IT was two or three minutes before the girl regained consciousness. She opened her eyes, and blinked as
she saw the flashlight.
Her head was resting on Harry's shoulder; she gasped as she realized that she had been captured. Then
her worried expression changed to a smile as she recognized Harry.
'Are you all right?' questioned Harry.
'Yes,' replied the girl. Then her expression became solemn. 'But are you safe—Harry?'
'What do you mean?' Harry's voice became suddenly severe. 'Tell me. What are you doing here?'
'I have come to warn you.'
'To warn me? I can hardly believe that—after what Bruce Duncan has told me.'
'Bruce Duncan!' The girl's exclamation was involuntary.
'Yes,' replied Harry. 'Bruce Duncan. Do not pretend that you do not know him. You are the girl I met in
the Pink Rat. You are also Arlette DeLand. Do you admit it?'
'Yes.'
'Why did you try to mislead me, then?'
'I couldn't help it,' said the girl. 'Please believe me. We must not waste time here. I can tell you
everything, later.
'But now you are in danger. That is why I came—to warn you. I tried to tell you over the phone one
night -'
Her voice broke. Then her expression changed to one of terror.
'Please,' she said, in a pleading voice. 'Believe me now. You must act at once. There are dangerous men
here. They may attack at any moment -'
'The men have left,' said Harry sternly. 'Both of them went away a few -'
'But there is another,' interrupted the girl. 'He is most dangerous of all. He came here an hour ago— one
man met him, and took him in the motor boat -'
A sudden realization dawned on Harry, as he gazed at the girl's eyes, and listened to her beseeching
words. He knew now that she was speaking the truth.
The enemy was already on Death Island! Stokes had brought back more than empty sacks; he had
transported a man from the mainland!
'I saw him from the woods,' explained Arlette. 'Believe me, when I say that the man is here. He is
powerful; he is superhuman -'
'Sh,' warned Harry. Rising, he helped the girl to her feet.
'I trust you,' he whispered. 'I believe you, Arlette. I understand everything—now. You must help me.
'I am here to protect an old man—Professor Whitburn. He is alone in the house. Our enemy may be
there now. Come!'
HE guided the girl to the door; and they entered the living room. The house was silent as a tomb. The
ticking of the clock on the mantel was audible.
'Have you a revolver?' questioned Harry.
Arlette shook her head.
'My only thought was to warn you,' she whispered. 'I found a canoe, after the motor boat had gone.
Harry, I have been here two nights, watching across the lake.'
Harry produced a revolver from his pocket, and gave it to the girl. He had slipped two automatics in his
coat when he had left his room.
For an instant he had qualms. Suppose Arlette was deceiving him! Then his doubts vanished. The girl
would not have saved him once, and warned him again unless she intended to be his friend.
Harry conducted Arlette to the kitchen. There she would not be seen by any one entering the house.
There was only one course to follow. He must search the premises, carefully watching for any traps that
might have been laid for him. The enemy might already be in the house.
It was more likely that he was still outside. In that case, Arlette could watch the door while Harry
searched. But first there was an important duty to make sure that Professor Whitburn was safe.
Harry stationed Arlette so that she could see the outer door, looking into the living room from the
kitchen.
'Be ready,' he whispered. 'If any one enters the house, shoot. Not too quickly; be sure it is an enemy -'
'I shall recognize the man who came here,' replied Arlette. 'He has never injured me; in fact, he once
saved me from harm. But your life is at stake, Harry, and—and -'
Harry pressed the girl's hand in the darkness. Then he left the room.
Harry crossed the living room, and knocked at the door opposite. Then he entered through the passage.
Professor Whitburn was at his desk, drawing diagrams on a sheet of paper. Harry stood a moment, in
silence; then, realizing that time was precious, he coughed to attract the old man's attention. The
professor looked up.
'Ah, Vincent,' he said. 'What do you wish?'
'Nothing, sir,' said Harry. 'That is, nothing for myself. I was about to retire, and I wondered if you might
have some late instructions -'
'None at all,' replied the professor brusquely. 'I would have called you before this, Vincent.'
A tiny alarm clock began to ring. It was on the desk, close by the professor.
'There is my reminder,' said the professor. 'I always have it set when I intend to work late.'
He turned off the alarm.
'Now I know that it is getting late,' he said. 'Also that it is time for me to take my pills. Where are they
now? Marsh set them out for me -'
He spied a bottle under some papers. He uncorked it, and took three tiny white tablets.
'Medicine is a nuisance,' remarked Professor Whitburn. 'Good night, Vincent.'
Harry had learned all that he desired to know.
The enemy had not yet arrived; at least he had not invaded the professor's study. The next task was to
search the house.
He went back to find Arlette.
To his surprise, the girl was not in the kitchen. Why had she left her post? Had she decided to search the
house? That was not in the arrangement.
Arlette would have remained here as she promised. There was only one possible explanation of her
disappearance. She had been surprised and captured!
The enemy could not have come from the outside, nor from upstairs; Arlette had commanded both the
door, and the steps which led to the second floor.
She must have been seized by some one lurking in the kitchen.
Harry thought of the stairs that led to the basement. He turned on his flashlight, and saw that the cellar
door was open. It was a heavy door, and had usually been shut and locked.
The gleam of his light revealed a small object on the floor. It was Arlette's hat. Her captor had carried her
to the cellar.
It required only a few minutes for Harry to investigate the cellar. There were several rooms; but all the
doors were open. His flashlight showed him the chemical laboratory, a workroom, and a storeroom; then
he came upon an archway.
Winding stone steps led downward.
The submarine chamber!
