Before they could get into motion, however, Bob uttered a warning
whisper.

"Listen," he said. "I heard a horse stumble behind us on the trail."

They listened breathlessly a moment, but no further sound was heard.

"Keep your guns handy," whispered Jack. Whenever the three were
together he took command. "Don't fire without cause, however," he
whispered. "If there is someone behind us, it may be another
traveller."

Again came the sound of a horse stumbling. All heard it distinctly.
Jack peered into the darkness and called firmly:

"Who are you?"

"Challenge him in Spanish, why don't you?" muttered Frank.

Before Jack could repeat his challenge, however, a familiar voice
replied:

"That you, Jack? This is Tom."

"Tom? Tom Bodine?"

"The same," replied the ex-cowboy, materializing out of the darkness,
and approaching. "And glad I am," he added, "to find you."

"But, good gracious, Tom, is anything the matter? Why are you here? I
thought we left you heading back for home five hours ago?"

"No, you just left me," said Tom. "That's all. I didn't head home,
because I wanted to come along. Been a-trailin' you all the way. And
here I am."

Jack was surprised, indeed. But now that Tom was with them, he
experienced a sense of relief. To venture into a strange land without
a guide, and in pitch darkness, besides, was a pretty stiff
undertaking. The responsibility of looking after his friends was no
light one.

"To tell the truth, Tom," Jack said, "I'm glad you came."

Bob and Frank echoed his words heartily.

"I had just about decided when you came up," Jack added, "that I had
lost my way. Frank thought, however, we merely hadn't gone far enough
to find your landmarks."

"He was right," said Tom. "You come straight as a die. All we got to
do is to ride on a piece an' we'll be in the snuggest cave ever you
see."

Riding two abreast, Tom and Jack in the lead and Frank and Bob close
behind, they pressed on another twenty minutes when Tom called a halt
to indicate a clump of rocks close at hand which suggested in their
outline a crouching camel. Then he led the way toward the left.

"Wait, wait," called Bob, in a tense voice that reached the ears of
all, and caused them to halt. "Keep your horses quiet and listen.
There. I was right."

All sat silent, and distinctly there came to their ears the hum of an
approaching airplane.




CHAPTER XVII

INSIDE THE CAVE


"What is it?" whispered Tom Bodine, to whom the sound was unfamiliar.
"Sounds like machinery of some kind."

"It's an airplane," Jack answered.

"Airplane? _An_ airplane?" said Bob, low voiced. "It's better than
that. It's our airplane, if I know anything."

"Righto, Bob," agreed Frank. "I'd know the old baby's voice a mile
off."

"They've shut off the motor," said Jack. "They must be going to land.
But where in the world could they land in these hills and in this
darkness, too?"

Tom Bodine slapped his knee.

"That's it," he said emphatically. "That must be it."

"What?" asked Jack.

"Why, there's a big level place just below the cave I was tellin' you
'bout. A plateau. Smooth as a floor."

The hum of the airplane had died away. The boys and their guide never
had caught sight of the machine in the darkness.

Suddenly Frank pointed in the direction whence the sound of the
airplane had come, ahead and slightly to the left.

"I thought I saw a light there," he whispered. "It was just a faint
streak of orange. Now it's gone."

"Look here," said Bob to Tom Bodine, "does that cave face this way or
is it on the other side of a hill?"

"It's on t'other side," answered Tom, "an' near the top."

"Well, I'll bet you there's somebody in that cave. And the light that
Frank saw was some kind of a signal to the airplane."

The big ex-cowboy scratched his head.

"Mebbe you're right," he said doubtfully. "I don't know 'bout such
things. But who'da thought that cave would be discovered. Why, I just
come on it accidental like onct when I was wanderin' through these
hills."

"Boys, there's only one thing to do," said Jack in a determined voice,
"and that's to investigate."

"Righto, Jack," said Frank eagerly. "Here's our chance to get back our
airplane."

"You said it," declared Bob. "Let's go."

"Not so fast," said Jack. "First we must have a plan of campaign.
Tom, what's the lay of the land? How far away is the cave? Would it be
better to leave our horses here and approach on foot?"

"Cave's not more'n half a mile from here," answered Tom. "It's just
around the shoulder o' this hill we're on right now and near the top.
I tole you 'bout that big rock in front o' the entrance an' them three
lonesome trees at the foot that give you a bee-line to the rock. Well,
we can git to them trees without bein' noticed an' tie our horses
there an' then sneak up afoot."

"Is there only the one entrance to the cave?"

"Only one," answered Tom. "There's a kind o' chimney up through the
rock to the top o' the hill. But nobody couldn't git out there in much
of a hurry. We won't have to worry 'bout that."

Frank had an idea.

"How far would those fellows in the airplane have to go to reach the
cave after landing?"

"Oh, le's see. 'Bout as fur as us, I reckon."

"Maybe we can cut them off before they enter the cave," said Frank.
"They'll be busy about the airplane for several minutes before they
start to make their way to the cave. How would they have to approach
the cave?"

"Same way as us from the trees on," said Tom.

"Well, if we hurry," Frank declared excitedly, "maybe we can capture
them before they reach the cave."

"Right you are, young feller," approved Tom. "But we'll have to leave
our horses behind or they might give us away. We can't tie 'em to
those trees like we planned."

"We can't hobble them," said Jack, thinking quickly, "because they
would wander aside a little distance, anyway. And we may want them
again in a hurry."

"Tell you what," said Tom, "seems like I remember a clump o' trees
just this side o' them three I spoke about. We can tie 'em there. An'
them fellers in the machine won't have no horses, so ours ain't likely
to nicker."

"Good," said Jack. "You lead the way and we'll follow."

Presently at a low-spoken word from the guide the boys dismounted and
tied up their horses. Then, Jack carrying his rifle, and the others
following close at his heels, revolvers in hand, they pressed on
toward the three trees forming Tom Bodine's landmark.

As they reached the trees, low exclamations burst from the boys.
Hitherto, they had been cut off from the plateau by the shoulder of
the hill. Now it lay below and before them. This of itself would not
have permitted them to see, as the darkness was intense. But now the
scene was illuminated by a number of oil flares stuck upright in the
ground in a rude circle.

And right in the middle of the circle was the airplane stolen from Bob
and Frank. There could be no mistaking the all-metal body nor the
peculiar wing spread, even at that distance of close to half a mile.

Several figures were moving about. As the boys looked on, these seized
oil flares and started moving toward them.

"Here's where our turn comes at last," said Frank.

Jack laid a hand on his arm.

"Better than that, Frank," he said. "How many do you make out?"

"Three is my guess."

"The two men in the airplane and the man in charge of the cave," said
Jack. "Dollars to doughnuts, the cave is undefended right this minute.
What do you say to capturing it and laying for them there?"

All four were grouped together, and consequently all heard Jack's
proposal. Bob and Tom Bodine agreed eagerly.

"Lead the way, then, Tom," said Jack, "because you know the route. And
be quick."

Swiftly, yet withal cautiously, because the cave might be defended,
they approached the big rock. As they sidled around it, a gleam of
light from the mouth of the cave at the rear of the rock fell athwart
their path. Involuntarily they drew back.

Then Jack brushed Tom Bodine aside and took the lead. His repeater
thrust before him, crouching, he entered the mouth of the cave. A
moment later his whisper came back:

"Coast's clear."

But the others already were at his heels.

A hasty glance around revealed the first of the two chambers, which
Tom had said the cave possessed, was luxuriously furnished and lighted
by a powerful electric bulb enclosed in a huge frosted globe suspended
from the middle of the roof. There was no time for further
investigation because Jack already was pushing on toward the heavy
hangings at the rear covering the mouth of the second chamber, and the
others clung to his heels.

Parting the hangings quickly, Jack threw his rifle to his shoulder.
Then he and his companions received their second big surprise. The
room was empty of human occupants. But it, too, was brilliantly
lighted.

And it was a radio broadcasting station.

To the trained eyes of the boys that much was apparent at first
glance. In one corner of the tremendous cave hummed the dynamo. From
it, of course, came also the electricity for the lights. Before they
could pursue their investigations, however, Tom Bodine, who had
dropped back to the outer entrance, issued a warning hiss. Then he
darted across the outer room and joined them.

"Three of 'em," he whispered. "They'll be here in a minute."

"Good," said Jack, taking command. "We'll give them a surprise. These
hangings are fastened to rings on a big pole up above us there, and
they'll slide easily. Tom, you and Bob grab the hangings in the middle
and be ready to pull them aside when I say the word. Frank, you and I
will stand here in the middle and keep them covered."

All took their assigned positions as the sound of voices was heard at
the outer entrance. Jack peered between the two folds of the hangings
and smiled with satisfaction.

"Let's go," he said.

The hangings flew aside.




CHAPTER XVIII

THE FIGHT IN THE CAVE


"Hands up, gentlemen," ordered Jack, rifle to shoulder.

"And be quick about it," added Frank, revolver extended.

Tom and Bob, the hangings disposed of, ranged themselves on either
side of the pair. Four weapons covered the group in the outer room.

The three men, who had advanced well to the center of the room, stared
dumbfounded at these apparitions. Then amazement gave place to anger,
and one of the trio made a move as if to draw his revolver.

"None of that," commanded Jack, sternly. "Up with them quick or I'll
shoot."

Three pairs of hands were unwillingly elevated. Two of the men wore
sheepskin jackets and leather helmets and the boys surmised correctly
that they had been up in the airplane. Bob felt certain they were
Morales and Von Arnheim, the two who had made the trip to the East to
steal Mr. Hampton's papers and whom he had foiled in that purpose, but
who had succeeded in stealing the airplane and making their way to
Mexico in it. The other was a rangy man of about twenty-six, keen and
shrewd-looking, and had the appearance of an American. Evidently he
was the guardian of the cave. And it was he who had moved to draw his
weapon when surprised. A tough customer and one to be watched, thought
the boys.

"Face about," ordered Jack.

They obeyed.

"Keep them covered, Tom," Jack then commanded. "Well search them."

With weapons held ready, the three boys advanced. At that moment, the
caretaker of the cave took one step forward and instantly the lights
in both rooms faded out and the cave was in inky darkness.

He had pressed a button in the floor, switching off the lights.

The boys were so taken by surprise that for a moment they did not
fire. Neither did Tom, for fear of hitting them as they were in front
of him. This gave their three enemies an opportunity to shift position
and fling themselves prone.

When after their surprise, the boys did fire, their bullets merely
pinged against the distant wall and did no damage. But the flash of
their weapons betrayed their positions and answering bullets came
uncomfortably close. One swept Jack's hat from his head.

From behind them Tom Bodine's revolver spoke, as the enemy thus
betrayed themselves. The soft thud of a bullet striking flesh, a
groan, choked off in the middle, a hasty scrambling to get away from
the danger point on the part of the man struck, then silence.

This silence was so profound the boys seemed to hear the beating of
their own hearts, and tried to hold their breath for fear of betrayal.
They had thrown themselves prone after the first volley and lay so
close they were touching, Jack in the middle.

Each side was fearful now of firing at the other, lest the flashes
give their position and an answering bullet find its mark.

Jack thought quickly. Putting his lips to the ear of each of his
companions in turn, he whispered:

"Wait till I get Tom and come back. Then we'll make our way to the
entrance."

Each signified by the pressure of a hand that he understood. Certainly
it would not do to have the enemy escape and thus cut them off in the
cave!

Slowly, carefully, noiselessly, Jack wormed his way to the rear and
when he considered he must be in Tom Bodine's neighborhood he began
whispering in a tone that could not be heard more than three feet
away:

"Tom. Tom. Tom."

A hand gripped his leg. A voice whispered so low it was barely audible
to him:

"That you, Jack?"

"Yes. Listen."

Running a hand over Tom Bodine's body, Jack found his ear and, as he
had done with Bob and Frank, set his lips to it. He explained his
purpose to gain the entrance to the cave and prevent being bottled up.
Tom nodded approval, and Jack was about to return to his companions
when he suddenly thought of the radio room beyond, and its
possibilities. It would never do to leave that unguarded. Their
enemies could telephone the Calomares ranch. Then, even if the boys
escaped, their identities would have become known at rebel
headquarters. Their chances of rescuing Mr. Hampton would go
glimmering.

Once more Jack set his lips to Tom's ear and explained the situation.

"That's right," whispered Tom in return. "Tell you what. I'll guard
this here inner room from behind the rocks in this doorway. You three
stop up the outer entrance, an' well have 'em bottled."

Jack made his way back to his comrades, and the three started
crawling. They moved inch by inch, so as to avoid bumping into
furniture--a number of heavy chairs had been seen standing about the
great room.

Jack was in the lead, Frank at his heels, Bob bringing up the rear.
Cautiously, tortuously, they made their way ahead for what seemed like
ages, pausing frequently to listen.

After one such pause, as he again started to follow Frank, Bob felt a
form brush against him from the side. Then an arm shot out and
encircled his neck. Bob wriggled about to face his opponent and threw
both arms about him in a mighty clasp.

As they fell to the floor, Bob heard a strangled cry from Frank and a
grunt from Jack. They, too, had come to grips with the enemy. Their
three opponents had started for the door with the same purpose held by
the boys--that of bottling up the other side. The two crawling trios
had brushed against each other in the middle of the floor.

Now three individual fights raged furiously on the floor of the cave
in Stygian darkness. Every man fought for his very life. The sob of
labored breathing was the only sound--that and the threshing about of
bodies.

Tom Bodine was sick with rage at his helplessness, for he dared not
shoot lest he hit one of the boys, and he could not see to take a
hand. He decided to try to find that button in the middle of the floor
of the outer cave which the enemy had used to throw off the lights.
If not that, perhaps there was a wall switch somewhere. In his pockets
was a box of safety matches. With these in his hands he started for
what he thought was the middle of the room.

Recklessly Tom struck and lighted matches, searching the floor for
that button, stopping after each match burned down to his fingers to
listen to the panting, heaving struggle going on about him.

At last he found the button and pressed it. Light once more flooded
both caves, dazzling to the eye after the pitch darkness of the moment
before. Jack and Frank were still tightly locked with their respective
foemen. But at the very moment the lights were switched on, Bob got
the upper hand of his man with a famous hold he had used to advantage
in winning his wrestling fame at school. There was a heave, and then
Bob straightened up and the other went hurtling through the air. He
was the American of the enemy trio.

The man fell on his left side, a yard or more away, by a quick twist
avoiding the descent on his head, which is the usual result of such a
wrestling toss. His right arm was outflung and, as he skidded along
the floor, the fingers of his right hand came in contact with a
revolver dropped by one of the wrestlers.

Twisting about like a cat, with a convulsive movement, the man came to
his knees and fired. There was a warning shout to Bob from Tom Bodine.
But the man's aim was far from steady, and the shot went wide.

Bob leaped forward as if shot from a catapult, letting out a wild yell
as he did so. It was a tremendous leap from a standing position, and
he descended feet first on the other before he could discharge the
revolver again. Beneath the impact of Bob's weight the man went down
like a shot rabbit and lay still. Bob disarmed him, turned him on his
face, pulled his arms behind him and began tying them with his belt.

Meantime Jack was getting the better of his man, the Mexican. But
Frank, slightest of the three boys, was putting up a losing fight
against the German. The latter had him down and was kneeling on his
chest with his hands throttling the boy. Frank's face was purple and
the breath was whistling in his throat, while his efforts to throw the
other off were becoming more and more feeble.

Tom Bodine took in the situation and sprang forward, clubbing his
revolver. He brought it down on the German's head. There was a
sickening thud. One blow was enough. The German's hands relaxed their
grip on Frank's throat, and he rolled over unconscious.

At the same moment Jack pinioned the arms of the Mexican, and the
latter lay helpless.

The fight was over.




CHAPTER XIX

RESTING UP


Swiftly Tom Bodine trussed up the unconscious German with the man's
own belt, while Jack similarly treated the thoroughly cowed Mexican,
Morales. Meanwhile, Bob went to Frank's aid, assisting him to a chair,
bringing him water from a spring in a corner of the inner cave and
fanning him with his sombrero.

None of the three boys had suffered more serious injuries than
bruises, but Frank had been badly battered in the encounter with his
heavier opponent and the muscles of his left shoulder had been
severely strained.

Despite the mauling he had received, Frank wanted to go and inspect
his beloved airplane at once and Bob, the co-owner with him, was
equally eager. Jack, however, protested.

"No, sir," said he firmly, "you are in no condition to go chasing off
down this rocky slope. The airplane isn't going to fly away. It's in a
pocket in the hills that nobody is going to discover. And, anyhow,
there is nobody around in this desert place to do any discovering.

"Moreover," he continued, "it is almost morning now. We all have been
riding all night and with this fight coming on top of everything else,
we are thoroughly tired out. So, instead of any more conversation
tonight, I propose that we turn in and go to sleep, leaving one man on
guard. At the end of two hours he can call another fellow, and in that
way we can all get four or five hours sleep. I'll take the first watch
and--"

At that moment a groan from one of the prisoners on the other side of
the room interrupted, and with an exclamation Bob started forward.

"Good gracious," he said, "I'd forgotten all about that chap. His arm
felt wet and sticky when we were wrestling and I believe he's the man
Tom wounded with that first shot in the darkness."

Bending over his late opponent, Bob noted a dark brown stain on the
left shoulder of his coat.

"Only a flesh wound, I reckon," said the other. "But it sure hurts.
Are you going to leave me like this?"

Bob flushed.

"Of course not," he said. "What do you think I am? Here, let me help
you up and we'll have a look at it."

Bob assisted the other to a chair. His hands were then untied, the
coat sleeve cut away and an examination made of his injury. It proved
not serious. The man told Bob where to find a bottle of iodine. He
winced under the sting of its application, but made no outcry. Then a
rough bandage was made of clean handkerchiefs, and the boys stood back
to examine their handiwork, for all had taken part in the operation.

"You're some fighter, kid," the other said approvingly to Bob. "But I
reckon I'da got you at that if it hadn't been for that arm."

"Maybe so," Bob modestly agreed. "You put up a stiff fight."

"You're an American, aren't you?" asked Frank. "What's your name? And
how do you happen to be with these fellows?"

"Why not?" said the other, answering the last question first. "I'm a
rolling stone and joined up with this outfit because it looked like
something doing. And that's what I want. As for my name, it's Roy
Stone. And you guessed right. I am an American. Born an' raised in
Wooster, out in Ohio."

He paused and looked curiously from one to the other of the boys. Tom
Bodine was examining the two other prisoners for possible injuries
needing attention. Stone nodded toward him.

"I can place a fellow like that, all right," he said. "Know this kind
down here on the border. But who are you? You're only kids. What's
your game? Are you with Obregon?"

"No, indeed," said Bob. Turning to Jack, he whispered:

"Is it safe to tell him who we are? He's an American. And, somehow, I
have an idea he might help us."

"Well, it won't hurt, I guess," said Jack, doubtfully. "He might
escape and betray us to rebel headquarters, but I suspect we can guard
against that. Besides, he's bound to find out our identities, because
those other two chaps will recognize you."

"Hardly in this rig," said Bob, referring to his clothing. "We talked
all that over, you remember."

"That's right. I had forgotten."

Bob and Jack had drawn aside during the whispered colloquy. Now Bob
turned back to his prisoner.

"Look here," he said. "We'll have a little talk later. Right now we
all need a good sleep."

Without more ado, Bob and Frank tied Stone's hands and led him to his
bed, behind a curtain in one corner of the outer room. They considered
that inasmuch as he was wounded, he was entitled to the bed. The
German had recovered consciousness from the blow on the head dealt him
by Tom, and the latter already had ranged him and the Mexican along
the wall where the sentinel could keep an eye on them. For
themselves, the boys pulled a heavy rug to another portion of the
wall, spread the heavy hangings formerly covering the door to the
inner cave on top, and here Bob and Frank lay down with their ponchos
over them. Presently they were joined by Jack who had planned to mount
guard the first two hours, but who had been overruled by Tom Bodine.

"No, you don't," said the latter. "I'm a tougher bird than you, and I
take this job myself, an' that goes."

Too tired to protest very vehemently, Jack turned in after exacting a
promise that Tom would call him at the end of two hours. The old
cowman, however, had no such intention. It was not until eight hours
later that he summoned Jack. The lights in the cave still burned
brightly, for Tom had refrained from switching them off for the
obvious reason that they made it easy to keep an eye on the prisoners.
Day-light, however, showed at the mouth of the cave. When Jack noted
the time, he began to scold.

"Forgit it," said Tom Bodine, gruffly. "You boys needed a good sleep
while I'm an old hand at ridin' night herd. It didn't bother me none
to stay up."

Without further words, he turned in and was asleep almost on the
instant. Jack roused Bob and Frank, and while Bob mounted guard at the
mouth of the cave where he could keep watch both on their prisoners
and on the approach from below, the two others explored a rude pantry
behind a curtain. They found a plentiful stock of provisions, which
made it unnecessary for them to draw upon their own limited food
supplies for breakfast.

When they themselves had eaten, they released the captives one at a
time and fed them, afterwards replacing their bonds. The Mexican and
the German were surly and uncommunicative. The latter tried to ply
them with questions, but when they refused to answer he adopted a
bullying tone and threatened them with all sorts of dire punishment.
His threats, however, were no more effective at breaking down their
silence than were his questions.

Bob remained at the doorway to avoid the risk of recognition by
Morales and Von Arnheim as the youth who had foiled their attempt to
steal Mr. Hampton's papers from his Long Island home. Jack, who had no
means of knowing how much the traitor, Rollins, might have told Von
Arnheim in the past about Mr. Hampton's personal affairs, watched
keenly for some indication on the German's part that he had formed an
idea as to their identity, but none was forthcoming.

Jack was correspondingly elated.

"I suppose," he said to Frank, after Morales and Von Arnheim had been
fed and returned to the other side of the cave, "that Rollins never
bothered to speak about us because we were just boys. Then, too, you
fellows arrived only the very day that we discovered Rollins's
treachery and put a stop to his communications with these people."

"That may all be true," said Frank. "Probably it is. Just the same,
Von Arnheim and Morales are bound to put two and two together and make
a shrewd guess as to our identities, even if they say nothing to us
about the matter.

"But," he added, confidently, "what if they do? We have them prisoners
now and if we keep them well guarded until we have rescued your
father, what does it matter how much they know?"

Jack nodded agreement.

"We'll have to keep mighty strict watch, though," he said. "Well, now
let's feed this American, Stone. I'll draw straws with you to see who
keeps guard while Bob comes to get his breakfast at the same time. He
wants to talk to Stone, he said."




CHAPTER XX

CONFERRING BY RADIO


Bob, however, told his companions he had decided not to interview
Stone for the time being, and explained his reason, as well as what he
hoped to gain from conversation with the prisoner.

"I believe," he declared, "that Stone is a warm-hearted, adventurous
young fellow with no particular love for the Mexican rebels, but
merely serving under their banner for the excitement. And I believe if
we approach him right we can win his help in rescuing Mr. Hampton. He
must know a good deal about this Calomares ranch and if we can get him
to give us some pointers it will be worth while.

"That was what I had in mind last night. But mounting guard here this
morning I had time to think it over, and I decided we had better go
slow and, if possible, get the advice of my father on the matter."

"But how could you do that?" asked Frank. "Go back to Hampton ranch
again?"

Jack interrupted excitedly.

"No, Frank, don't you see!" he said. "Bob is thinking of the radio
here in the cave. Aren't you, Bob? I'm a simpleton not to have thought
of it before."

"Well," said Bob, "we've all been so excited, that's not to be
wondered at. But while I mounted guard here during your breakfast, I
had a chance to calm down and do some thinking."

Bob was eager to use the radio telephone at once, but Jack persuaded
him to eat breakfast first. The big fellow literally bolted his bacon,
bread and coffee, and then accompanied by Jack, while Frank mounted
guard, he retired to the inner room where the radio outfit was
located.

"Let's have a look around here before we try to telephone," said Jack.
"It will take us only a few minutes. And we ought to know what we have
captured. What say?"

"Fair enough," Bob agreed.

A cursory inspection quickly convinced Jack that the station was not
of recent installation, but had been put in about the year 1918. Much
of the equipment, while of the best at the time it was put in, had
been antiquated since by improved parts.

It was a complete two-way installation, however, comprising a
generator of practically sustained waves, a good control system to
modulate the output, and a ground system for radiating a portion of
the modulated energy as well as a receiver and a good amplifier.

"Here is this chimney in the rock about which Tom spoke," Jack pointed
out. "They have hooked up through this. And the antenna, I suppose, is
on top of the rock above us.

"This arc," he continued, advancing to the coils, "looks pretty strong
and seems to have a rather elaborate water-cooling system. I think it
is of foreign design, probably German. The Germans were early in the
field with radio telephony development, you know."

"All right," said Bob, who was beginning to grow impatient, "I'll take
your word for it. But what I want to know is, can we telephone my
father at your ranch?"

"Say, Bob, I'm sorry," Jack said quickly. "You know how crazy Dad and
I are over this radio telephone. But, of course, you are anxious to
get your father. Come on, let's try. I'll throw on the generator."

Suiting action to words, Jack shortly had the generator at work, while
Bob began calling through the air for his father.

"Be careful to use our code," Jack warned him. "You know Rollins said
these fellows had a powerful radio station at the Calomares ranch, and
if they were to pick up your call and listen in there'd be trouble."

"Right," said Bob. "But if Dave answers the signal, I'll have to ask
for father, because Dave doesn't understand the code."

It was Dave Morningstar who answered, the other ex-cowboy employed as
mechanic and guard at Mr. Hampton's radio plant in New Mexico. And
when he had tuned to the proper pitch to hear distinctly and Bob's
voice greeted him he was so surprised he stuttered and was incapable
for a moment of coherent speech. Then he began to pour a flood of
questions at Bob, wanting to know where he was, how he happened to be
able to radio, what had happened to the boys, why Tom Bodine, his
partner, had failed to return, and so on. But Bob cut him short.

"Stop it, Dave," he said. "We may be overheard. Call father to the
telephone, so I can speak in code. Then I'll explain."

Fortunately, although it was past noon, Mr. Temple was at hand. So
anxious was he about the boys that he had been unable to sleep during
the night. All morning, despite the belief that it was folly to expect
to hear from the lads so early, he had stayed at the radio plant. Now,
when he heard his son's voice, there was heartfelt thanksgiving in his
reply.

"Is it really you, Bob?" he asked, speaking in code. "I must have
been insane to let you three lads go off on such a foolish venture. I
have been tortured with anxiety every minute since you left. Tell me
where you are and what has happened. And how in the world is it
possible for you to radio? Are you all right?"

"Yes, we're all right, Dad," answered Bob, and there was a good deal
of emotion in his voice, too. The big fellow and his father were real
pals. "Don't you worry, Dad," he added. "We're doing well, thank you."

Then he retailed their adventures from the time of crossing the border
into Old Mexico and leaving Tom Bodine at the boundary. There were
many interruptions from his father.

"Thank heaven," said the latter, when learning that Tom Bodine had
followed the boys and joined them. "He's a trustworthy chap, and to
know that he is with you makes me breathe more easily."

When he came to relate the fight in the cave, Bob diplomatically made
little of it. He felt there was nothing to be gained by unnecessarily
harrowing the feelings of his father. The latter's anxiety, however,
was great and he pumped rapid questions at his son which Bob could not
avoid answering. The result was that Mr. Temple gained a fairly
accurate idea of the peril in which the boys had been involved.

"But, Dad," Bob interrupted his parent's horrified exclamations,
"it's all over now. None of us is injured, and we have got back our
airplane."

"I know, Bob, I know," answered the older man. "But you can't
understand a father's feelings. And it isn't all over yet by any
means, for you haven't rescued Mr. Hampton. And you don't know what
difficulties you will encounter in doing so, and what dangers you will
run."

"Oh, I believe the worst is over, Dad," answered Bob. "We have
captured Morales and Von Arnheim, and they were our two worst dangers.
If we had encountered them at rebel headquarters and they had
recognized me, our goose would have been cooked. We would have been
taken prisoners, too. But now there will be nobody to recognize us.
The rebels will take us for what we pretend to be, young Americans
seeking adventure and riding in to enlist."

"Perhaps, Bob," said his father, only half convinced. "But let me
think this over. There ought to be some other way to rescue Mr.
Hampton now that you have the airplane again. Also you have these
prisoners. It may be that you can gain some valuable information from
them. Have you questioned them yet?"

"That's just what I was coming to, Dad," said Bob.

Thereupon he proceeded to tell his father of Roy Stone, the young
American in charge of the radio plant in the cave, whom they had made
prisoner. A lengthy conversation ensued. Mr. Temple was reluctant at
first to have the boys reveal their identities inasmuch as so far they
had escaped detection. But he saw that if an ally could be made of
Stone it would be of the highest importance to the boys. He finally
authorized Bob to promise Stone a suitable reward, if he thought that
would appeal to him. Then, enjoining Bob to take no further steps
without first consulting him by radio, Mr. Temple concluded the
conversation.

To Jack and Frank, speaking in low tones at the entrance to the cave
where Frank kept guard, Bob explained the gist of his conversation
with his father. Tom Bodine still slumbered heavily. Stone lay napping
on his bed. Morales and Von Arnheim sat with drooping heads in the
heavy chairs where, while Bob telephoned, Jack had thought it best to
bind them.

"Well, let's talk with Stone and see what he has to say," Jack said.
"Frank and I have been talking the situation over, too, and we've got
all sorts of ideas. For one thing, we thought there was a chance the
rebels could be persuaded to exchange father for Von Arnheim and
Morales. Stone might know how important those two worthies are
considered by the rebels."

"Can't I listen in on this confab?" Frank asked, plaintively. "Or
must I continue to mount guard here? Besides, I want to go down and
look at our airplane, and pat it even if I can't get in and fly. I can
see it from here, and it looks tempting."

"You'll have to wait awhile to do that, I expect," said Jack with a
smile. "We must decide what to do next before we spend any time
playing."

At that moment, Tom Bodine yawned prodigiously and sat up on his
make-shift couch.

"At least I can have a voice in the conference," said Frank. "If Tom's
awake he can mount guard."

"All right, fine," said Jack. "We'll leave him out here with Morales
and Von Arnheim, as soon as he has had something to eat. Then the
three of us can take Stone into the other room and have a talk with
him."

So it was arranged.




CHAPTER XXI

GAINING AN ALLY


Before mounting guard, however, Tom thought of their horses, a detail
which the boys had forgotten in the quick march of events. He and Bob
descended the slope, brought the animals into the valley where there
was grass along the bed of a little stream trickling from a spring,
and a few trees that provided shade. The horses were hobbled to
prevent wandering too far, and then left to do as they pleased. They
pleased, every one, to lie down at once and roll.

Upon their return to the cave, after Bob first had inspected the
airplane and found it in tiptop condition and stocked with gas and
oil, Tom mounted guard while the boys carried out their intention of
taking Stone into the inner room for a conference.

Stone made matters easy for all concerned by speaking first, as soon
as they all were out of earshot of Morales and Von Arnheim, and
telling the boys he had guessed their identities.

"Of course, I don't know your names," he said, "but I reckon one of
you is the son of that American bigbug old Calomares is holding
prisoner up at his ranch. And the rest of you are his pals."

Bob's face fell. He had believed their identities were unsuspected. If
this man could draw so clever a deduction, then their two other
prisoners could do likewise. Moreover, if they carried out their
original plan and went to rebel headquarters to enlist, would they not
there, too, be suspected?

"Do the others guess who we are?" he asked.

"Don't know," said Stone. "I haven't been given much chance to talk to
'em, have I? But that German is smart, and he may suspect. But"--and
with this statement he set at rest a part of Bob's fears--"my bed is
pretty close to this room an' I have pretty good ears. I overheard
some things that Morales and Von Arnheim couldn't hear, especially
when you used the radio to call your father. Anyhow, I thought it was
your father. Mostly you spoke in code, but I heard you call him 'Dad'
a couple of times."

The three chums looked at each other, nonplussed. Stone laughed.

"Until I made out who you were," he said, "I thought you were some
wild-eyed kids looking for adventure an' comin' to the right place to
find it. But once I got a suspicion, it was easy to figure out the
rest. You see, I knew about your owning the airplane that Von Arnheim
stole, an' about your radio stations. When you started the generator
that showed me you knew something about radio, an' that was another
clue.

"So I just put two an' two together. Anyhow, it finally came to me who
you were. Am I right?"

"Yes," said Jack, taking the initiative as Stone concluded, "you are
correct. It is my father who is held prisoner by the Mexicans, and
these are my chums."

Jack regarded the other searchingly.

"We're in trouble," he said, simply, "and we need help that you could
give us. How closely are you tied up with the rebels? You're an
American and we are Americans. Does that mean anything to you?"

"Yes, kid, it does," said Stone. Despite the fact that he was only
seven or eight years older than the three chums, he had led a roving
life that had given him a world of experience and an older viewpoint,
and he persisted in regarding them as youngsters. "I'm strong for the
good old U.S.A.," he continued.

"But don't get me wrong. These are fine people down here, and don't
you believe they ain't. Their standards aren't American standards
either in manners or politics. But, just the same, they're good folks,
and don't you let anybody tell you different. I wouldn't turn against
them for anything. So, although your fathers have lots of
money"--here he looked fixedly at Bob, who felt uncomfortable
remembering his father's authorization to offer Stone money to help
them--"well, don't offer me any, that's all."

Bob was silent, but Jack again stepped into the breach.

"Good for you," he said warmly. "I'm glad to hear you talk that way.
But"--and here Jack paused impressively--"suppose the imprisonment of
my father threatened the peace and prosperity of the 'good old U.S.A.'
as you call it. What then?"

Stone looked troubled.

"See here," he said. "What are you driving at?"

"Shall we tell him what Mr. Temple says is behind all this?" Jack
asked his companions.

Bob and Frank nodded agreement.

"Well," began Jack, "it's this way." Thereupon he proceeded to relate
Mr. Temple's theory that the attacks on the independent oil operators,
the capturing of Mr. Hampton and the attempt engineered by Rollins and
Remedios to capture himself, were all part of a plan to embroil the
United States government with President Obregon, as the responsible
head of the country whence the outrages originated.

"And Mr. Temple says," concluded Jack, "that if the two countries did
come to war, it would hurt us very much with all Latin-America."

"Sure would," agreed Stone thoughtfully. "I've knocked about among
these Spanish-American republics for years, an' they all look on the
little old U.S.A. as a dollar-chaser and a bully." He was silent for a
moment, and when he resumed, he said: "Look here. What you've just
told me makes a big difference. You haven't said yet what you are out
to do. But I can make a pretty good guess. You're going to try to
rescue your father without letting the American authorities know
anything about it. Am I right?"

Jack nodded.

"Well, I'll help you," said Stone. "I know where he is and how to get
him, an' I'll tell you all I know."

"Hurray," yelled Frank, the impulsive.

Jack and Bob contented themselves with grasping Stone's hand warmly.
Realizing Stone still was bound, Bob pulled out a pocket knife and
started to cut his bonds, but Stone made him desist.

"Keep this dark from Von Arnheim and Morales," he said. "And keep me
tied up. They may suspect I'm throwing in with you, but I don't want
'em to know. I want to be able to make a getaway, because these parts
won't be very pleasant for me hereafter."

"That's right," said Bob. "Well, even if you won't take money, you'll
have to let my father or Mr. Hampton help you in some way, with a job
or something."

Stone smiled tolerantly.

"Buddy," said he, "getting along is the least of my troubles."

With Stone's aid won, the boys now set about learning from him how
matters stood at the Calomares ranch.

For hours they continued to talk, so absorbed that they did not
realize the flight of time until Tom Bodine came to inform them the
sun was near setting and to ask what they intended to do that night.
By then, however, they had obtained from Stone all the information he
could give them, which was considerable; Bob had had another talk by
radio with his father, and a plan for further proceedings had been
worked out.

Jack and Bob were to make the attempt at the rescue of Mr. Hampton
alone. They were to fly to the Calomares ranch in the airplane with
Bob at the wheel, as Jack was not so experienced a flyer. Bob, on the
other hand, knew his machine thoroughly, and was familiar with its
every trick, a knowledge much to be desired as airplanes even more
than motor cars and ships develop temperament and have got to be
"humored," so to speak.

Frank rebelled at the part assigned him. He was to stay behind at the
cave with Tom Bodine and Roy Stone, guarding the prisoners, Morales
and Von Arnheim. When they had rescued Mr. Hampton, Jack and Bob would
take him in the airplane and start flying to the Hampton ranch.

By means of the radio in the airplane, which could send 150 to 200
miles, although it could receive messages from a much greater
distance, the Hamptons and Bob would notify the party left behind in
the cave. Then Frank, Tom Bodine and Stone would ride for the border
on horseback. Morales and Von Arnheim would be left bound so as to
prevent their giving an alarm or offering any interference with the
programme. After the party had been given time to make its way well
along toward the border, rebel headquarters was to be notified by
radio from the Hampton ranch of the location of the prisoners. The
latter would, therefore, suffer nothing but inconvenience.

"But what fun do I get out of this?" lamented Frank, enviously
regarding Bob and Jack. "You fellows get all the fun and all the
glory. I ride tamely back to the ranch."

"It is hard luck, Frank," said Bob. "But your shoulder is sore and
aching from your fight last night, and I'm in better condition to
operate the plane. Besides, you know we can't take you, as the plane
will hold only three and when we get Mr. Hampton we'll have our full
complement. Some one of us has to stay behind. You've had your share
of the fun so far, anyhow, and your turn will come again."

"I don't see it," said Frank. "It looks to me as if when you rescue
Mr. Hampton the fun will all be over. But that's the way with you big
bullies. Always picking on the little fellow."

"Well, you see," said Bob mischievously, "I've got to keep you out of
danger for Della's sake. Ouch! Wow! Letup. Can't you take a joke."

For, lame shoulder notwithstanding, Frank leaped and, bowling the big
fellow out of his chair, got astride of his writhing body and began to
pummel him.




CHAPTER XXII

FLYING TO THE RESCUE


"Come on. Strip."

It was Bob talking, and the command was addressed to Morales and Von
Arnheim. Tom Bodine stood guard over them with leveled revolver.

"But, why?" protested Von Arnheim.

"Ask us no questions an' we'll tell you no lies," said Tom, waving his
weapon. "Jest do what you're tole."

Sullenly the two men obeyed. When their outer clothing had been
removed, and they stood revealed in light-weight undergarments--a well
set-up powerful pair of men, about the height of Jack and Bob although
neither was so sturdy as the latter--Bob halted them.

"That's enough," he said. "Here put these around you."

And he tossed them rubber ponchos which they threw around their
shoulders.

Scooping up the discarded clothing of the two men, Bob and Jack
retired to the radio room. Stripping quickly, Jack dressed in Morales'
clothing and Bob in that of the German aviator. This arrangement was
adopted because Jack could speak Spanish with considerable fluency and
thus fitted into the role of the Mexican. Bob, on the other hand, was
better adapted to pass as the German who, they had been informed by
Roy Stone, spoke Spanish only awkwardly.

"Buenos dios, Senor," said Jack, bowing gracefully.

"Ach du lieber Augustine," answered Bob, standing at salute.

They burst into hearty laughter, in which they were joined by Frank
and Roy Stone, who were present at the transformation.

"How will we do?" asked Jack.

Stone eyed them critically.

"To fellows that know Morales and Von Arnheim only by sight," he said,
"you will pass for them easily enough. Both of them are smooth-shaven,
which is unusual, for Mexicans and Germans both favor mustaches. But
that's all the better for you boys.

"One thing you want to remember," he said to Bob, "and that is to walk
pretty stiffly like you had a bone in your leg an' swallowed a ramrod.
That's the way Von Arnheim always steps out, An' both of you keep your
hats pulled down."

"Now you boys have got the bearings I gave you. You can easy enough
find the landing field, even in the darkness. It's a big meadow as
flat as a table, with the ranch house and outbuildings in a clump at
one end, an' the radio station with its big tower supporting the
antenna at t'other. Both places will be all lighted up, for Calomares
lives like one o' them old-time barons an' he's always got so many
men around the place he needn't fear nobody, so why put out lights?
He likes light. He's a bug on it, in fact."

"Suits me," said Bob. "That gives me some beacons to go by."

From the foregoing it will be seen that the boys had changed
materially their original plan of riding in as adventure-seeking
American youths to enlist in the rebel forces, and wait their chance
to effect the rescue of Mr. Hampton. As matters now stood. Bob and
Jack were to land in the airplane, and while Bob stayed by it, Jack
was to make his way to the room where his father was held prisoner,
free him, and guide him back to the airplane, when they would fly for
the border.

Of course, the plan would not be so easy of execution as it sounded.
To find the ranch and make a safe landing would be a fairly easy task.
The ranch was not more than fifty miles distant by air line, and in
that sparsely habited country there would be no other similar group of
lights to puzzle Bob. Once they had alighted, however, the
difficulties would be encountered.

At first the boys had considered the advisability of waiting until a
late hour to make their attempt. Rebel headquarters then would have
retired for the night, and they would run less danger of encountering
anybody on landing. In that event, however, they soon realized, ranch
and radio station alike would be dark and Bob would have no beacons to
guide him to a landing.

No, there was only one thing to do, and that was to arrive at an early
hour. Moreover, there would be this advantage attached, namely, that
sentries would be lax and that, with many persons coming and going in
and about the ranch, the passage of a familiar figure, such as they
would take Jack to be, would arouse no comment. Jack might be halted,
of course, by some one desirous of conversation. But he could make
some excuse to pass on. As a matter of fact he planned to wrap a
handkerchief about his jaw and pretend to be suffering from toothache.
This would serve the double purpose of partially hiding his features,
and of excusing him from indulging in extended speech.

"All right," said Jack, finally, as he finished donning his disguise
by clapping Morales' hat on his head. "Let's go."

"Ya, ya," said Bob, doing a goosestep. Once more they all had a good
laugh. Then Bob and Jack walked into the outer room of the cave,
followed by Frank and Roy Stone. Stone had thrown caution to the
winds, and had decided not to try any longer to hide his defection
from Morales and Von Arnheim.

"I'll soon be riding away from here with you, anyhow," he told Frank.
"And they'll find out then, if they haven't already suspected. I'm
going down to the airplane to see the kids off."

Frank had demanded this privilege of going down to the valley and
seeing Bob and Jack get away, and the others had no thought of denying
him. So all four, bearing the oil torches kept in the cave by Stone
for the purpose of lighting the landing field at night, descended from
the cave. Tom Bodine was left to guard the two prisoners.

These had again suffered the ignominy of having their hands tied,
after they had undressed, and, wrapped in the rubber ponchos given
them by Bob, they had flung themselves down on the pallet prepared the
previous night by the boys.

Stationed in the outer entrance of the cave, Tom Bodine looked around
at the two prone forms several times. But always they lay motionless
under their ponchos, and there seemed no cause for suspicion regarding
them. Poor fellows, thought Tom, who held no particular animosity
against them, they had had a hard time of it lately. After landing
from a flying trip, they had been set upon and beaten. Then, made
prisoner, they had spent the intervening hours cramped in bonds and in
doubt as to what their captors intended doing with them. Probably were
tired out and asleep by now, thought Tom. He even tiptoed over to
where they lay and found, as he had expected, that both had their eyes
closed and were breathing heavily.

Returning to the entrance, Tom took a step or two forward so as the
better to see past the big rock outside and thus get a clearer view of
the airplane. The boys had reached it by now, the oil flares were
planted to both sides, and it was illuminated, standing out in the
tossing light like a great bird.

As the propeller began to whirl, Tom took another step or two forward.
An airplane was a new puzzle to him, and he was so interested in
watching it get under way that he forgot his trust, forgot he had
prisoners to watch, forgot everything but the mystery of that piece of
mechanism, that gigantic bird, running bumpily now over the ground and
now beginning to lift into the air, and now----

Tom whirled about. The old instinct of the man who lives much in the
open, telling him danger is close at hand, was stirring at the roots
of his hair. But he was just a trifle too late. As he faced about, a
form shot out of the cave and Tom, totally unprepared for attack, was
bowled over.

As he fell he let out a great wordless cry, thinking to warn Frank and
Roy Stone. Then the butt of a revolver descended on his head.




CHAPTER XXIII

THE TABLES TURNED


"What was that?" asked Frank, turning to Roy Stone, as the airplane
bearing Jack and Bob on their romantic adventure dwindled in the
darkening sky. "I thought I heard a shout."

"Guess you did," said Stone. "I heard it, too. It came from the cave."

Both turned to stare upward toward the distant cave. There was no sign
of movement. Only the dim bulk of the rock obscuring the entrance
could be distinguished. They looked at each other, a nameless fear
stirring at their hearts. Then Frank shook himself and laughed.

"Pshaw," said he, "this lonesome place seems spooky. I know what it
must have been. It must have been Tom shouting a farewell to the
fellows."

"Reckon you're right," said Stone, brightening. "Sure, that must be
it. Well, let's go back. We'll be starting in a couple of hours, if
all goes well."

"All right," said Frank, reaching to pluck one of the oil flares out
of the ground.

Stone halted him. Again he looked anxiously toward the cave.

"Let's not take the torches," said he.

"Why not?"

"Just playing a hunch," said Stone. "I have the feeling that all may
not be well up at the cave."

Frank dropped his voice unconsciously, as if fearing eavesdroppers in
that lonely spot.

"To tell you the truth," said he frankly. "I feel the same way. I say!
I have an idea. Let's edge out of the light without hurry, not toward
the cave, but out that way," pointing in the direction taken by the
airplane. "We'll put our hands up to our eyes and pretend to be
watching the sky for the airplane's flight. It would be natural for us
to want to get beyond the light of these torches, if we were trying to
follow the boys with our eyes."

"That's the ticket," said Stone, and the two put Frank's plan into
execution.

Beyond the light cast by the torches they paused. Darkness had
descended now, in truth. Not even the shadowy bulk of the big rock
before the entrance to the cave could be distinguished.

"Maybe we're making ourselves nervous over nothing," said Stone. "I
feel kind of foolish. After all, what could happen? That old cowman
pal of yours looks pretty capable."

"He is, too," said Frank. "Just the same, I feel we ought to be
cautious. If Tom's all right when we reach the cave, well and good.
But if he isn't------"

"You're right, kid," said Stone. "I'm no more of a coward than the
next fellow. But if Morales and Von Arnheim by any chance gained the
upper hand and got their clutches on me, I'd hear the birdies sing."

Frank had been thinking rapidly.

"Look here," he said, "isn't there some way we can sneak up there to
find out if matters are all right or not? Suppose Tom has been
overcome. We wouldn't stand much chance approaching the cave by the
regular entrance." He paused and again stared upward. "We've been gone
a considerable time," he said nervously. "You'd think if he were all
right, Tom would have called to find out what is delaying us."

"Tell you what," said Stone, "I've got a little private path to the
top of the cave where the antenna is located. It isn't much more than
a goat track. But we'll have to be goats. Never been up it in the
dark, but I think I can make it. Are you game to follow me?"

"Certainly," said Frank, "if it will be of any advantage for us to do
so."

"Well, there's a fissure through the rock down into the cave. That's
where the Germans that put in the radio plant made their hook-up. We
can listen there, and maybe hear something to guide us."

"Oh, I remember that," said Frank, and added excitedly: "Maybe I could
crawl down into the cave."

"You might be able to, at that," said Stone. "You're pretty slight.
But it would be a ticklish proposition without any rope from above.
Well, if you're on, let's go."

Turning he struck off across the valley, approaching the hill some
distance from the path leading to the cave. Frank followed closely at
his heels. Soon they began mounting upward. The climb in the darkness
became more and more difficult, made more so by the care they
exercised to prevent dislodging stones. They feared the clatter of
these descending to the bottom would betray them.

Once Stone, who was in the lead, slipped and slid backward, clutching
frantically to stay his fall. Fortunately, Frank was well braced at
the moment and was able to stop him. After a rest to regain their
breath and calm their shaking nerves, they resumed the climb.

At length Frank's feet were on level ground and ahead he saw the
outlines of two latticed towers of familiar construction, and between
them overheard the strands of the antenna. The Germans, Stone earlier
had explained, had built the towers in such fashion that the crest of
the hill hid them from the plain on one side while they were so far
back from the edge of the flat plateau crowning the hill as to be also
hidden from view from the valley.

Whispering an injunction to Frank to follow close at his heels, Stone
crawled on hands and knees to the fissure in the rocks down which led
the wires of the hook-up. It was not a straight descent into the cave,
and no light came from it. But the two knelt in the darkness and put
their heads close to the black opening to listen.

A murmur of speech could be heard distinctly, coming up through the
hole. Frank could not distinguish the words, but with his limited
knowledge of Spanish he was able to decipher that language was being
employed.

"What is it?" he whispered to Stone. "Can you hear? Are they speaking
in Spanish?"

"Silence. Just a minute," answered Stone.

His voice was anxious. Frank obeyed the command. In a moment, Stone
lifted his head and said hoarsely:

"It's Morales. He and the German must have overcome your friend in
some way. And I think he's got the Calomares ranch on the phone and is
giving warning that your friends are on the way."

Frank groaned.

"Then when Jack and Bob land, they'll be surprised and captured. Oh,
can't we do something?" Excitedly he jumped to his feet. "Let's put
the radio out of commission."

Stone also leaped up and laid a restraining hand on his arm.

"No, no. Wait a minute. The damage is done already. These fellows
already have given sufficient warning to put them on guard at the
ranch, even though they can't have told the whole story."

They stood undecided, looking at each other, in the starlit darkness.
With an exclamation, Frank seized Stone by the arm. In his excitement,
he shook it.

"Jack and Bob both clamped the headpieces on when they left in the
airplane," he said. "And Jack tuned the radio to the pitch of this
station, in order to be able to call us after rescuing his father.
Why, he must have heard Morales give his warning! Yes, sirree. Why
this isn't so bad!"

In their relief, the two laughed a trifle hysterically. In a moment,
however, Frank sobered again.

"Just the same," he said, "the ranch would get the warning, unless--"

"Unless what?"

"Unless Jack was quick enough to grasp the situation."

Stone slapped his leg.

"I see what you mean," he said. "Your friend Jack could call the
ranch, too, and interfere so much that Morales' message would be all
twisted up."

"That's it," said Frank. "And when it comes to thinking quickly and
acting at once, you can count on Jack. Just the same," he added, "he
can't keep that up forever, and when he lands--"

"Which he'll have to do shortly," interrupted Stone, "because the ranch
is only fifty miles from here."

"Why, then," continued Frank, "these fellows can get their warning to
the ranch and the boys will be captured, or at least their plan to
rescue Mr. Hampton will be spoiled. No, sir, we'll have to wreck the
radio plant here to give them a chance. If Jack has been able so far
to interfere with the warning, and we put this plant out of commission
now, they may be able to carry out their rescue after all. Let's see.
How will we go about it?"

Both had been so engrossed they had failed to notice a dark form
which, after creeping noiselessly up the slope, had started edging
across the little plateau. Now this form suddenly straightened up and
leaped forward. Frank cried out in alarm and jumped sideways, just as
a spurt of flame split the darkness. The bullet sped by, leaving him
unharmed. Stone, who was closer and stood with back turned, whirled
about. The charging form cannoned into him, and he went down.




CHAPTER XXIV

FRANK SAVES THE DAY


Frank's first thought was to go to the assistance of Roy Stone. The
latter and his opponent--in the darkness Frank could not distinguish
whether it was Morales or Von Arnheim--were locked with their arms
about each other and rolling on the ground. His second thought was as
to the whereabouts of the other man.

He glanced about in alarm. Dark though the plateau was, however, he
could see there was no other in sight. Bending down to the fissure in
the rock, he could still hear the voice of Morales, and although he
could not distinguish the words, he received the impression that the
Mexican was angered for some reason. To Frank this meant that Morales
was having difficulty in radioing the Calomares ranch, and his heart
leaped with exultation. Jack had interfered.

A wild thought leaped full grown into his mind. Stone had given Bob a
stiff battle; he probably would do the same to Von Arnheim, even
though his shoulder was sore. What was to prevent Frank from slipping
down to the cave while the two were engaged, where he could release
Tom Bodine, surprise Morales and recapture the cave and the radio
plant?

The next moment a feeling of shame surged over him. If Von Arnheim
gained the upper hand, he would kill Stone without compunction.
Putting aside his first thought, Frank ran to where the two forms
still lay tightly locked on the ground, neither able to gain an
advantage.

He bent down, and the first thing his gaze encountered was an upflung
hand grasping a revolver, and another hand gripped about the wrist of
the first and preventing use of the weapon. He surmised it was Von
Arnheim who held the weapon, and acted accordingly.

Grasping the German's hand, he pressed back the fingers so sharply a
cry of pain was wrung from Von Arnheim's lip. The revolver dropped to
the ground. Its owner, however, pluckily continued the fight. Frank
danced about, the captured weapon clubbed in his hand, ready to deal a
blow when possible. But so furious was the fight that he feared to
strike, lest he hit his friend.

Precious minutes were flying by. He was in an agony. Morales had to be
prevented from radioing the ranch, if Jack and Bob were to stand their
chance.

Then suddenly Roy Stone gained the upper hand of his opponent. He
legs were twined about Von Arnheim, he clutched the other to his
chest, one arm was in the small of his back, the other was pressed
across his throat, his chin was sunk deep into the German's shoulder.
Von Arnheim had only one arm free, the other was pinioned to his side.
With this free arm he plucked futilely at Roy's arm across his throat,
unable to reach the guarded face. It was a grip Von Arnheim was
powerless to break, and it was only a question of time until he would
be throttled into submission.

With a leap of the heart, Frank realized this. And bending down with
his lips to Stone's ear, he said:

"I've got his gun. If you can hold him now I'm going into the cave
after Morales. He's still at the phone."

A grunt was Stone's only reply as he pressed his chin deeper into the
other's shoulder. Von Arnheim's body was beginning to arch like a bow.
If he did not surrender soon, his back would be broken.

Frank darted off down the slope.

Morales was seated at the telephone as Frank entered the cave,
captured revolver in his hand. His own weapon hung forgotten at his
side, so little used was he to the handling of small arms. Frank had
tumbled, fallen, rolled down the slope, taking no precautions, fired
only with anxiety to prevent Morales from radioing while there was yet
time.

The Mexican also, in his anxiety to reach the ranch and give the
warning, had cast caution aside.

Across the outer room dashed Frank, scarcely noting the trussed-up
figure of Tom Bodine flung in one corner. No hangings obscured the
brightly-lighted interior of the inner cave, for they had been torn
down the night before to form a pallet.

Morales sat with his back turned, the headpiece clamped over his ears.

Frank darted forward and brought the butt of the revolver crashing
down on the Mexican's head. Without a sound, without a gurgle or a
cry, Morales swayed in the chair, then slumped to one side and slid to
the floor.

With nervous haste Frank pulled the headpiece from the other and
clamped it on his head. At once a crackle of Spanish words filled his
ears. He could make nothing of them. What little knowledge of Spanish
he once had possessed was not at his command now.

"Jack, Bob," he cried, pulling the microphone toward him. "This is
Frank. Do you hear me? Frank."

The chattering ceased as if by magic.

"Frank? What in the world?"

Glory be! It was Jack's voice in reply.

"Use the code," cried Frank. In this emergency his brain was working
lightning-fast. And in their own private code he added:

"It's all right now. They captured Tom Bodine while we were down in
the valley seeing you off. But we've recaptured the cave."

"You saved our lives," came back Jack's voice. "I heard your Mexican
friend call the ranch while we were flying, and at once started to
interfere. It's been a job and my throat's hoarse. But he never got
his message through, I can tell you that. Whatever it was he had to
tell, I never did find out. I just started interfering, singing,
talking, shouting. The ranch never found out what he was trying to
say, and neither did I. But, boy, you're just in time. We can see the
lights now. What? What's that?"

What he heard was a shout.

But Frank was too busy to answer his question. Morales had recovered
consciousness and was on his knees and struggling to his feet, when
out of the tail of his eye Frank saw his peril. Snatching the
instrument from his head, he flung himself sideways. The impact of his
body hurled Morales again to the floor.

Frank had placed the captured revolver on the table, as he telephoned.
He would have to fight with his bare hands. Well, he would not let the
Mexican overcome him and regain possession of that radiophone unless
he killed Frank first. With hands gripped about the other's throat and
legs twined about his body, Frank fought as he never thought he could
fight. Morales was a heavy man, heavier even than Von Arnheim who had
overcome Frank in that tempestuous fight in the darkness the night
before. But his senses were still somewhat numbed from the blow on the
head dealt him earlier by Frank, and the boy was fighting with a
strength born of desperate resolve.

Frank's grip on the Mexican's throat tightened. Morales was unable to
pluck those cruel hands away. His face became purple. His eyes started
from his head. Suddenly he went limp beneath Frank, and sank to the
floor.

Frank stood up swaying. The excitement and the strain of the combat
had had their effect on him. There are mighty few boys of his age and
build who could have gone through what he did and still keep their
feet. Dancing points of light swam before his vision. He brushed a
hand across his eyes to clear them. He reeled and would have fallen,
but his hand clutched the table and steadied him.

What was it he must do? There was something which had to be done. Oh,
if his head only would clear. Call Jack! Yes, that was it. Had to tell
the old boy to go ahead--radio plant still Frank's--enemy couldn't
get any warning from that Mexican fellow--had to tell him, had to.

Clutching the table, swaying, but with lips tightly pressed together
and teeth clenched, Frank made his way to the microphone. Holding the
headpiece to his ear, he set his lips to the telephone instrument and
called:

"Jack, Jack, you there?"

"Yes, yes," came back the anxious reply. "What happened?"

"It's all right, Jack. Go ahead. I licked--him."

The headpiece fell from his grasp. Frank sank to the floor.

It was there a moment later that Roy Stone found him, fallen in a heap
across the body of the Mexican. Both were unconscious.

Stone was shaky himself. His battle with Von Arnheim had been a severe
one, and the wound in his shoulder had started bleeding again. But as
his gaze took in the situation, he turned to Tom Bodine, whose bonds
he had cut on his way through the outer cave, and said in a tone of
warmest admiration:

"Some boy."




CHAPTER XXV

DANGER AT HAND


Bob as well as Jack had heard Frank's explanation of the occurrences
at the cave, for he also wore a headpiece as he piloted the airplane.
And it was with warm admiration toward the absent chum who so
heroically had thwarted Morales' attempt to betray their hazardous
expedition that he circled now above the two groups of lights which
marked the Calomares ranch and radio station.

Smaller and smaller grew the circles, as with engine shut off he
volplaned. The field was hard-packed and smooth and the plane alighted
finally with practically no jar. When it came to a dead stop at last,
Bob drew a long breath of relief. He had not been up for several
weeks. And night flying above strange country to a landing on
unfamiliar ground had been a strain upon him.

There were no mechanics running out to greet the alighting plane and
trundle it into its hangar. Had this been a well-appointed landing
field, such absence would have been suspicious. But to Bob and Jack it
meant only confirmation of Roy Stone's remark that they were a
"careless lot at the ranch."

"Now for it," said Jack, clambering out of the plane.

The two chums stared around them, trying to pierce the darkness. They
were in the middle of a long and wide field. A ring of low hills
encircled them, the tops clearly outlined against the velvety sky.
Overhead twinkled stars, brighter, warmer and apparently closer than
when viewed in their Long Island home.

The hills on either hand were close. So, too, was the rampart at their
back, over which they had flown. Those ahead were more distant, for it
was in that direction extended the valley. Behind them was the radio
plant with its tracery of tower and antenna against the sky and the
windows of the power house gleaming from the light within. Ahead was a
long, irregular clump of buildings set among trees. Some were dark.
But the main structure, which they knew from Stone's description was
the ranch house, was brightly lighted.

Try as they would to pierce the darkness, the boys were unable to
discern anything other than this. There was not a human figure in
sight.

They gazed with especial interest toward the ranch house, because it
was somewhere within those walls that Mr. Hampton was held prisoner.
Soon, if all went well, Jack would be making his way within in search
of his father. At the thought, his heart which heretofore had been
calm enough, began to beat rapidly and for a moment he felt as if he
were about to suffocate. His breath almost failed him. It was a not
unnatural feeling, and soon passed, but Bob noting the labored
breathing climbed from the airplane and put an arm over his chum's
shoulder.

"Steady, Jack," he said. "Everything's going to be all right."

The friendly gesture and the sympathy in his chum's voice did steady
Jack.

"All right, now, Bob," he said. "Just at first, though----"

"Righto," the big fellow answered. "I'm scared stiff myself, and I'm
not even going into the ranch. If I were in your boots I'd probably be
shaking myself loose from them."

The pleasantry was what Jack needed. He grinned at the thought of big
Bob shaking so much with fear as to shake off his shoes, and his
recovery was complete.

The plan was for Jack, in the dress and character of Morales, to go to
the ranch house, enter boldly and make his way to the room where his
father was held prisoner. Bob was to stay with the plane. Releasing
his father, Jack would return with him. Then they would all three fly
away across the international boundary to the north.

It was impossible to foretell, of course, what obstacles to the
carrying out of this daring proposal would arise. Both boys felt
certain, however, that so far they were not suspected, and that first
Jack and then Frank had successfully thwarted the attempt of Morales
to send a warning to the ranch by radio.

Neither was aware, of course, that the jumble of sounds through the
air, when Jack from the airplane had interfered with Morales' attempt
to warn the ranch, and later the code conversation between Jack and
Frank, after the latter had obtained possession of the radio plant in
the cave and had overcome Morales, had aroused the curiosity and then
the suspicions of the young German, Muller, who operated the radio
plant at the Calomares ranch.

A few moments before the beat of its engine in the sky signalized the
approach of the airplane, Muller had decided to go to the ranch and
report to Calomares. He had crossed the landing field afoot and had
just reached the belt of trees when the machine volplaned to the field
behind him.

Although, as has been said, his suspicions were aroused, Muller was
far from suspecting the truth. He had no idea the airplane had been
recovered by its rightful owners and that these latter were about to
make a daring attempt to rescue Mr. Hampton. His thought on the
contrary, was that something--he could not make a more definite
surmise--had gone wrong at the cave.

Therefore, when, after standing several minutes at the belt of trees,
gazing back toward the airplane, he saw a figure start from it for the
ranch house, he believed it was either Von Arnheim or Morales coming
to report.

Muller was a sycophant, the type of man eager to curry favor with
those in authority. He decided he would gain the ear of the great
Calomares first. That would detract somewhat from the glory of the
other when he arrived. Turning he darted for the ranch.

Meantime, Jack was making his way ahead more slowly. While not
attempting to hide, he was on unfamiliar ground and felt that it
behooved him to follow implicitly the directions given by Roy Stone
and make no mistakes.

Passing through the grove, Jack came in sight of the ranch. He paused
in astonishment. Roy Stone's description of the great house had
prepared him in a measure. Yet he was astounded. Here, indeed, was a
palace in the wilderness.

The mansion stood on a slight elevation with a lawn in front sloping
down to the trees from which Jack had emerged. In design it was like a
country house of the ancient Roman aristocracy. The walls were of
vari-colored brick with inlaid designs representing formal flowers.
Two stories in height, with towers at the corners rising another two
stories higher, the building was in two wings or sections, joined in
front by a marble-tiled walk, roofed and pillared, but with the sides
open. Inside, between these two wings, Roy Stone had told Jack, was an
open court.

Nerving himself to the ordeal, and pulling down his hat to obscure his
features, Jack crossed the lawn and started mounting the wide flight
of stone steps flanked by crouching stone lions. He reached the marble
tiles of the walk above and then, despite his anxiety to gain the left
wing and the tower where his father was confined, he involuntarily
paused.

The scene before him was one of the strangest to be found on the North
American continent--this marble courtyard, with its overhanging
balcony around the sides and rear and its splashing fountain and pool
in the center, the whole illuminated by the soft glow of electric
lights cunningly concealed along the edges of the balcony like
footlights on the lip of a stage.

But it was not this alone which held Jack's gaze riveted and caused a
smothered cry of surprise to burst from his lips. Involuntarily he
stepped from the shelter of a pillar behind which he had been
standing.

For approaching along the balcony of the left wing, Jack saw the
loved figure of his father engrossed in conversation with a small,
dark man of patrician bearing.

It was instinct rather than conscious thought which checked the cry on
his lips. Instinct told him a shout would mean betrayal, and the
shattering of his desperate plan.

Yet careless of who might see, he stood there looking up at the
distant figure until it was lost to view, cut off by the outjutting
roof above him. That one sight, however, lifted a vast load from the
boy's mind. His father, at least, was not mistreated. Evidently the
man with him was the Don. And as evidently his father was treated more
as guest than prisoner.

At sound of a footstep on the marble tiles behind him, Jack returned
with a start to a realization of his surroundings and the perils of
his position. Assuming a carelessness which he was far from feeling,
he refrained from turning about but instead started walking for that
left wing ahead in the tower of which he knew his father to be lodged.

But the step behind him was accelerated, and he was hailed by name as
Morales. Jack halted. Here was the first ordeal to be passed. Well, he
was prepared for it. According to his plan, he had bound his face in a
handkerchief and intended to pretend having the toothache. The
swathings partly hid his features, and the pulled-down hat further
obscured them.

"I'm busy. Don't delay me," he growled in Spanish, imitating Morales'
voice.

The newcomer approached. It was Muller.




CHAPTER XXVI

THE NIGHT ATTACK


When Jack's figure had become merged in the shadows of the grove, big
Bob, standing beside the airplane, reached a decision.

"Not a soul in sight here," he muttered to himself, once more letting
his gaze rove over his surroundings. "Jack thought it would be best
for me to stay here, but nobody's going to monkey with the plane. I'm
going to follow him--till he reaches the house, anyhow. He may need my
help."

Thus the big fellow salved his conscience for departing from orders.
But he was so eager to take a hand in proceedings that he felt it
would be torture to stay behind. He was dressed in Von Arnheim's
clothes. And his build was that of the German aviator. If he were
observed, he would not be suspected. Even his atrocious Spanish would
not betray him, as the German spoke the language almost as horribly as
he.

Thus he reasoned to himself, as he strode rapidly after Jack.

When he reached the other side of the grove, and came in sight of the
ranch house Bob, as Jack had done, halted in amazement at sight of the
splendid structure.

He gazed around him. Nobody in sight. Shrubbery intervening prevented
him from gaining a clear view of the house. He started to skirt the
bushes.

Meantime, not far away, the conversation between Jack and Muller was
nearing a climax. Approaching the pretended Morales, Muller asked what
he had tried to convey in his radio call, explaining it had been so
interfered with by another mysterious call as to be non-understandable.
Not knowing Muller was the radio man at the ranch, Jack was nonplussed.
Again he answered that he could not be delayed, and started to withdraw.
Then Muller laid a detaining hand on his arm.

"Keep it to yourself, if you want to," Muller said. "But I know
something happened at the cave and I have already reported so to the
Don. First I thought you were trying to radio from the cave. Now here
you come by airplane. There's--"

"What do you mean?" growled Jack gruffly, although secretly alarmed.

"I mean there's something wrong," Muller said.

Muller still had no suspicion that the man before him was other than
he pretended to be. Merely he was trying to pry into a matter that had
aroused his curiosity. Jack, however, thought he was on the eve of
being discovered, and was alarmed.

At this moment Bob, skirting a clump of bushes on the lawn below, came
in sight of the two figures and halted.

He saw Jack wrench his arm from the other's grasp and turn to stride
away. He saw the other raise an arm as if to stay Jack. And he saw the
movement flip Jack's low-pulled hat from his head. It was accidental,
but to Jack and Bob--the actor and the observer in this little
drama--it seemed to be by intent. It is possible Jack still might have
saved the day, had he stooped quickly, recovered his hat and clapped
it on again before Muller could have seen his features.

As it was, however, Jack thought he was discovered. And he turned to
deal with Muller. Then, in truth, he _was_ discovered. Muller cried
out in amazement. Then Jack landed a stinging blow on the mouth which
sent the young German toppling to the marble pave.

At Muller's shout, several rebel sentries, who had been snoozing in
the shadows beside the palace, instead of mounting guard, were
startled into instant wakefulness. They came trotting in bare feet,
long rifles in hand, and ran up the wide flight of steps.

Bob started forward to help Jack. The latter, however, took one look
at the sentries and then dashed into the left wing of the building.

The sentries for a moment did not pursue, believing the fleeing man
was Morales. Instead, they bent above Muller and helped him to his
feet. Bob halted, and backed into the bushes, keeping his eyes on the
scene. No use rushing in to help Jack now. He would merely succeed in
getting into trouble himself, without aiding his chum.

From his vantage point he was able to read aright what followed.
Although he could not overhear what was being said and would not have
understood the Spanish words, if he had overheard, nevertheless he
gathered that Muller was explaining the fugitive was not Morales, but
someone wearing his clothes.

Then he saw the sentries dart away in pursuit of Jack, while Muller
whipped out a revolver and fired three shots into the air.

"That's an alarm," Bob said to himself. "I'd better back off before
this place is alive with soldiers."

Turning, he ran through the trees. Big Bob was not the one to desert a
friend, but he saw no chance to help Jack now. On the other hand, he
told himself, if he retained his freedom, he would be able to help
Jack later perhaps.

Suddenly he carromed into a man running toward the house. Both
rebounded from the contact. Bob saw the other was a Mexican with a
rifle. Quick as thought, he lashed out with his right fist and caught
the soldier on the point of the jaw. Totally unprepared for this
attack, the man went down as if shot.

Bob ran on at redoubled speed, burst through the screen of trees, and
dashed across the landing field toward his airplane. He had no
definite idea as to what course to pursue. He and Jack, of course, had
counted upon the possibility of Jack's being discovered. In that case,
when he heard the alarm, Bob--supposedly sticking by his airplane--was
to have flown away.

There were shouts behind him. Evidently his soldier victim had
recovered. Perhaps, even, Muller had suspected the truth, namely, that
if Jack were not Morales the aviator who had brought him was not Von
Arnheim. In that case, Muller would be on his trail and he would have
no time to lose.

What should he do?

The shouts behind him were not repeated. Perhaps, after all, his
identity was not yet suspected and he was not pursued. Jack might be
keeping all hands busy at the ranch.

In great leaps, he approached the airplane and, as he drew near,
another thought obtruded itself. If he were to take flight in it, how
was he to get away? Who would crank the motor by twirling the
propeller?

This latter difficulty was quickly solved. Two Mexicans stood at
respectful attention as he approached. Bob was dismayed for a moment,
but then, seeing their awkward salute, he chuckled inwardly. They
mistook him for Von Arnheim and evidently that German officer was a
martinet who exacted a measure of discipline from the slovenly rebel
soldiers.

Cracking an order at them in his best garbled Spanish, Bob clambered
into the pilot's seat. He was understood, and better, was obeyed. One
man gingerly approached the propeller and started twirling it, while
the other went to the side of the plane and helped push it forward.

The propeller began to whirl furiously as Bob worked the starting
mechanism. The Mexicans leaped out of the way. The plane began to bump
ahead.

Shouts of anger burst forth at the same moment, there was the crack of
a rifle, and a bullet sang unpleasantly close to Bob's ears. Out of
the tail of his eye he could see a number of dark figures running
toward him from the grove.

But Bob did not wait to be interviewed. With a swoop, the airplane
left the ground and started upward. His pursuers were so close at hand
they could almost grasp the wheels, as they leaped upward. Yet not
quite. Bullets whistled about him, and several pinged against the
body of the machine with a sharp metallic ring. Bob thanked his stars
that the plane had an all-metal body. Once above pursuit, he was safe
from stray rifle shots.

With a curse the baffled Muller, who had been quick to realize that if
one masquerader was not Morales, then the other was not Von Arnheim,
watched the airplane shoot away at dizzying speed and disappear beyond
the guarding hills to the north.

Then he turned back toward the ranch house, eager to learn how the
pursuit of Jack had ended.

But for young Herr Muller and the Calomares ranch in general the night
alarms were not ended. In fact, they had just begun.

Before Muller on his return trip had reached the belt of trees, while
the search for Jack, who had mysteriously disappeared, went on merrily
within the Calomares palace, and while Bob was yet flying over the
hills to the north, rebel pickets below him were attacked by Mexican
government troops.

It was an attack in force.

"Viva, Obregon," shouted the attackers.

The rebels on the northern rampart of hills defending the natural
amphitheatre where the Calomares ranch was located, fell back
hurriedly. They were outnumbered.

Out of the huddled buildings, which the boys had only glimpsed at the
rear of the great ranch house boiled scores of rebel soldiery,
rubbing the sleep from their eyes, hugging their rifles as they
trotted forward in bare feet. Within the house, the search for Jack
was temporarily abandoned, while the peppery little Don Fernandez
Calomares, alarmed at this night attack which might mean that the
government troops were in force, hastened to take command outdoors.

To Bob, who having crossed the crest of the hill had shut off his
motor and volplaning, the shots and cries of the attackers came
distinctly. He had intended making a hazardous landing beyond the
rebel lines and returning afoot to try and rescue Jack. But this
newest development in the situation caused him to open the motor and
start to spiralling upward.




CHAPTER XXVII

SENORITA RAFAELA


Meantime, what of Jack.

After bowling Muller over and fleeing from the sentries drawn by the
latter's shout, Jack ran through the great arched doorway into the
left wing of the palace. Ahead lay a dark corridor, upon which opened
the doors of the ground floor rooms. He was in a round entranceway
from which ascended a flight of winding stone steps to the balconied
upper floor and the turret rooms above. Up there, somewhere, was his
father. Jack paused only a moment, then sprang up the steps.

As he reached the upper landing, he heard the sound of footsteps
descending from the tower. He listened a moment. They were not the
familiar footsteps of his father.

He must act quickly, if he were to stand any chance of escape.
Springing forward, revolver in hand, he seized the knob of the nearest
door on the balcony, found the door give and leaped in, pushing it to
behind him and setting his back against it.

The room was brightly lighted, evidently a young lady's boudoir. This
much his first glance showed Jack. It showed him also two women--one
young and very beautiful, the other wizened and monkey-like, both
terrified and speechless. They were Don Fernandez' daughter, Rafaela,
and her duenna or chaperone, Donna Ana.

"Quiet," hissed Jack in Spanish, waving his weapon threateningly.

He listened with strained attention to sounds from outside. The
menacing footsteps reached the landing, and then continued to descend.
Jack turned the key in the lock. He was none too soon. A moment later
the padding of the bare feet of the sentries sounded muffled outside,
then grew fainter as the men separated, one ascending the stairway of
the tower, the other running along the balcony.

Jack was puzzled as to what next to do. From Roy Stone's brief
description of the Don's family, he guessed at the identities of the
two women. While he stood irresolute, the girl recovered from her
fright. Her dark eyes flashed, and she commanded him in an imperious
tone to lower his weapon.

"Not till you promise me not to shout, Miss," Jack said.

"Very well," said the girl. "But who are you? You cannot escape. My
father will capture you."

"Not if I can help it, Miss," said Jack grimly.

In the rapid march of events, the handkerchief with which he had
bound up his jaw had become loosened. Now it fell, revealing Jack's
handsome features and his close-clinging mop of dark curls.

"Why, you are just a boy," declared Rafaela, and her eyes lost some of
their hostility while at the same time, unconsciously, her voice
became less harsh.

"Surely," she said, turning to Donna Ana, "this lad can have done
nothing so terrible."

The prim, black-robed duenna had gained courage from her mistress's
temerity. She had ceased trembling. Yet she was exercised about
something. Jack could not understand why. Surely, she was no longer
fearful of him. She leaned closer to her young mistress, seated at a
low writing table, and whispered in her ear. Rafaela threw back her
head and laughed--a low, musical laugh that sounded fascinatingly
pleasant in Jack's ears, worried though he was.

"My dear Donna Ana," said the girl. "What if he is a man! And in my
room! Are you not here to watch over me? And I do not believe he will
bite. No, no. See, he is such a nice young man that I can chuck him
under the chin. So!"

And suiting action to words, the girl sprang from her chair, walked
swiftly across the room and chucked Jack under the chin.

To say that Jack was surprised would be a mild statement. From his
knowledge of Latin-American girls gathered in Peru, he believed those
of good family invariably were convent-bred and extremely decorous in
the presence of young men. He was so dazed at the girl's action that
her next move, which was a lightning-quick attempt to grasp his
revolver and wrest it from him, almost succeeded.

Jack retained a grip on the weapon, however, and managed to prevent
Rafaela from obtaining it. Foiled in her attempt, all her bravado
deserted her and running back to her chair, she sank into it and began
to weep.

What in the world should a fellow do in a case like this? Jack didn't
know. Usually, he was equal to emergencies, but this one was something
beyond his understanding. He stood helpless, while the duenna
alternately glared at him and patted her young charge on the back,
muttering soft words of comfort to her meanwhile.

Quickly as the shower came, however, it disappeared. Rafaela pushed
Donna Ana aside impatiently and looked at Jack, smiling through her
tears.

"Well, sir," she said, demurely, "that did not succeed. What do you
intend to do with your prisoners?"

This wasn't so bad. Jack grinned.

"Look here," he said, sensing a kindred spirit. "I'm not a rascal. You
will have to believe me. I haven't done anything so terrible, after
all. You need not be scared of me."

"But who are you, then?" asked the girl. "Listen. They are shouting
through the house. Soon they will be making a search from room to
room."

Jack started. If that were true, when the searchers came to this
locked door, what would happen? He thought for a moment. The daring
idea to take the girl into his confidence and enlist her aid had been
budding in his mind. He regarded her keenly for the first time. Would
she help? Perhaps the romantic nature of his enterprise would appeal
to her, even though he was fighting against her father. Well, it would
do no harm to try.

"You asked who I am," he said, "and why I am here. Well, I shall tell
you."

And speaking rapidly in his fluent Spanish, in a few brief statements,
he laid before her the main fact that Mr. Hampton, whom she doubtless
knew, was his father, and that he had come to the rescue in an
airplane.

"Only now," he concluded mournfully, "I have been discovered. I expect
my chum will be forced to fly away. And it looks as if I were bound to
fail."

During his recital, the girl's eyes had grown bright with interest.
She leaned forward, listening with eager attention. As Jack ceased,
apparently she was about to speak, but there came a tattoo of
knuckles on the door which caused her to halt abruptly.

"Our deliverers," murmured Donna Ana, who had never entirely ceased
trembling, and she cast a spiteful glance at Jack. To the duenna,
young men, and especially one so unceremonious, were terrible
creatures.

"Silence," hissed the girl, and the old duenna in evident fear of her
imperious young mistress, trembled the more.

"Quick," whispered Rafaela to Jack, "get under here."

Rising, she seized him by an arm and partly led, partly pushed him to
the chair upon which she had been sitting. It was a wicker chair, with
wicker-latticed sides extending clear to the floor. Lifting it, she
ordered Jack to kneel down and crouch into as small a space as
possible. He complied. Then she clapped the chair over him. He was
completely hidden, except in front, where the wicker latticing did not
extend.

Seating herself calmly in the chair, Rafaela so disposed her skirts
that Jack could not be seen. Then she picked up her pen and sat as if
just interrupted at her writing.

The knocking on the door was repeated, louder this time, and the
voice of the Don himself impatiently bade that the door be opened.

Bending low so that Jack could hear her words, the girl whispered:

"Have no fear. Trust me."

To the duenna, she said:

"Open the door. And if you betray me----"

And she shot at Donna Ana a terrible glance, which caused the latter
to cringe. Evidently, the duenna stood in considerable awe of her
temperamental young mistress.

The old woman unlocked the door and stepped back, revealing on the
threshold Don Fernandez with several armed retainers at his back.

"What does this mean?" he demanded, glaring at his daughter as he
advanced a step or two into the room. "Locked doors at so early an
hour?"

"Why, papa, dear, we heard the shouts and several revolver shots,"
said his daughter. "Was it not natural for two lone women to lock
their door?"

"Humm!"

The Don glanced quickly about the room.

"Papa, what is the matter? What is the meaning of all this noise? Of
those shots?" Rafaela anxiously inquired.

"Some man impersonating one of my lieutenants gained entrance," said
the Don. "I believe him a government agent. He may have come to
attempt my life."

"Oh, no, papa, dear," protested Rafaela, shocked. "Why, he--"

Frantic lest she might betray herself and him, Jack reached forward
cautiously and tapped the tiny ankle dangling before him.

He was none too soon. Thus brought to a realization of her position,
Rafaela checked the words.

"What's that?" asked her father. "What did you say?"

"Why, papa," she answered, "I was going to say he couldn't be so mean.
To come here to kill you. Oh, no. That would be too terrible."

"But I do believe it," affirmed the Don. "What do you know of how
politics is carried on in our poor, distracted country? Tut, tut, you
are just a girl. What I came to ask was whether the man had hidden
here? We have searched all the rooms on this balcony, without success.
Yet most certainly Pedro and Pancho"--indicating the armed men in the
corridor--"saw him bound up the stairs."

"Here?" said Rafaela. "Why, our door has been locked, as you see."

Before Don Fernandez could retort, the report of distant rifle fire
came to the ears of all in the room, followed by a growing fusillade
as the sentries on the northern rim of the valley fell back before
attack.

The Don whirled around.

"Hark," said he, and added with conviction: "The government troops are
attacking. And they sent an assassin ahead of them. Well, he has been
foiled. And they will be foiled, too."

And without more ado he darted from the room, Pancho and Pedro
obediently following at his heels.




CHAPTER XXVIII

THE FAIR TRAITRESS


Rafaela leaped up and lifted her chair, permitting Jack to emerge from
his unique hiding place. He was overcome with gratitude at the thought
of what she had done for him, and hesitated to speak.

"Speak," she said, frowning, and stamped her foot. "Tell me, is this
true?"

"What do you mean?" asked Jack in surprise.

"That you are an assassin sent by that horrible President Obregon?"

Jack was hurt, and showed his feelings.

"I told you the truth," he said.

"Oh, I want to believe you," cried the girl, twisting her hands. "But
father was so positive."

Donna Ana sidled close and whispered:

"Shall I call your father? It is not too late."

That decided Rafaela.

"Nonsense," she declared, sharply, glaring at her duenna. "Cannot you
see this young man is telling the truth? I," she declared proudly,
"can tell a truthful person from a liar at once. And I declare to you
this young man is truthful."

Jack smothered a smile. The girl was as changeable as a weathercock.
And calling him "young man" in that lofty tone, too. Why, she was
little more than a youngster herself--couldn't be as old as he.

"Come now," said the girl suddenly, seizing him by the hand. "We have
no time to lose. Now is your opportunity."

"Opportunity?"

"Yes, yes"--impatiently. "While the government troops attack, you must
release your father and escape."

Jack was amazed. Would this surprising girl never cease astonishing
him?

"Do you mean you will help me--actually?"

"Have I not said so?" asked Rafaela impatiently. "And it seems to me I
have already been of some trifling aid--actually?"

The sarcasm was not lost on Jack. But he ignored it. Finding he still
held the hand she had extended when urging him to follow her, he
squeezed it.

"You're--you're fine," he said, enthusiastically.

Rafaela tossed her head, smiling in superior fashion.

"You are not a very accomplished courtier, Mr. Jack Hampton," she
said, withdrawing her hand.

Jack would have protested. He was rapidly falling under the spell of
her charm. But she halted him with an imperious gesture.

"We are wasting precious time," she said. "Come." Then, turning to
Donna Ana, she said sharply: "You will stay here until I return. And
if you betray me--" Again she made a threatening gesture, and again
the old duenna cowered. Thereupon, the girl hastened from the room and
Jack followed.

Up the spiral stone stairway of the tower ran Rafaela, passing the
first landing where burned an electric light. Jack was close at her
heels. At length they reached the top landing, and stood before the
single door there. It was of stout oak, heavy and ponderous.

"This is your father's room," whispered Rafaela.

So near to a successful conclusion of his adventure, Jack's heart beat
so rapidly that once again he experienced that sensation of
suffocation which had seized him on landing from the airplane.

He tried the door knob. The barrier was locked.

"Locked," he whispered. "What shall we do?"

In the dim light on the landing, they stared at each other in dismay.
Here was a contingency which had occurred to neither.

The whispering, the careful trying of the door, the sound of their
footsteps--these had aroused Mr. Hampton from his reading on the other
side of the door.

"Who's there?" he called sharply.

Jack set his mouth close to the keyhole.

"Dad," he whispered tensely. "It's Jack. Don't make a noise. I've come
to rescue you."

There was a moment of silence, then the sound of rapid footsteps
crossing the room.

"Jack?" Mr. Hampton also had stooped to the keyhole. "It can't be. Yet
that voice! My boy, my boy. But how in the world did you come here?"

"Too long to tell, Dad," whispered Jack. "But have you the key to this
door?"

"Key? No."

"Then," said Jack, despairingly, "it looks as if we were balked at the
end. This door is too stout to break down without bringing the enemy
on us. It's thick and bound with iron straps besides."

"Who is with you?"

"Bob. No. I mean Miss Calomares. She's helping me."

"This is too much for me," declared Mr. Hampton.

"Dad, we'll have to break down the door. The government troops are
attacking. Even if we do make a lot of noise, it may go unnoticed.
Have you a heavy chair you can use?"

"Yes," answered his father. "But, wait. Government troops attacking,
hey? Then that is the meaning of those shots which caused Don
Fernandez to leave me so hurriedly."

"No, Dad, those first shots were when they sounded the alarm on
discovering me."

"They discovered you?" Mr. Hampton groaned in mock dismay. "Oh, this
is too much. But, Jack, what I started to say was that as Don
Fernandez dashed down the steps, I heard him drop something in his
haste that rang on the stones. Maybe that was the key."

"I'll look."

Jack stood upright, and communicated to the impatient Rafaela what his
father had said. She had been unable to hear. Fortunately, he carried
an electric torch. Swinging this so that the light fell on the steps,
he started downward. Before he had gone three steps, the girl's quick
eyes saw the key gleam in the light. She snatched it up with an
exclamation, turned, inserted it in the keyhole, and the door swung
in.

Jack leaped through the opening, and the tall and handsome man, to
whom he bore so striking a resemblance, enfolded him in his arms.

"My boy, my boy. I can hardly believe it."

"But it's true, Dad."

They drew apart and stood looking at each other. There was more than a
suspicion of moisture in each pair of eyes.

Mr. Hampton's gaze fell on Rafaela, with whom he had had a number of
pleasant conversations during his captivity. He dropped a hand on her
shoulder.

"My dear girl," he said. "You never did a kinder deed. I hope you will
not have cause to regret it."

"Oh," said she with an arch smile. "Papa would be furious if he
discovered what I have done. But I can manage him."

The older man smiled. He had observed the managerial process at work.

"But you must not delay," added Rafaela, anxiously. "Even now the
firing seems to be farther away. My father keeps many soldiers here.
And he is, doubtless, driving away the attacking party. You must go
quickly before he returns, and while all is confusion."

"She is right, Dad," said Jack. "Let's go. Anything you want to take
with you?"

"No, nothing. But how are we to escape, Jack? How did you arrive?"

"I arrived by airplane," said Jack. "But whether we can get away by
the same means is another matter."

Mr. Hampton looked dazed.

"The younger generation moves too fast for me," he said. "But will you
please explain?"

"It's a long story, Dad," said Jack, "and I haven't the time. But it's
Bob's airplane. The fellows who kidnapped you stole the machine in
Long Island several days before that. Well, Mr. Temple and the boys
came out to New Mexico, and we recovered the plane and, and--well,
there you are."

"Yes, I see," said Mr. Hampton. "It's as clear as a New York fog. But
it's enough to know that Bob--didn't you mention his name--is here
with the machine. Let's go and find him."

He started for the door. But at that moment Rafaela, who stood closer
to it, halted him with upraised hand.

"Listen," she whispered.

Cautious footsteps could be heard ascending the stairs.

"Quick, Jack," whispered Mr. Hampton, "you mustn't be seen. Nor you,
Miss Calomares. Here, hide behind this bed. And he pushed the two
behind the hangings of a great four-poster. Then removing the key from
the outside of the door, he hurriedly but noiselessly swung the
ponderous frame shut, and locked it on the inside.

"Calomares won't recall losing the key," he said grimly to himself.
"There may be a chance yet."

He listened with his ear at the keyhole. The cautious footsteps
mounted higher. They reached the landing. Then there was a low knock
on the panel, and a voice called low and urgently:

"Mr. Hampton. Mr. Hampton. This is Bob."




CHAPTER XXIX

THREE CHEERS FOR THE RADIO BOYS


Mr. Hampton unlocked and opened the door, and greeted the big fellow
as warmly as he had his own son.

"Where's Jack?" asked Bob. "Did they capture him?"

Jack, who was peeping from behind the four-poster, sprang into the
room, and slapped his chum resoundingly on the back.

"Thought you were to stick by the airplane," he said, with mock
severity.

Bob swung around, the worried look vanishing from his face.

"Hurray," he said. "So they didn't get you after all? When I saw you
punch that fellow I thought your goose was cooked."

"Saw me punch him? Why, where were you?"

"Oh, I had followed you," said Bob. Then he explained.

"Then when the attack began," he added, "I flew around overhead until
I saw my chance to return and land. I wasn't going to leave without
you. Presently, the government troops were beaten at the north. That
was only a feint on their part, anyhow, I believe, to engage the
attention of the rebels. For at once, heavy shooting broke out farther
down the valley. Sounded like the main body was attacking there. Then
the rebels scooted down that way to repulse the new attack, and I took
a chance and landed. Not a soul in sight. And here I am."

Jack was speechless. But the look in his eyes betrayed his emotion.

"Bob, I'm proud of you," said Mr. Hampton. "Well, let's hurry away
before it is too late."

Rafaela stepped from her place of concealment.

"Aren't you going to say farewell?" she asked.

Bob looked at her in astonishment. Mr. Hampton, with a twinkle in his
eye, viewed Jack ardently. The latter advanced with extended hand.

"Miss Calomares," he said, "I can't tell you how grateful I am. I hope
we shall meet again."

"Miss Calomares?" muttered Bob, under his breath, his eyes on the
beautiful girl. "Jack certainly has moved fast. I don't get this."

Mr. Hampton took pity on him.

"Miss Calomares," he said, leading Bob forward. "This is my son's
chum. He came with him tonight in his airplane."

The girl held out her hand. Bob took it as in a daze.

"Pinch me," he said, in an aside to Jack.

All heard the remark, and laughed at Bob's mystification.

"Come," said Mr. Hampton, and once more moved toward the door. Once
more, however, his steps were arrested by a noise outside. This time
they heard the shouts of many men approaching the house and crying
"Viva, Calomares."

"Too late," groaned Mr. Hampton. "They have driven off the attack, and
are returning."

Rafaela uttered an exclamation.

"Oh, I must go to my room before papa discovers me here," she cried.
She darted for the door, but paused to give them parting cheer. "Do
not give up hope," she said. "They will drink a great deal, and then
all will sleep very soundly. You may escape late tonight. Good-bye,"
and turning, she ran lightly down the steps.

Jack's eyes followed. At the turning, she paused, looked back, and
waved to him, then disappeared.

"Now what will we do?" said Jack.

"You boys hide behind the bed," said Mr. Hampton. "I'll close the
door, but I won't lock it this time, for on second thought I believe
if it were locked and Calomares came up to see me--as he frequently
does before retiring--it would make him suspicious. I shall leave it
unlocked, and then he will believe he left it so himself in his
haste."

"Dad," said Jack, "I have an idea."

"What is it? Out with it."

"Well, we are trapped here. Suppose we turn the tables."

"What do you mean?" asked Bob.

"Well, Dad," said Jack, turning to his father, "didn't you say Don
Fernandez comes to call on you before retiring?"

"Yes, we have become good companions. He guards me carefully, keeps me
a prisoner for his own ends, but he is a cultured man and we have much
in common."

"Father says," asserted Bob, "that you are being held prisoner in
order to make trouble between the United States and the Mexican
government."

"He is correct," approved Mr. Hampton. "Don Fernandez has not
attempted to conceal from me that that is his desire. He sent a demand
for a preposterous ransom, merely in order to precipitate action at
Washington, and he has been wondering why no action was taken."

"Well, that's what father thought," declared Bob. "So he has kept the
matter of your being kidnapped a secret. Instead of appealing to our
government, we set out to rescue you. Father says we must do our
utmost to avert trouble between Mexico and the United States."

"So that accounts for many things," said Mr. Hampton. "I'm glad to
have them cleared up. But we are forgetting your idea, Jack. What is
it?"

"Simply that we capture Don Fernandez and make him release us all
under a guarantee of safe conduct," said Jack.

"You see," he added, "Bob and I are both armed, and we can do it."

"Good for you, Jack," said Bob.

"I believe it can be done," said Mr. Hampton. "And here," he added,
listening, "comes our opportunity, if I am not mistaken. You boys get
behind the four-poster and wait until I give you your cue."

Noiselessly Mr. Hampton closed the door, as the boys went into hiding.
Then the older man resumed his seat by the table, picked up his book,
and appeared to be reading.

Quick, light footsteps sounded on the landing outside. There was a
pause, while Don Fernandez searched his pockets for the key to the
door. Unable to find it, he turned as if to depart. To three pairs of
ears, straining to hear his every movement, the interpretation was
clear. He believed he had locked the door and lost the key and was
about to depart. Mr. Hampton saved the situation by raising his voice,
and calling:

"Is that you, Don Fernandez? Will you not honor me by coming in? I am
eager to learn what has occurred."

The Don decided to try the door. To his surprise, it opened to his
touch. "I must have forgotten to lock it in my haste," he muttered,
and stepped into the room.

"Government troops," he said, advancing, "They thought to surprise us
but we have beaten them off decisively." He sat down heavily. "It has
been strenuous work," he said. "But that is over. Now to find the
assassin, if he has not already escaped."

"Assassin?" queried Mr. Hampton, in genuine surprise. He had not been
told the Don's belief regarding Jack.

"Yes," said Don Fernandez, violently. "That miserable Obregon." And he
proceeded to relate his version of Jack's arrival.

"Oh, but you are mistaken," said Mr. Hampton, coolly. "That was no
assassin, but my son. He came to attempt to rescue me."

Don Fernandez leaped to his feet, as if shot upward by a spring.

"Your son?" he cried. "Came to rescue you? Preposterous. Then, why are
you here?"

"Because," said Jack, stepping from hiding, with revolver leveled, "I
wanted to meet you."

"Yes, and so did I," said Bob, not to be outdone, as he emerged, also
with leveled weapon, from the other side of the four-poster.

Mr. Hampton quickly slipped the key into the lock of the door, turned
it and drew back. Don Fernandez saw the action. He glared from one to
the other of the three, and then sat down with a resigned shrug of the
shoulders.

"You wanted to meet me?" he said. "I am honored. But, Mr. Hampton,
there is not only one son but two!"

"Not exactly," said the American. "This lad"--laying a hand on Jack's
shoulder--"is my son, the young man you pursued for a time tonight.
This other"--placing his other hand on Bob's shoulder--"is my son's
chum."

"Well," said Don Fernandez, the faintest suggestion of a twinkle in
his eye, "now that you have met me, as you desired, what have you to
say?"

"Just this," said Jack, boldly, "we want you to permit us to leave
under safe conduct. We want to take father with us in Bob's airplane.
Oh, yes, it was my chum's airplane which your men stole in Long
Island. But we have gotten it back again."

"So?" said Don Fernandez. "Well, nothing surprises me tonight. And
where, may I ask, are Morales and Von Arnheim? I see you are wearing
their clothes."

"We have got them imprisoned," said Jack. "But we are in earnest, sir,
about this. We are armed and have the upper hand, and we mean to have
your protection. If you are armed, you had better give your weapon to
father."

"As your father very well knows," said the Don, "I never carry
weapons. And now"--with grave courtesy--"if you will permit me, young
sir, I would like to speak privately with your father."

At a nod of agreement from his father, Jack withdrew to the door,
followed by Bob, leaving the two older men in low-voiced conversation.
They spoke animatedly, and to the anxious boys there came more than
once a low chuckle of laughter from Don Fernandez while they could see
Mr. Hampton beginning to smile. At length, Don Fernandez beckoned
imperiously, and the boys approached.

He regarded them with twinkling eyes, but it was Mr. Hampton who acted
as spokesman.

"Boys," said he, "Don Fernandez consents. But I do not believe he was
influenced by fear for his life."

Don Fernandez stood up between the two chums, and put an arm over the
shoulder of each--or, rather, tried to, as they towered above him.

"No, it was not fear," said he. "But Mr. Hampton has told me a little
of what you have done, and I see it is useless to fight against Young
America. You are fine fellows. If I had a son"--wistfully--"I would
want him to be like you."




CHAPTER XXX

GOOD NEWS FOR ANXIOUS EARS


"Now to call Father," said big Bob.

He and Jack, escorted by several Mexicans of Don Fernandez' band who
had been informed by the Don himself that the boys were friends who
were to be treated with every respect, were approaching the radio
station of the Calomares ranch.

Jack was exuberant. Plans for the rescue of his father from the
stronghold of the rebel leader had not worked out just as proposed.
Yet the wild adventure upon which he and Bob had embarked had come to
a successful conclusion, after all. And he was correspondingly elated.

Jack and his father were close pals. And he knew that Bob and his
father were the same. He threw an arm over the shoulder of his chum.

"Your father will certainly be relieved," he said. "I imagine he has
been sitting up there at the radio station on our ranch in New Mexico
for hours, waiting to hear from you. I can just see him in there,
walking up and down impatiently, with that bow-legged old cowboy, Dave
Morningstar, tilted back in a chair, with his hat down over; his
eyes, smoking and never making a move."

"Won't he be delighted," said Bob. "Just won't he."

"And Frank, too," said Jack, thinking of the third chum, left behind
at the cave.

"Good old Frank," said Bob, warmly. "We've got to tell him as soon as
I've notified father."

"He certainly put up some fight, I'll bet," said Jack, thinking of the
hurried radio reaching them from the cave as they neared the Calomares
ranch in their airplane hours before. "And maybe he was hurt in that
fight with Morales. He said he licked the Mexican, but that was all we
heard. You remember? His voice was broken off after that."

"That's right," said Bob. "I hope nothing serious happened to him.
What a shame it would be if he was hurt, while here we came through
practically without a scratch."

All this time they had been walking across the starlit landing field,
where could be seen Bob's airplane, and now they drew near the
brightly-lighted radio station.

Entering the sending room they were confronted by Muller. That young
German operator, whose perspicacity almost had caused their undoing
and whom Jack earlier had floored with a blow on the chin, was sitting
in a chair reading. He had returned to the station after the attack
of the Mexican regulars had been beaten off.

Muller jumped to his feet, surprise giving way to anger, but before he
could draw and level the revolver swinging at his hip, one of the
Mexican guards accompanying the boys pushed them aside and thrust
himself forward.

"None of that," he said in Spanish. "The General has commanded that
these young Americanos be well treated. They are friends."

"Friends," muttered Muller, sullenly, nevertheless withdrawing his
hand from the revolver butt. "That wasn't a very friendly way to treat
me awhile ago."

He turned to Jack.

"And why, if you are friends," he demanded, "do you two appear in the
clothing of Herr von Arnheim and Captain Morales?"

"A number of events have occurred," said Jack, quietly. "That is why.
However, Don Fernandez has heard the tale, and that is sufficient. He
has given orders personally to these soldiers that we shall be
permitted to use the radio. That is why we are here."

"Is that so?" demanded Muller of the Mexican guards.

The spokesman of the pair nodded agreement.

"The General has so commanded," he said.

Grudgingly, Muller stepped aside. Here was a mystery, and he hated
mysteries. Besides, these two youths were Americans. He was a German
and although the war between their respective countries was at an end,
he could not bring himself to entertain kindly feelings toward them.
Like many Germans, he believed the United States responsible for the
defeat of his fatherland in the World War. He was working in the ranks
of Germans in Mexico to embroil the United States with that country.
Such war, he believed, would strike a blow at the prestige of the
hated Yankees.

"If the General has commanded," he said, stepping aside, "go ahead."

"Look here," said Jack, flushing at this grumpy attitude, but deciding
to do the manly thing, nevertheless, and extending his hand, "let
bygones be bygones."

After a moment's hesitation, Muller shook hands. To do him justice, it
is only fair to point out that he was sincere in his attitude toward
Americans, but misled.

"I haven't time to explain about that blow," said Jack, "but at the
moment it was necessary. Matters have changed since then. It was
nothing personal."

"Very well," said Muller, his grumpiness beginning to disappear
beneath the charm of Jack's manner. "Say no more. Now what is it you
want? Perhaps I can help you."

"We want to use the radio," said Jack, noting Bob's growing impatience
at their delay.

"What station do you want to call?"

"The Hampton ranch," interrupted Bob, who decided it was time to bring
this conversation to an end. He was in a hurry to talk with his
father.

"Are you calling Rollins?"

This reminder of the erstwhile traitor at the Hampton ranch brought
both boys to a realization that Muller was familiar with the manner of
calling their station, as undoubtedly he had handled or conducted
radio conversations with Rollins in the past.

"No, not Rollins," said Bob, shortly. It was all right for Jack to
shake hands with Muller if he wanted to. Jack and Muller had been
active opponents, and such an act was only sportsmanlike under the
circumstances. But Bob disliked the young German on sight. "Just let
me at the phone," he said, "and turn on the juice."

"Very well."

Muller turned stiffly and entered the power plant adjacent, while Bob
in a fever adjusted the headpiece. As the hum of machinery sounded
from the power plant, Jack laid a hand on Bob's arm.

"Look here, Bob. Wait a minute."

Bob regarded him inquiringly, his fingers reaching for the knobs on
the instrument box before him, preparatory to sending out his signal
call.

"What is it, now?"

"Well, you know old Frank will have his ear glued to the receiver at
the cave. Suppose you call your father, but tell Frank to listen in
and not interrupt."

"Right," said Bob. "Well, here goes." And he began calling the Hampton
ranch.




CHAPTER XXXI

CALM AFTER THE STORM


Meanwhile, as Jack had foreseen, Mr. Temple waited at the radio plant
at the Hampton ranch with ill-concealed impatience.

Dave Morningstar, hat pulled down over his eyes, sat in a chair tilted
back against the wall, watching him from beneath the brim. The only
signs of life about the ex-cowboy turned mechanic were the occasional
movements of the eyes, and the occasional refilling of his pipe, from
which lazy streamers of smoke now and again floated upward.

All the evening these two had held watch. And, as hour after hour
passed, with no word from the boys, Mr. Temple's anxiety rose to a
fever. He condemned himself for ever having given his consent to his
son and Jack starting upon so foolhardy an expedition as that of
attempting to rescue Jack's father from the rebel headquarters and fly
to safety with him in Bob's airplane.

Surely, he thought, the boys long since would have reached the ranch
and made their departure. They had promised to call him by radio from
the airplane the moment they started on their return flight. From
their failure to do so he argued the worst. Their expedition must have
come to grief, probably even now they were prisoners, perhaps--

But he shuddered to think of the alternative. He would not let himself
consider that possibility. In desperation he turned to Dave
Morningstar.

"Isn't there something we can do?" he asked imploringly.

The old ex-cowboy took his pipe from his mouth, spat deliberately to
one side, then brought the forelegs of his chair to the floor.

"Le's see," he said. "I been a'most asleep. Le's see. What say to
calling the cave?"

Mr. Temple eagerly grasped at the proposal.

"Yes, certainly," he said. "Why haven't I thought of that before?
Perhaps Frank has heard something."

He did not pause to consider that the party at the cave in all
likelihood was little better prepared than he with information. The
mere idea of doing something, of taking some action that would break
up this horrible spell of waiting, appealed to him in his excited
state.

But after hearing from Frank an account not only of the fight the
latter had had to recover the cave, after once having been
dispossessed, but also of the attempt to warn the Calomares ranch
ahead of the boys' coming which Morales had made, he began to wish he
never had called Frank.

"Think of it," he said to Dave Morningstar, after explaining the
situation. "In all likelihood all that clash of conversation in the
air put them on guard at the Calomares ranch. They were led to suspect
all was not well. And then when the boys landed they were captured.
That can be the only reason for our failure to hear from Bob and
Jack."

Dave attempted sympathetic protest, but Mr. Temple shook his head and
groaned.

"No, something has happened to them," he said. "Oh, I was a fool to
let them go. I'll never forgive myself. If only they were not injured.
If only they were merely made prisoner, I----"

"Hey," said Dave, "look at that signal bulb. Somebody's calling us."

"It's only Frank, calling back, I suppose," groaned Mr. Temple.

But Dave took up a headpiece and began adjusting the tuner knob. In a
moment he tapped Mr. Temple on the bowed shoulder.

"Listen here," he said, and clapped the headpiece over Mr. Temple's
ears.


Similar anxieties to those ruling at the Hampton radio station had
been in control at the cave during the evening hours.

Frank had been frightfully anxious as the hours wore on with no word
from the boys. The flight to the ranch was a short one of only fifty
miles. Surely, if they had been successful, Jack and Bob long ere this
would have called him by radio in accordance with their agreement.

The poor boy stamped up and down the cave in such a fret that Tom
Bodine and Roy Stone made repeated efforts to calm him, but without
success. They began seriously to fear the effect of this anxiety upon
his system, already fevered by the several hard fights through which
he had gone in the last thirty-six hours.

Mr. Temple's call had done nothing to assuage Frank's anxiety. If
anything it had increased it. As he put aside the headpiece, he looked
so woebegone that Tom Bodine went up to him and laid an arm over his
shoulder.

"Now, look here, kid," he began.

But before he could proceed, Frank's glance caught the light flashing
in the signal bulb, and he leaped to the headpiece and microphone with
a glad cry.

       *       *       *       *       *

"Father, we are all right. Mr. Hampton is freed."

At the cave in the mountains of Old Mexico and at the Hampton ranch
across the border in American territory, these welcome words uttered
in Bob's well-known voice were received with delight. Across mountain
and desert sped the message by radio. Modern science making possible
the utilization of the forces of the air brought this quick relief to
an anxiety that otherwise would have continued for hours at the least,
until Bob and Jack could have flown back to the ranch.

But neither Mr. Temple nor Frank took that thought into consideration.
To them radio telephony was an accepted fact, part of their daily
equipment for carrying on life.

What filled their minds to the exclusion of all else was, at first, a
sense of gratitude and thankfulness for the lucky outcome of the
adventurous mission of the two boys, and, in the second place, a
desire to learn the details.

"Now don't interrupt, Frank," said Bob. "Just listen while I talk to
father, and you can hear all about it."

Under this admonition Frank ceased the flood of eager questions he had
loosed and confined himself to listening. As the story of the
remarkable series of adventures undergone by Jack and Bob at the
Calomares ranch poured through the air, however, Frank, at times,
could not curb his quick tongue, and many an exclamation he let slip.
His hand, placed across the mouth of the microphone, however, acted to
prevent these exclamations from interrupting the flow of Bob's
explanation.

When Bob had finished his account, Jack took a turn. And at the
recital of his adventures, Frank began to laugh. Removing his hand
from the microphone, he interrupted his chum with the question:

"Now, who's the lady-killer?"

Jack, who at the moment, was telling of the part played by Senorita
Rafaela, blushed violently and grew indignant. Bob, standing near,
looked at him speculatively. Was old Jack hard hit by that little
Spanish beauty? Ordinarily, Jack would have answered Frank's joking in
kind. But to grow indignant! Bob feared his chum was smitten.

For a long time the three-cornered conversation was carried on through
the air, Mr. Temple and Frank both being eager to hear every detail
and compelling Jack and Bob to repeat their stories several times.

Finally, drawn by the long absence of the boys, Mr. Hampton appeared
at the radio station accompanied by Don Fernandez himself, and he and
Mr. Temple held a brief conversation.

At length it was decided that the next day Mr. Hampton, with Bob and
Jack, would fly back to the Hampton ranch in New Mexico. Frank, Tom
and Roy Stone were to ride for the border at the same time, after
another night's sleep at the cave. Morales and Von Arnheim, to whom
Don Fernandez spoke personally, were apprised of the turn of affairs,
and were told to stay at the cave, which was plentifully provisioned,
until a relief party from headquarters could reach them with mounts.

Then "good nights" were said, and at their three different points our
respective characters retired for the night, well pleased with the
outcome of their adventures.




CHAPTER XXXII

MORE ADVENTURE AHEAD


"Farewell, Senor Jack Hampton."

Jack clasped the sprightly Spanish girl's hand, reluctant to release
it. It was noon of the next day. Brilliant sunshine flooded the
landing field of the Calomares ranch. Bob already had clambered into
the pilot's seat of the airplane. Mr. Hampton stood to one side,
exchanging farewells with Don Fernandez.

"Not farewell, Senorita," said Jack, ardently. "We must meet again."

The girl shrugged.

"But where?" said she. "Will you come back to capture our castle
again?"

"No," said Jack, grinning. "But," he added, significantly, "I may come
back--to capture one of its inhabitants."

Low though his tone was, the words reached the ears of Donna Ana, the
ever-present duenna, and she glared at him. This was no way for a
brash young Americano to be speaking to the daughter of the great Don
Fernandez. Jack caught the glance and laughed. He turned to the
duenna and extended his hand.

"Farewell, Donna Ana," he said. "It's been such a pleasure to meet
you."

The wizened old duenna was nonplussed. She did not know whether to
resent this pleasantry or be gratified by it. Mechanically she
accepted Jack's extended hand.

At that moment, Bob called to him. Jack turned. Mr. Hampton already
had entered the airplane. They were waiting for him. Once more he
seized Rafaela's hand.

"Remember," he said, so low that only her ears could hear his words,
"you haven't seen the last of me."

She cast him an arch glance.

"Senor Jack is improving," she whispered. "He will be a courtier yet."

Then Jack climbed into his seat. A mechanic started the propeller, the
machine began to bump over the ground, and presently it was in the air
and climbing.

Bob spiralled upward until they were high above the ranch, and the
figures below seemed little manikins. Jack believed he could
distinguish Rafaela waving a lacy handkerchief, and leaned far over
the side to wave in reply.

Then they were off, zooming through the air, straight as an arrow for
the international boundary and the Hampton ranch beyond. The flight
was brief. Bob covered the distance of 150 miles in considerably less
than two hours.

"Look here," he said to his father, after greetings had been
exchanged, and the latter had thumped his big son so hard and often
that Bob dodged when further "love taps" came his way. "I'm not going
to stay here to be pounded into a jelly. Tell you what, father, that's
a long ride up here from the cave. Frank started early this morning,
but he cannot arrive for another day. Suppose I go back and pick up
him and Roy Stone, and leave Tom to bring in the horses?"

Reluctant though he was to let his son depart so soon after regaining
him, Mr. Temple was persuaded, and Bob set off. Far down in Old
Mexico, back trailing over the route they had followed in entering the
country, he saw three horsemen leading a fourth animal, and on
approaching close, saw they were his friends.

Landing near them, Bob called an explanation of his mission. Roy Stone
demurred at the proposal.

"Much obliged for the offer," he said, "but I'll ride along with Tom
Bodine, if it's all the same to you. I'm in no hurry to get anywhere,
and you fellows will be having your own reunion at your ranch. Take
your chum with you, but leave Tom and me. We'll be in with the horses
sooner or later. Each of us will have a spare mount now, and it'll be
an easy trip. Anyhow, I never did like those airplanes."

"Same here," said Tom Bodine, staring with awe at the machine. "You
couldn't get me in that thing on a bet."

Frank, accordingly, relinquished the reins of his horse to Tom Bodine,
and with "good-byes" to his friends clambered into the airplane with
Bob. Roy Stone obligingly spun the propeller, an accomplishment with
which his association with Von Arnheim had made him familiar, and once
more the plane soared upward and headed across the border.

At the ranch that night it was a jolly party that gathered around the
board, with Mr. Hampton, Mr. Temple and the three boys. Gabby Pete,
talkative as ever, was bursting with desire for information about all
their adventures. He had prepared a surprisingly good dinner in honor
of the occasion.

Rollins alone was not present. When told of Mr. Hampton's impending
arrival, he had begged Mr. Temple to let him go to a distant oil well
for several days until Mr. Hampton could be informed in detail of his
treachery in the past and the reason for it. This Mr. Temple had
agreed to.

Back and forth across the table flew the conversation and, when the
meal was at an end, all continued to sit around the table until a late
hour.


During the weeks that followed Bob and Frank spent many enjoyable
hours rambling on horseback over the surrounding country and taking
more extended trips by airplane. The love for the country of which
Jack had spoken on arrival, seized them, too. The bright hot days
succeeded by cool nights--for in New Mexico the air cools immediately
upon the setting of the sun--appealed powerfully to boys reared on the
seacoast. The absence of raw winds and fogs especially appealed to
them. The weather was something which could be counted upon. Every day
was fair.

So passed the weeks, with the boys under Jack's pilotage travelling
far and wide, scouting through the mountains to discover new beauties
of scenery, making visits to the ancient Spanish ruins at Santa Fe,
attending a rodeo at Gallup, to which came cowboys and cowgirls from a
vast stretch of territory to perform hair-raising feats of
horsemanship and exhibit well-nigh miraculous skill with the lasso.

A month after their advent, and when their summer vacation was not yet
half spent, Mr. Temple at dinner one night announced that before
ending his prolonged vacation from business--the first he had taken in
ten years--he planned to go to San Francisco to consult with the
manager of his western exporting office.

"Why, father," said Bob. "I've always wanted to see the city by the
Golden Gate, and I know the fellows feel the same way about it. What
do you say to taking us with you? We won't get in your way. And you
can drop us here on your way back East."

Smilingly, Mr. Temple gazed at the faces of the three eager boys. Jack
and Frank enthusiastically echoed their chum's appeal.

"Yes, do, Mr. Temple," said Jack. "That is, if we wouldn't be in your
way."

"Uncle, I'm crazy to see San Francisco," said Frank.

"Well, it's a good deal changed from the days of the Forty-Niners,"
said Mr. Temple, smiling. "You may have your hopes too high, and may
be disappointed."

"Oh, come now, father," said Bob. "If you're going to be there only a
week, it'll be worth while for us."

"Well, that's the length of time I planned to stay," said Mr. Temple,
thoughtfully. "But I'll be pretty busy while I'm there. Do you boys
feel you can keep out of mischief if left to yourselves?"

Mr. Hampton interrupted.

"I reckon they can, Temple," he said. "They saved the day for me. I'm
beginning to think they are a pretty self-reliant lot. If you can see
your way to doing so, take them along. The trip will be a fine
experience."

"All right, boys," said Mr. Temple. "But you'll have to leave your
airplane. If you are going to see San Francisco, you can't do it very
well by airplane. And, anyhow, I wouldn't care to see you tackle the
Rockies."

"All right, father," agreed Bob. "We'll be too busy seeing the sights
to want the plane, anyhow. When do we start?"

"In two days," said his father.

With this we take leave of the three chums, whose adventures on the
Mexican border have come to so successful a conclusion. But in the
next story of "The Radio Boys on Secret Service Duty" we shall follow
their further adventures after they reach the city by the Golden
Gate--adventures fully as thrilling as those on the Mexican border, in
which they become drawn into the plots of an international gang of
smugglers engaged in bringing Chinese coolies into the United States
in defiance of the Exclusion Laws.

THE END.




[Illustration: book.]

The

Radio Boys Series

BY GERALD BRECKENRIDGE

A new series of copyright titles for boys of all ages.

Cloth Bound, with Attractive Cover Designs

PRICE, 65 CENTS EACH

       *       *       *       *       *

THE RADIO BOYS ON THE MEXICAN BORDER

THE RADIO BOYS ON SECRET SERVICE DUTY

THE RADIO BOYS WITH THE REVENUE GUARDS

THE RADIO BOYS' SEARCH FOR THE INCA'S TREASURE

THE RADIO BOYS RESCUE THE LOST ALASKA EXPEDITION

       *       *       *       *       *

For sale by all booksellers, or sent postpaid on receipt of price by
the Publishers

A.L. BURT COMPANY

114-120 EAST 23rd STREET NEW YORK




[Illustration: book.]

The Ranger Boys Series

BY CLAUDE H. LA BELLE

A new series of copyright titles telling of the adventures of three
boys with the Forest Rangers in the state of Maine.

Handsome Cloth Binding.

PRICE, 65 CENTS EACH.

       *       *       *       *       *

THE RANGER BOYS TO THE RESCUE

THE RANGER BOYS FIND THE HERMIT

THE RANGER BOYS AND THE BORDER SMUGGLERS

THE RANGER BOYS OUTWIT THE TIMBER THIEVES

THE RANGER BOYS AND THEIR REWARD

       *       *       *       *       *

For sale by all booksellers, or sent postpaid on receipt of price by
the Publishers.

A.L. BURT COMPANY

114-120 East 23rd Street, New York




[Illustration: book.]

The Boy Troopers Series

BY CLAIR W. HAYES

Author of the Famous "Boy Allies" Series.

The adventures of two boys with the Pennsylvania State Police.

All Copyrighted Titles.

Cloth Bound, with Attractive Cover Designs.

PRICE, 65 CENTS EACH.

       *       *       *       *       *

THE BOY TROOPERS ON THE TRAIL

THE BOY TROOPERS IN THE NORTHWEST

THE BOY TROOPERS ON STRIKE DUTY

THE BOY TROOPERS AMONG THE WILD MOUNTAINEERS

       *       *       *       *       *

For sale by all booksellers, or sent postpaid on receipt of price by
the Publishers.

A.L. BURT COMPANY

114-120 East 23rd Street, New York




[Illustration: book.]

The Golden Boys Series

BY L.P. WYMAN, PH.D.

Dean of Pennsylvania Military College.

A new series of instructive copyright stories for boys of High School
Age.

Handsome Cloth Binding.

PRICE, 65 CENTS EACH.

       *       *       *       *       *

THE GOLDEN BOYS AND THEIR NEW ELECTRIC CELL

THE GOLDEN BOYS AT THE FORTRESS

THE GOLDEN BOYS IN THE MAINE WOODS

THE GOLDEN BOYS WITH THE LUMBER JACKS

THE GOLDEN BOYS ON THE RIVER DRIVE

       *       *       *       *       *

For sale by all booksellers, or sent postpaid on receipt of price by
the Publishers.

A.L. BURT COMPANY

114-120 East 23rd Street, New York




[Illustration: book.]

The Boy Allies

(Registered in the United States Patent Office)

With the Navy

BY ENSIGN ROBERT L. DRAKE

       *       *       *       *       *

For Boys 12 to 16 Years.

All Cloth Bound Copyright Titles

PRICE, 65 CENTS EACH

Frank Chadwick and Jack Templeton, young American lads, meet each
other in an unusual way soon after the declaration of war.
Circumstances place them on board the British cruiser, "The Sylph,"
and from there on, they share adventures with the sailors of the
Allies. Ensign Robert L. Drake, the author, is an experienced naval
officer, and he describes admirably the many exciting adventures of
the two boys.

THE BOY ALLIES ON THE NORTH SEA PATROL; or, Striking the First Blow at
the German Fleet.

THE BOY ALLIES UNDER TWO FLAGS; or, Sweeping the Enemy from the Sea.

THE BOY ALLIES WITH THE FLYING SQUADRON; or, The Naval Raiders of the
Great War.

THE BOY ALLIES WITH THE TERROR OF THE SEA; or, The Last Shot of
Submarine D-16.

THE BOY ALLIES UNDER THE SEA; or, The Vanishing Submarine.

THE BOY ALLIES IN THE BALTIC; or, Through Fields of Ice to Aid the
Czar.

THE BOY ALLIES AT JUTLAND; or, The Greatest Naval Battle of History.

THE BOY ALLIES WITH UNCLE SAM'S CRUISERS; or, Convoying the American
Army Across the Atlantic.

THE BOY ALLIES WITH THE SUBMARINE D-32; or, The Fall of the Russian
Empire.

THE BOY ALLIES WITH THE VICTORIOUS FLEETS; or, The Fall of the German
Navy.

       *       *       *       *       *

For sale by all booksellers, or sent postpaid on receipt of price by
the Publishers

A.L. BURT COMPANY

114-120 EAST 23rd STREET NEW YORK




[Illustration: book.]

The Boy Allies

(Registered in the United States Patent Office)

With the Army

BY CLAIR W. HAYES

       *       *       *       *       *

For Boys 12 to 16 Years.

All Cloth Bound Copyright Titles

PRICE, 65 CENTS EACH

In this series we follow the fortunes of two American lads unable to
leave Europe after war is declared. They meet the soldiers of the
Allies, and decide to cast their lot with them. Their experiences and
escapes are many, and furnish plenty of good, healthy action that
every boy loves.

THE BOY ALLIES AT LIEGE; or, Through Lines of Steel.

THE BOY ALLIES ON THE FIRING LINE; or, Twelve Days Battle Along the
Marne.

THE BOY ALLIES WITH THE COSSACKS; or, A Wild Dash Over the
Carpathians.

THE BOY ALLIES IN THE TRENCHES; or, Midst Shot and Shell Along the
Aisne.

THE BOY ALLIES IN GREAT PERIL; or, With the Italian Army In the Alps.

THE BOY ALLIES IN THE BALKAN CAMPAIGN; or, The Struggle to Save a
Nation.

THE BOY ALLIES ON THE SOMME; or, Courage and Bravery Rewarded.

THE BOY ALLIES AT VERDUN; or, Saving France from the Enemy.

THE BOY ALLIES UNDER THE STARS AND STRIPES; or, Leading the American
Troops to the Firing Line.

THE BOY ALLIES WITH HAIG IN FLANDERS; or, The Fighting Canadians of
Vimy Ridge.

THE BOY ALLIES WITH PERSHING IN FRANCE; or, Over the Top at Chateau
Thierry.

THE BOY ALLIES WITH THE GREAT ADVANCE; or, Driving the Enemy Through
France and Belgium.

THE BOY ALLIES WITH MARSHAL FOCH; or, The Closing Days of the Great
World War.

       *       *       *       *       *

For sale by all booksellers, or sent postpaid on receipt of price by
the Publishers

A.L. BURT COMPANY

114-120 EAST 23rd STREET NEW YORK




[Illustration: book.]

The Boy Scouts Series BY HERBERT CARTER

For Boys 12 to 16 Years

All Cloth Bound Copyright Titles

PRICE, 65 CENTS EACH

New Stories of Camp Life

       *       *       *       *       *

THE BOY SCOUTS' FIRST CAMPFIRE; or, Scouting with the Silver Fox
Patrol.

THE BOY SCOUTS IN THE BLUE RIDGE; or, Marooned Among the Moonshiners.

THE BOY SCOUTS ON THE TRAIL; or, Scouting through the Big Game
Country.

THE BOY SCOUTS IN THE MAINE WOODS; or, The New Test for the Silver Fox
Patrol.

THE BOY SCOUTS THROUGH THE BIG TIMBER; or, The Search for the Lost
Tenderfoot.

THE BOY SCOUTS IN THE ROCKIES; or, The Secret of the Hidden Silver
Mine.

THE BOY SCOUTS ON STURGEON ISLAND; or, Marooned Among the Game-Fish
Poachers.

THE BOY SCOUTS DOWN IN DIXIE; or, The Strange Secret of Alligator
Swamp.

THE BOY SCOUTS AT THE BATTLE OF SARATOGA; A story of Burgoyne's Defeat
in 1777.

THE BOY SCOUTS ALONG THE SUSQUEHANNA; or, The Silver Fox Patrol Caught
in a Flood.

THE BOY SCOUTS ON WAR TRAILS IN BELGIUM; or, Caught Between Hostile
Armies.

THE BOY SCOUTS AFOOT IN FRANCE; or, With The Red Cross Corps at the
Marne.

       *       *       *       *       *

For sale by all booksellers, or sent postpaid on receipt of price by
the Publishers

A.L. BURT COMPANY

114-120 EAST 23rd STREET NEW YORK




[Illustration: book.]

Our Young Aeroplane Scout Series

(Registered in the United States Patent Office)

BY HORACE PORTER

       *       *       *       *       *
For Boys 12 to 16 Years.

All Cloth Bound Copyright Titles

PRICE, 65 CENTS EACH

A Series of Remarkable Stories of the Adventures of Two Boy Flyers in
The European War Zone.

OUR YOUNG AEROPLANE SCOUTS IN FRANCE AND BELGIUM; or, Saving The
Fortunes of the Trouvilles.

OUR YOUNG AEROPLANE SCOUTS IN GERMANY.

OUR YOUNG AEROPLANE SCOUTS IN RUSSIA, or, Lost on the Frozen Steppes.

OUR YOUNG AEROPLANE SCOUTS IN TURKEY; or, Bringing the Light to Yusef.

OUR YOUNG AEROPLANE SCOUTS IN ENGLAND; or, Twin Stars In the London
Sky Patrol.

OUR YOUNG AEROPLANE SCOUTS IN ITALY; or, Flying with the War Eagles of
the Alps.

OUR YOUNG AEROPLANE SCOUTS AT VERDUN; or, Driving Armored Meteors Over
Flaming Battle Fronts.

OUR YOUNG AEROPLANE SCOUTS IN THE BALKANS; or, Wearing the Red Badge
of Courage Among Warring Legions.

OUR YOUNG AEROPLANE SCOUTS IN THE WAR ZONE; or, Serving Uncle Sam in
the Great Cause of the Allies.

OUR YOUNG AEROPLANE SCOUTS FIGHTING TO THE FINISH; or Striking Hard
Over the Sea for the Stars and Stripes.

OUR YOUNG AEROPLANE SCOUTS AT THE MARNE; or, Hurrying the Huns from
Allied Battle Planes.

OUR YOUNG AEROPLANE SCOUTS IN AT THE VICTORY; or, Speedy High Flyers
Smashing the Hindenburg Line.

       *       *       *       *       *

For sale by all booksellers, or sent postpaid on receipt of price by
the Publishers

A. L. BURT COMPANY

114-120 EAST 23rd STREET NEW YORK




[Illustration: book.]

The Jack Lorimer Series

BY WINN STANDISH

For Boys 12 to 16 Years.

All Cloth Bound Copyright Titles

PRICE, 65 CENTS EACH

       *       *       *       *       *

CAPTAIN JACK LORIMER; or, The Young Athlete of Millvale High.

Jack Lorimer is a fine example of the all-around American high-school
boys. His fondness for clean, honest sport of all kinds will strike a
chord of sympathy among athletic youths.


JACK LORIMER'S CHAMPIONS; or, Sports on Land and Lake.

There is a lively story woven in with the athletic achievements, which
are all right, since the book has been O.K'd. by Chadwick, the Nestor
of American Sporting journalism.


JACK LORIMER'S HOLIDAYS; or, Millvale High in Camp.

It would be well not to put this book into a boy's hands until the
chores are finished, otherwise they might be neglected.


JACK LORIMER'S SUBSTITUTE; or, The Acting Captain of the Team.

On the sporting side, this book takes up football, wrestling, and
tobogganing. There is a good deal of fun in this book and plenty of
action.


JACK LORIMER, FRESHMAN; or, From Millvale High to Exmouth.

Jack and some friends he makes crowd innumerable happenings into an
exciting freshman year at one of the leading Eastern colleges. The
book is typical of the American College boy's life, and there is a
lively story, interwoven with feats on the gridiron, hockey,
basketball and other clean honest sports for which Jack Lorimer
stands.

       *       *       *       *       *

For sale by all booksellers, or sent postpaid on receipt of price by
the Publishers

A.L. BURT COMPANY

114-120 EAST 23rd STREET NEW YORK




[Illustration: book.]

The Girl Scouts Series

BY EDITH LAVELL

A new copyright series of Girl Scouts stories by an author of wide
experience in Scouts' craft, as Director of Girl Scouts of
Philadelphia.

Clothbound, with Attractive Color Designs.

PRICE, 65 CENTS EACH.

       *       *       *       *       *

THE GIRL SCOUTS AT MISS ALLEN'S SCHOOL

THE GIRL SCOUTS AT CAMP

THE GIRL SCOUTS' GOOD TURN

THE GIRL SCOUTS' CANOE TRIP

THE GIRL SCOUTS' RIVALS

For sale by all booksellers, or sent postpaid on receipt of price by
the Publishers.

A.L. BURT COMPANY

114-120 East 23rd Street, New York




[Illustration: book.]

Marjorie Dean College Series

BY PAULINE LESTER

Author of the Famous Marjorie Dean High School Series.

Those who have read the Marjorie Dean High School Series will be eager
to read this new series, as Marjorie Dean continues to be the heroine
in these stories.

All Clothbound. Copyright Titles.

PRICE, 65 CENTS EACH.

       *       *       *       *       *

MARJORIE DEAN, COLLEGE FRESHMAN

MARJORIE DEAN, COLLEGE SOPHOMORE

MARJORIE DEAN, COLLEGE JUNIOR

MARJORIE DEAN, COLLEGE SENIOR

       *       *       *       *       *

For sale by all booksellers, or sent postpaid on receipt of price by
the Publishers.

A.L. BURT COMPANY

114-120 East 23rd Street, New York




[Illustration: book.]

Marjorie Dean High School Series

BY PAULINE LESTER

Author of the Famous Marjorie Dean College Series

These are clean, Wholesome stones that will be of great interest to
all girls of high school age.

All Cloth Bound Copyright Titles

PRICE, 65 CENTS EACH

       *       *       *       *       *

MARJORIE DEAN, HIGH SCHOOL FRESHMAN

MARJORIE DEAN, HIGH SCHOOL SOPHOMORE

MARJORIE DEAN, HIGH SCHOOL JUNIOR

MARJORIE DEAN, HIGH SCHOOL SENIOR

For sale by all booksellers, or sent postpaid on receipt of price by
the Publishers

A.L. BURT COMPANY

114-120 EAST 23rd STREET NEW YORK




[Illustration: book.]

The Camp Fire Girls Series

By HILDEGARD G. FREY

       *       *       *       *       *

A Series of Outdoor Stories for Girls 12 to 16 Years.

All Cloth Bound Copyright Titles

PRICE, 65 CENTS EACH

       *       *       *       *       *

THE CAMP FIRE GIRLS IN THE MAINE WOODS; or, The Winnebagos go Camping.

THE CAMP FIRE GIRLS AT SCHOOL; or, The Wohelo Weavers.

THE CAMP FIRE GIRLS AT ONOWAY HOUSE; or, The Magic Garden.

THE CAMP FIRE GIRLS GO MOTORING; or, Along the Road That Leads the
Way.

THE CAMP FIRE GIRLS' LARKS AND PRANKS; or, The House of the Open Door.

THE CAMP FIRE GIRLS ON ELLEN'S ISLE; or, The Trail of the Seven
Cedars.

THE CAMP FIRE GIRLS ON THE OPEN ROAD; or, Glorify Work.

THE CAMP FIRE GIRLS DO THEIR BIT; or, Over the Top with the
Winnebagos.

THE CAMP FIRE GIRLS SOLVE A MYSTERY; or, The Christmas Adventure at
Carver House.

THE CAMP FIRE GIRLS AT CAMP KEEWAYDIN; or, Down Paddles.

       *       *       *       *       *

For Sale by all booksellers, or sent postpaid on receipt of price by
the Publishers

A.L. BURT COMPANY

114-120 EAST 23rd STREET NEW YORK




[Illustration: book.]

The Blue Grass Seminary Girls Series

BY CAROLYN JUDSON BURNETT

       *       *       *       *       *

For Girls 12 to 16 Years

All Cloth Bound Copyright Titles

PRICE, 65 CENTS EACH

       *       *       *       *       *

Splendid stories of the Adventures of a Group of Charming Girls.

THE BLUE GRASS SEMINARY GIRLS' VACATION ADVENTURES; or, Shirley
Willing to the Rescue.

THE BLUE GRASS SEMINARY GIRLS' CHRISTMAS HOLIDAYS; or, A Four Weeks'
Tour with the Glee Club.

THE BLUE GRASS SEMINARY GIRLS IN THE MOUNTAINS; or, Shirley Willing on
a Mission of Peace.

THE BLUE GRASS SEMINARY GIRLS ON THE WATER; or, Exciting Adventures on
a Summerer's Cruise Through the Panama Canal.

       *       *       *       *       *

[Illustration: book.]

The Mildred Series

BY MARTHA FINLEY

       *       *       *       *       *

For Girls 12 to 16 Years. All Cloth Bound Copyright Titles

PRICE, 65 CENTS EACH

A Companion Series to the famous "Elsie" books by the same author.

MILDRED KEITH

MILDRED AT ROSELAND

MILDRED AND ELSIE

MILDRED'S MARRIED LIFE

MILDRED AT HOME

MILDRED'S BOYS AND GIRLS

MILDRED'S NEW DAUGHTER

       *       *       *       *       *

For sale by all booksellers, or sent postpaid on receipt of price by
the Publishers

A.L. BURT COMPANY

114-120 EAST 23rd STREET NEW YORK




[Illustration: And then quite suddenly the listening expectant boys
heard Jack's voice speaking to them just as plainly as if he stood in
the room.

(_The Radio Boys on the Mexican Border_) _Page 7_]