of the most simple sort, for it had no water to encounter. The encasing tube merely protected
the apparatus; and it was firmly fixed in position.
That tube had given The Shadow a solution to the problem of failing air. With gloved hands,
he began to detach the lower reflector. That done, he worked to remove the lenses and
other connections from within the tube itself.
PROFESSOR WHITBURN chortled. The Shadow was forming an air shaft to the clear
atmosphere above. Emptied of its equipment, the periscope tube formed a tunnel six inches
in diameter, leading straight upward. Only one problem remained. That was the upper
reflector.
Sudden dismay gripped Whitburn as he saw The Shadow blink a flashlight up through the
tube.
"The upper reflector is encased," exclaimed the professor. "It is larger than the tube. It is
screwed in place. Even if you break its bottom lens, you can not obtain air. There is an outer
glass, off at an angle -"
He shook his head as he paused. The Shadow was unscrewing a long bar from the
machine beside the old torpedo tube. With it, he could attack the lower lens of the upper
reflector; but as Whitburn had said, it would be impossible to curve this bar and reach the
outer glass.
The Shadow, however, had another plan. From beneath his cloak, he drew forth an odd
device. It was a rubber suction cup—one of those which The Shadow used to scale vertical
walls. The rubber disk was just a trifle smaller than the periscope tube.
Laughing softly, The Shadow used a clamp to fit the disk to the end of the steel bar.
He thrust the disked end of the bar straight up the periscope tube. Whitburn could hear the
squdge of the rubber sucker as it pressed against the lower lens at the top of the tube. Then
he began to revolve the bar. The professor gaped.
The suction cup had gained a grip. By twisting the bar, The Shadow was unscrewing the
mushroom cap that covered the upper end of the periscope tube. After a few moments, The
Shadow thrust the bar upward. A puff of air came down the shaft.
Jerking at the bar, The Shadow managed to detach the suction cup. Professor Whitburn
could hear the loosened cap rattle away from the top of the tube. The submarine chamber
was no longer a death trap. The prisoners could remain here indefinitely, with no danger of
suffocation.
Yet this passage to the outer air afforded no means of escape. Professor Whitburn
wondered what would follow. There would be no chance of communication with Bragg when
he came on the morrow. That meant prolonged entombment, with eventual starvation.
THE SHADOW had produced a sheet of paper. On it, he was printing penciled words. A
message—but to whom? Whitburn as puzzled; so was Stephen. Then they watched the
Shadow wad the message into a small packet which he tied with a short piece of stout cord.
A soft laugh. The Shadow turned and advanced to the steel door. Even then, the watchers
did not divine his purpose until they saw him stoop beside the cat that was waiting on the
steps. Quex offered no protest as The Shadow attached the message to the top of a thin
leather collar that the cat was wearing.
Lifting the docile feline, The Shadow carried Quex to the periscope tube. He lifted the cat
and pushed it into the six-inch shaft. Whitburn and Stephen could hear Quex clawing at the
smooth inner surface of the tube.
Holding the cat there with one hand, The Shadow reached to the machine and obtained the
lever, which still had the suction cup in place. He raised the disked end of the rod and used
it to support the cat within the periscope tube. With both hands, he thrust the rod slowly
upward.
Quex was riding up on an improvised elevator. The Shadow could hear the cat clawing and
shifting about. Then the top of the rod reached the ground level. The rod shook slightly as
Quex plopped off the suction disk and landed on solid earth. The Shadow withdrew and
removed the rubber cup.
"Quex will go to the front door!" exclaimed Whitburn. "Bragg will find him when he returns!
He will read the message! Does it tell him that we are imprisoned here?"
"Yes," responded The Shadow, in a laughing whisper. "Bragg will release us. We can wait
until the morning. Commander Dadren is warned. We have no need for immediate escape.
"Let us wait for Bragg. It is important that I see him. For I intend to take his place to-morrow. I
shall go to the address mentioned in the note that our enemy left upon your desk.
"We have air. An attempt to force the steel door is unnecessary. Particularly because I must
see Bragg when he returns. In the meantime, professor, I advise sleep for you and Stephen."
WHITBURN nodded. He looked about the room and shrugged his stooped shoulders as he
viewed the bodies of the four enemies who had fallen in their fight with The Shadow. Picking
an obscure corner, the old inventor sat down and rested his back against the wall.
Stephen chose another clear place. Stolidly, he watched Whitburn and saw the professor
begin to doze. That was sufficient. Stephen closed his eyes; five minutes later, he was also
asleep through sheer weariness.
The Shadow still stood beside the machine at the bottom of the periscope tube. Immobile,
he had become a living statue. Untired, he had no need of sleep. His keen eyes glistened
as they surveyed the dozing men. A soft laugh rippled from his hidden lips.
After that came silence. Ticking minutes left the scene unchanged. Sprawled bodies on the
floor of this odd chamber; two living men lay asleep in their corners.
And in the center of the stage, The Shadow. Victor of the fray, he had devised a way to
counteract the death trap. He had found a method of informing Bragg that his master was
locked in the submarine room.
Weird master of the scene, The Shadow was planning for the coming day. In the meantime,
spectral and immobile, he was biding the passing hours until dawn.
CHAPTER VII. AT CEDAR COVE
WHILE exciting events had been happening at Death Island, all had remained quiet at
Cedar Cove, the spot where Commander Joseph Dadren had established his headquarters
for submarine experiments.
Located on the Carolina coast, Cedar Cove was an ideal place for tests of the sort that the
commander was making. Five miles from the nearest town, isolated amid a forest of pine
trees, the cove was obscure and unfrequented.
Moreover, it was suited to secrecy. A single channel connected the cove with deep water.
On the innermost shore of the cove was a chasm between two low ledges of rock. This
formed a natural inlet wherein Commander Dadren housed his undersea craft.
Less than thirty feet in width, the cleft between the cliffs had been boarded over and topped
with a boat house. The entrance to the inlet was protected by heavy, doorlike screens which
could be raised and lowered.
Dadren's experimental craft was a small one. It remained undercover except when the
commander employed it for tests. Four men were constantly on duty in the boat house.
These were trusted aids, chosen from petty officers who had seen service in the United
States Navy.
Near the boat house was the building that served as headquarters. This was a
square-shaped structure, one story in height. It formed a type of
blockhouse, with an inner
court. Windows on the outside were protected by heavy bars; those on the court had
crisscrossed screens of stout wire.
The main hall of the headquarters house was a sort of clubroom where Dadren's workers
congregated. Off the hall were doors that led to smaller rooms. Some of these were quarters
for the men. Others were testing rooms that opened from side corridors.
At the rear was a large room that served as Dadren's laboratory. It had a steel door
connecting with an inner office. The little room was windowless.
A score of men constituted Dadren's crew. On this night some had retired; others were on
duty at the boat house. The rest, half a dozen in all, were gathered about the big fireplace in
the front section of the main hall.
Two solemn-faced men were acting as patrol. Together, they made the rounds of the square
house, while the others sat and chatted at the fireplace. A radio, turned down, was furnishing
a melodious musical program.
AMONG the men seated in the main hall was a quiet, watchful individual, less talkative than
his companions. This chap was Commander Dadren's secretary. He had been
recommended to the confidential post through Professor Arthur Whitburn. There was a
definite reason for the professor's recommendation. The secretary's name was Harry
Vincent. He was an agent of The Shadow.
Harry was speculating as he sat before the fire. He was thinking of the events that had
brought him here. Once—it seemed very long ago— Harry had aided The Shadow in giving
protection to Professor Whitburn. Following that episode, The Shadow had kept in
occasional contact with the old professor, through Harry.
One month ago, Harry had paid a visit to Death Island. There, he had learned of
Commander Dadren's experiment. Harry had reported to The Shadow. New contact had
followed with Whitburn. Through the old professor, Harry had gone to Dadren's headquarters
to take the job of confidential secretary.
Passing weeks had given Harry no inkling of impending trouble. Commander Dadren's
methods seemed airtight. None of his subordinates knew the full extent of his inventions.
Moreover, they were paired when they worked, so that no man could attempt any
surreptitious action without being observed by a companion.
The only weak point was the fact that Dadren had finished the extensive plans of his
completed submarine. Those plans were somewhere in his inner office; and every man at
Cedar Cove knew it. But outsiders had no chance of getting by the guards; and the system
of pairing workers made it impossible for a traitor—if one were in camp - to conduct a
secret search.
To-morrow, the commander intended to fly to Washington, accompanied by Hasker, the
mechanic who had charge of Dadren's amphibian plane. Harry had reported that fact to The
Shadow. He had added that nothing of a suspicious nature surrounded the proposed flight.
So to-night—the last night at Cedar Cove—Harry Vincent felt sure that any danger period
had been passed.
MIDNIGHT had arrived. Harry had been waiting for the hour. If The Shadow had new orders,
they were due. Harry rose from his chair; while others chatted he strolled to the radio and
turned the knob. He switched from the music of a Richmond station just in time for the
announcement of a program from WNX, New York.
The radio announcer was beginning a discourse on the merits of heavy winter overcoats
manufactured by a New York concern. His voice came over the air; and it carried an
emphasis on certain words:
"To prevent winter colds, follow the plain advice that will save many a trip to the doctor. Read
our free booklet 'When North Winds Blow.' Join with those who are wise. Make plans to be
healthy this winter -"
The announcer droned on. Harry heard no further words that were stressed. He knew that
the message had been given. Buried in the announcement was the emphasized order from
The Shadow:
"Prevent plane trip North with plans."
In the past, Harry had received many such messages from The Shadow. Somehow, his
mysterious chief had arranged a method of putting hidden sentences into the regular station
announcements. But on this occasion, Harry was startled by a difference.
At the end of the announcement, the speaker made a passing statement before the music
began. His words were:
"This program is an electrical transcription -"
A recorded program! The cleverness of the idea was impressive. This announcement must
have been spoken a few weeks ago, implanted upon a studio record that had been laid
aside until required. The Shadow had prepared it for an emergency.
Thus Harry realized that The Shadow might be far from New York. There had been no need
for him to visit Station WNX and arrange for a planted announcement. With a record ready,
it had simply been a case of telephoning instructions to use it.
Although he did not know the details, Harry had struck upon the exact truth. Before leaving
New York to rescue Professor Whitburn, The Shadow had ordered Burbank to call the
studio and state that Program R344 WC was to be used to-night. That had all been planned
beforehand.
would be well at Cedar Cove. For unless The Shadow returned to New York and canceled
his original instructions, the emergency order was sure to be received by Harry Vincent.
BACK in his chair near the fireplace, Harry was thinking quickly. He knew that a task lay
before him. To try to warn Commander Dadren would be a false step. As confidential
secretary, Harry might be able to give advice, provided that danger seemed present at
Cedar Cove. But so far, there had been no indication of an existing menace.
Harry smiled. Again, he was benefiting by The Shadow's forethought. He had received
instructions covering just such an emergency as this one. It was Harry's appointed duty to
create the thought of danger by action of his own.
Of all those stationed at Cedar Cove, Harry was the only one not paired with a companion.
He had arrived long after the others. His recommendation from Whitburn and his service as
Dadren's secretary had separated him from the others. In conformity with Dadren's system,
however, Harry was supposed to keep with the company except when performing actual
duty.
Therein lay Harry's opportunity. After a few minutes of planning, The Shadow's agent arose
and approached Wilkins, who rated the highest of those in the main hall. Harry remarked
that he had work to do for Commander Dadren.
"I have to type some letters for the skipper," he told Wilkins. "I'll use the machine in my room.
Let me know when the skipper comes in."
Wilkins nodded. Harry turned and entered a little room that opened from the hall. He turned
on the light and closed the door behind him. This room served as both bedroom and office,
so far as Harry's own work was concerned. A cot stood in one corner; opposite it was a
table with a typewriter.
Reaching beneath the table, Harry brought out what appeared to be the case of a portable
typewriter. He unlocked it and opened the top. Inside was a machine that bore a
resemblance to a usual portable. With it w
as a coil of insulated wire, with a plug on the loose
end.
Harry connected the cord with a wall socket. He was about to press a lever when he
remembered something. Seating himself at the table, he opened a drawer and brought out
a few letters that he had already typed. He laid them beside the real typewriter; then inserted
a blank sheet of paper and typed a letter halfway through.
That done, Harry stepped from the desk and pressed the lever on the portable machine.
There was a slight whirr, then the false typewriter began to click. Its action was irregular; at
the end of a series of clicks a little bell rang, and the carriage slid back to begin again.
Harry had received this device from The Shadow. It was serving an excellent purpose. Out in
the big hall, the men could hear the pounding of the keys, the sliding of the carriage. They
would swear, later, that they had heard Harry Vincent typing in his room.
WHILE the mechanism clicked, Harry stole toward the door and pressed the light switch.
With the room in darkness, he went to the window and softly opened it.
The window was barred with a crisscross wire grating; but Harry had previously loosened
the frame. He pushed the barrier outward, jamming it so that it hung as if hinged to one side
of the window. Harry dropped into the inner court.
He had long since planned this emergency trip. It required stealth, for too much noise might
attract the attention of men patrolling the halls about the block-shaped building. Crossing the
court, Harry reached the window of the laboratory.
Here were bars like those on the windows of his own room. Instead of attacking the frame,
Harry produced a pair of small but powerful wire clippers. Using both hands to gain more
pressure, The Shadow's agent began to clip the crisscross wires, just within the frame.
The task needed endurance. Each wire seemed tougher than the one before. But Harry had
confidence that he could accomplish the job with speed. He succeeded. Less than five
minutes after the departure from his room, he had the bottom and lower sides cut loose.
Harry pried the wires upward. As he had anticipated, the window, itself, was unlocked. With
a grating covering it, Commander Dadren seldom locked the sash. Harry opened the