"Yes, sir. At first I thought he might have left after he was in here. But then I began to figure
that he might still be on the island."
Professor Whitburn nodded; but his eyes were still questioning.
"You spoke of Bragg as a traitor," declared Polmore. "A traitor would resort to any trickery.
Bragg could have taken that boat around the island and landed somewhere on the other
side. There are several shallow places that would be suitable."
"I don't think Bragg would do that," objected Stephen. "Really, professor, he is -"
"Wait," interposed Whitburn, quietly. "Let us hear what Polmore has to suggest. Go on,
Polmore."
"I think we ought to search the island," declared the secretary. "It wouldn't be difficult. All
we'd have to do would be to go around the shore, looking for the boat.
"A good suggestion," nodded Whitburn. "Which of us should form the expedition?"
"Stephen and myself," replied Polmore, promptly. "You would be safe here, sir, with the door
locked. We could make the search in less than an hour."
"I shall consider it," decided the professor. "First, let us see if the telephone is still out
order."
HE went to the telephone and tried it. There was no response. Yet the old man persisted,
with his intermittent clickings of the hook. Five minutes—ten —still he repeated his trials. At
last, after a quarter hour had elapsed, the professor gave up the task.
"This is serious," he declared. "The telephone seldom remained out of order for so long a
time. Perhaps the cable has broken between here and the mainland. Unfortunately, there is
no way by which we can communicate with the telephone company."
"If we had the boat," reminded Polmore, "one of us could go ashore. If Bragg is on the
island, we might trap him. We would then have the boat, in addition."
"Well reasoned," declared Whitburn, in a commending tone. "Yes, Polmore, I believe that
we shall institute the search as you suggest. I think, however, that it would be unwise for me
remain here."
"Why so, sir?"
"If we should find Bragg, I would want to speak with him. Suppose you and I search,
Polmore. Let us leave Stephen here."
"That would hardly be fair, sir. Stephen can not well refuse to remain. Yet it was my
suggestion -"
"Very thoughtful, Polmore. Then you can stay."
"I—I would rather not, sir."
"You fear danger?"
"No, sir. But the responsibility—you must consider that. How can I protect something that I
have never seen? These plans of which you have spoken, they -"
"They are here in the study. That is all you need to know. It would be best for you to stay
here, Polmore."
"But the surface of the island is rough. You could not stand the heavy effort, professor.
Climbing over huge rocks -"
Whitburn waved his hand in interruption. He drew his large watch from his pocket, unhooked
it from the chain and placed it on the table.
"Time has flown," he remarked. "It is quarter to ten—fully half an hour since I returned from
my inspection of the house. Stephen"— he turned to the stolid man—"do you have a watch
with you?"
Stephen nodded.
"Then I shall leave mine here," decided Whitburn. "Polmore, we shall be gone until half past
ten. That is, unless we encounter Bragg in the meantime. Do you still object to staying here
on guard?"
"I guess not, sir." Polmore eyed the watch that the professor had placed on the desk. "Three
quarters of an hour isn't very long. You can let Stephen do most of the heavy work,
scrambling over the rocks."
"Another good suggestion," nodded Whitburn. "Come, Stephen, we must start."
USHERING Stephen from the study, Whitburn followed and closed the door behind him. The
two men passed through the corridor.
Stephen reached the outer door, opened it and stepped to the path. It was then that he felt
the professor clutch his arm.
"Wait!" ordered the old man, in a whisper. "Step back into the house! Say nothing!"
Stephen obeyed. As soon as they were inside, the professor closed the door with a slight
slam. He held Stephen silent. Minutes passed, one by one. At the end of five, the old man
delivered a soft, whispered chortle.
"The time is right," he decided. "Come, Stephen. Follow me. Make no noise. Have your
revolver ready."
Stephen nodded as he caught the whisper. He was puzzled by the professor's actions; he
became more perplexed when the old man led him back toward the study. Stephen thought
that they were going to make a new search upstairs, in case Bragg should be lurking there.
At the study door, the professor again gripped Stephen's arm. Then, with a quick movement,
Whitburn turned the knob, opened the door and sprang into the room. He held his automatic
ready. Stephen was close behind him, revolver leveled.
THEY caught Polmore in the act. The secretary was beyond the desk. He had opened
Whitburn's watch to get the key. He had pressed back the molding and had managed to
unlock the metal slide.
At the moment of Whitburn's return, Polmore had one hand in the empty space behind the
bookcase.
"Step away!" rasped Whitburn.
Polmore obeyed. Gunless, he had no other alternative. He had placed his revolver on the
table, never suspecting that Whitburn and Stephen would return so soon. The old professor
glared at his secretary.
"We know the traitor," he declared. "You managed only to deceive yourself, Polmore.
Thanks to Quex, on the window sill, I knew that some one had been prowling just before
Stephen arrived."
"It might have been Bragg. But you overplayed your hand. You wanted me to remain here.
Why? Because I had the watch. I suppose you have communicated that fact to my enemies.
You saw the secret of my hiding place.
"I tricked you, Polmore. As soon as I left my watch on the desk, you changed your tune. You
were willing then—anxious—to stay here. You are the traitor—you, the man I trusted!"
Polmore quailed beneath the professor's severe gaze. He tried to talk, but only wordless
gasps came from his trembling lips. It was plain that Polmore was an amateur accomplice.
The professor took advantage of the fact.
"You have been long in my employ," he declared. "Therefore, your treachery began at a
recent date. Some one bribed you to betray me. Who was the man?"
"He—he called himself Satterly," stammered Polmore. "Reginald Satterly. But—but I'm not
sure that was his name. He was a tall man - tall, with a red mustache—red hair—and he
wore a monocle."
"Did he talk like an Englishman?"
"Yes—but I think he was faking it. He was disguised—I'm sure of it— when I met him in New
York. He—well, he offered me a job at first. Then he paid me a thousand dollars. He wanted
me to make sure whether or not you had the plans."
"Have you seen him since?"
"No, sir. Truly, I haven't. I met a man that works for him. A rough-looking chap named Nuland.
In a cottage on the mainland. I—I signaled Nuland to-night."
"When you pretended to be looking for Bragg?"
"Yes, sir."
"Where is Bragg?"
"He went to New Haven. He asked me to speak to you this afternoon. I told him later that I
had, that you had said he could go. He won't be back until to-morrow morning."
"I see. You thought it might be easier with Bragg out of the way."
"Yes, sir."
PROFESSOR WHITBURN turned to Stephen. The faithful man was ready. He had listened
while the professor had forced the full confession from Polmore's lips. Stephen advanced
and pressed his revolver against Polmore's ribs. He backed the secretary into a corner.
"Hold him there, Stephen," ordered Whitburn. He glanced at his watch on the desk. "It is now
five minutes past ten. We have not long to wait."
"For what, sir?"
Stephen put the question without taking his eyes from Polmore.
"For a solution to our problem," chuckled Professor Whitburn. "We shall turn Polmore over
to a person who will question him further. Perhaps we can gain more facts pertaining to the
true identity of this briber who called himself Reginald Satterly.
"As for you, Polmore, you can forget all about those plans that I received from Commander
Dadren. So can the man who bribed you. The plans were of no use to me. When I suspected
that their hiding place was known, I destroyed them."
As he spoke in a dry tone, the old professor was stroking the cat upon the window sill. As he
paused, he felt Quex arch his back.
Alarmed, Whitburn turned toward the door. A sudden gasp came from the old man's lips.
Stephen heard it. He turned; then sullenly dropped his gun.
A man was standing in the doorway. Sallow-faced, with black mustache and hair, he wore
an evil leer. He was holding a revolver, covering those within the room. Behind him were
three ruffians, also carrying leveled guns.
Eric Hildrow had arrived.
A TROUBLED look came over Professor Whitburn's thin countenance. Trapped, the old
inventor knew that this enemy had heard his final words to Polmore. Moreover, Whitburn
recognized that Hildrow—though different from Polmore's description—must be the master
plotter.
Eyeing the professor, Hildrow sneeringly revealed the very fact.
"I am Reginald Satterly," scoffed the disguised man. "Also Logan Collender, whom you now
see. You are right: I am disguised. Disguised when I am Satterly; disguised when I am
Collender. Moreover, those identities are but a few of the many that I can assume.
"My real name; my true personality—those would not concern you. I prefer to keep them to
myself. As Satterly, I bribed Polmore. As Collender, I command these men who are with me.
They have watched this island from the mainland."
A pause. Twisting, the lips beneath the black mustache formed a sour, cunning smile. Then
Hildrow spoke in an insidious tone.
"Fortunately," he remarked, "Polmore left his key outside the door, with a note beside it. He
informed me that he would do so when he flashed his signal to the mainland. We expected
to find you alone, Professor Whitburn.
"You are right in assuming that I came to obtain those duplicate plans. But you did not divine
the purpose for which I wanted them. I intended to destroy those plans. You have saved me
the trouble.
"All that remains is the elimination of yourself. For good measure, I shall dispose of this man
Stephen also. You will not live, professor, to tell of this invasion, nor will Stephen be alive to
state how you died."
With this pronouncement, Eric Hildrow turned to growl an order. Nuland advanced, followed
by the others of the evil crew. Professor Whitburn and Stephen stood helplessly awaiting the
doom that was to be theirs.
Yet the old inventor was unflinching. Despite the closeness of death, he still had hope of
rescue. He had sent his message to The Shadow.
CHAPTER V. THE CLOSED TRAP
WHEN Eric Hildrow had led the way into the house on Death Island, he had adopted one
precaution. He had left a man on guard in the boat which the raiders had used to reach the
isle. This fellow was waiting close beside the little dock that lay on the shore below the
house.
The guard did not know what was taking place within. A dozen minutes had passed since
Hildrow and the crew had left. At first, the watcher had speculated on how soon the raiders
would return. He had been looking into the darkness that shrouded the big house.
Then his eyes had turned. He had heard a distant sound, high above the mainland. It was the
rhythmic purr of an airplane motor. Staring at an angle toward the sky, the lone guard tried to
make out the night flyer's lights.
He saw no blinks in the darkness. That surprised him, for he had located the direction from
which the plane was coming. While he still stared, the watcher heard the sound of the motor
fade. Complete silence followed.
The man at the dock laughed gruffly. There was no landing place on Death Island; nor was
there a field on the mainland anywhere near Lake Marrinack. He saw grief for any aviator
who would attempt to bring a ship to earth hereabouts.
When the noise of the motor did not resume, Hildrow's henchman decided that the plane
must have been further away than he supposed. Flying low, it could have passed beyond the
wooded stretches of the mainland.
The man's verdict was completely wrong. The sound that he had heard was closer and
above the skull-like cliff at the head of Death Island.
SHROUDED in absolute darkness, an autogyro was settling silently upon the island. With its
windmill blades retarding its vertical drop, the ship was responding to the guidance of a
master pilot.
Keen eyes were staring downward through the night. The Shadow, in response to the call
received through Burbank, was coming to the aid of Professor Arthur Whitburn. Winging
northward from a field near New York City, The Shadow had reached his chosen goal.
A clump of blackness in a shiny sheet of black. Such was Death Island, in the center of Lake
Marrinack. Nevertheless, The Shadow's keen eyes had discerned the blotty outline of his
objective. With Death Island found, he had picked another mark.
That was the whitened roof of Professor Whitburn's house. Tall trees held it in darkness
during the beginning of The Shadow's descent. But as he boldly dropped his flying windmill
toward the center of the island, The Shadow caught the faint outline of the landing spot he
wanted.
A soft laugh sounded by the controls of the autogyro. The tower at the back of the roof was
plain, now that the view was closer. Piloting his ship with uncanny skill, The Shadow picked
the space in front of the projecting tower. Like a winged creature from the outer spaces, the
autogyro settled amid the trees and came to a perfect landing on the roof of the house.
The wheels rolled forward for a single turn. The ship wavered slightly, then remained still.
Nosed almost against the house tower, the autogyro was resting in an area but little larger
than its own dimensions.
Motion in the darkness. The Shadow was alighting from the ship. Invisible amid the
enshrouding night, he moved forward to the square tower. In agile fashion, this mysterious
visitor swung up toward the skylight that Professor Whitburn had left opened in anticipation
of his arrival.
TIME had elapsed since Eric Hildrow and his
ruffians had entered the house. Down in the
hallway beside the outer door, Nuland and two others were holding Professor Whitburn and
Stephen against the wall. Hildrow had left the prisoners with Nuland while he had made a
trip with Polmore.
The two were returning. They arrived from a doorway that led to the cellar. Hildrow was
smiling in his insidious fashion. He stopped to face Professor Whitburn and spoke in his
sarcastic tones.
"Polmore has shown me your submarine chamber," remarked Hildrow. "An interesting
room, professor. I understand that you once conducted experiments with torpedoes from
that spot. The machines there interested me, even though they are partly dismantled. I also
noticed the periscope that you did not remove.
"But most of all"—Hildrow was leering villainously—"I observed that the chamber is
practically air-tight. Once you and Stephen are locked within that room, your doom will be
assured. So, professor, I shall put your submarine chamber to a new use. It will become your
tomb."
Turning to Polmore, Hildrow put a question. Polmore nodded and brought an envelope from
his pocket. Hildrow received the envelope and looked at Whitburn.
"A note," remarked Hildrow. "from Polmore to Bragg. When Bragg returns to-morrow, he will
report in your study, as usual. This message will tell him that you have left the island. Bragg
will come to New York, to find you at the place designated in the note.
"Do you admire my cleverness, professor? You should. By permitting Bragg to return and
leave unmolested, I shall create the impression that all is well on Death Island. I do not care
to remain hereabouts with my companions. We shall leave immediately after placing you
and your man in the submarine room.
"Ah, yes!" Hildrow leered as he caught a glimmer in the professor's eyes. "You are thinking
of something that you hoped I had forgotten. You had an idea that I had overlooked your cat.
Bragg might suspect something if he found the animal here alone. Get the cat, Nuland; take
it to the submarine room along with the men."
WHILE Nuland headed toward the study, Hildrow motioned to the other men. They marched
Whitburn and Stephen toward the cellar stairs, where Polmore pointed the way.
As the armed men descended with the prisoners, Nuland appeared with Quex. The tiger-cat