sent me a complete set of his plans. I am the only man—except the commander
himself—who has seen those diagrams.
'I have kept the plans here in my study. I took pains to conceal them, knowing their
importance. Should they fall into the hands of schemers, those plans could be sold to some
government other than the United States.
'To-night, I discovered that an intruder had been searching through this room. Fortunately,
the plans were untouched. At the same time, the fact that a search was made is proof that
enemies are close at hand. When stealth fails, attack follows. That is something that I have
learned through experience.
'We may, this very night, find invaders on this island. That is why I expect you to aid me in
repelling any foe. I can sense the imminence of an attack. Therefore, I intend to make an
inspection of this house before it comes.
'Remain here, both of you, until I return. Stay on guard, with revolvers ready. I shall be gone
but a short while. I wish to take advantage of the time that still remains to us.'
With this admonition, the professor clutched his automatic and stalked from the room,
closing the door behind him.
Stephen stood stolid. Polmore was nervous. The cat on the window sill, however, was no
longer perturbed. It curled among the papers and sleepily closed its eyes.
OUTSIDE the study, Professor Whitburn walked hastily through the corridor until he reached
a large central room where a clock was ticking loudly on a mantelpiece. The professor
turned and went to the side door that opened to the path toward the dock. He made sure
that the door was latched.
Moving to a flight of stairs, the professor ascended. He reached the second floor, then
approached a locked door. Drawing a key from his pocket, the professor opened the barrier
and went up a curving flight of stairs. He reached the old secluded tower.
This portion of the house formed a single room. It was almost pitch-dark; only a vague touch
of clouded moonlight came from a skylight at the top.
In the corners of the room were large machines, covered with white cloths. These were
devices for the projection of aerial torpedoes. The professor had experimented with them a
few years before. Partly dismantled, the machines were no longer used.
There was a table in the center of the room. Groping through the darkness, the professor
turned on a tiny light. He used this to find a pair of earphones and a mouthpiece. He made
attachments that put a short-wave radio into operation.
Clicks sounded by the little light. A few minutes passed. Then came a response.
The professor began to dispatch in a code of his own. He paused to hear the answer. Then
he resumed his sending. Although telephonic communication had been severed between
Death Island and the mainland, Professor Whitburn had made contact with some one in the
outside world.
The coded conversation continued. Sending and reception were terse. The professor
signed off abruptly. He replaced the earphones and turned out the light. His chuckle
sounded in the darkness. With surprising agility, the old man scrambled up on the table.
Stretching his bent form, Professor Whitburn managed to reach the skylight. He loosened a
clamp and pressed upward. Rusty hinges groaned; then came a puff of night air through the
opening. The professor tightened the clamp; bent downward and reached the floor. Softly,
he went down the tower stairs and closed the door behind him.
The professor had noted the time of the clock in the lower room. He glanced at his watch in
the dim light of the second-story hall. His trip to the tower had taken less than fifteen minutes.
Again, the professor chuckled.
Prowlers—the disturbed study—the dead telephone line: these troubled him no longer. By
means of the short-wave set, he had countered the thrust of impending danger. Time was
the only factor that remained to be met.
Professor Whitburn had established radio communication with a man named Burbank, a
person whom he had never seen. Yet he had followed Burbank's instructions to the letter.
The opened skylight; the unlocked door to the tower —both suited Burbank's request.
New confidence gripped Professor Whitburn. Through the old man's mind crept memories
of the past—when other danger had confronted him. He had been saved in that past by the
intervention of a powerful friend known as The Shadow. It was on The Shadow that the
professor depended in this present crisis.
For Burbank was the contact agent of The Shadow. By communicating with that distant
listener; by following Burbank's prompt instructions, Professor Whitburn had paved the way
for new aid.
Once again, the white-haired inventor was staking all upon The Shadow's prowess.
CHAPTER IV. THE TRAITOR
WHEN Professor Whitburn arrived back in his study, he found two anxious men awaiting
him. Stephen had become uneasy. Polmore's nervousness had increased. Both men
seemed relieved by their employer's return.
Quex, coiled in a corner of the window sill, stretched lazily when he saw his master. The cat
was used to the professor's sudden ways of leaving and returning. The old man smiled and
stroked the cat. Quex began to purr.
'Is everything all right, sir?' questioned Polmore. 'I was careful to latch the door after I came
back from the dock -'
'Everything is well,' interposed the professor.
'No sign of Bragg?' questioned Stephen.
'None,' returned Whitburn, abruptly.
Minutes passed. All of Whitburn's previous worriment had gone. Stephen began to share his
master's ease of mind. Polmore, however, showed new signs of nervousness. Whitburn
noticed it and studied the secretary with a quizzical look.
'I'm thinking about Bragg, sir,' declared Polmore. 'I wonder if he really went to the
mainland.'
'You told us the boat was gone,' reminded Whitburn.
'Yes,' assured Polmore, 'but Bragg may have had some other idea than an over-night visit
with friends in New Haven.'
'What makes you think he had that idea?'
'That's where he usually goes, sir. To New Haven.'
'Ah, yes. I had forgotten it. Go on, Polmore. Tell me what else Bragg may have had in mind.'
'Well'- Polmore was speculating—'you said that someone had been here in the study.'
'I did. Do you think it could have been Bragg?'
'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.'
