If Crawford was a real enemy, he would not be granting this favor. Harry was free to go to his room. He had pledged his word to his captor.
He moved unsteadily down the stairs that led to safety. Reaching the hall, he gained his usual composure, and moved by the closed doors, until he reached his own room. There he left the door ajar.
Sitting on the edge of the bed, Harry awaited the arrival of Crawford.
THE bearded man appeared some minutes later. He came through the door with the stealthiness of a cat, and closed the entrance behind him.
“Do not raise your voice,” he whispered. “Keep absolute silence. Do you know who I am?”
Harry shook his head.
“I didn’t think you recognized me,” said the man with the beard. “So I did not reveal my identity upstairs. I was afraid that you might not believe me.”
He leaned forward, and his voice sank to an almost imperceptible whisper, as he announced:
“I am Vic Marquette.”
“Of the secret service!” gasped Harry.
“Hush! You remember the time we worked together — “
“Yes,” replied Harry, “but I would never have recognized you.”
“I know it. This beard is a perfect disguise; for it is a real growth. I knew you the minute I saw you, when you came to Harvey’s Wharf.”
“Why didn’t you tell me who you were then?”
“That’s not my policy, Vincent. Those who have been friends once may be enemies later. I wanted to know your purpose here.”
“I do not know it, myself,” admitted Harry. “I have been told to report what goes on — “
“To The Shadow, I suppose,” interrupted Marquette.
“Yes,” replied Harry. “To The Shadow. I know that there is danger here — that Professor Whitburn is involved — but that is all.”
“What have you seen to date?”
“Nothing that I can explain. Last night — strange shapes appeared above the house. Something arose from the lake — like a phantom. To-night, I heard a tapping in the tower — I went up to see what was happening there.”
Vic Marquette laughed silently.
“Vincent,” he said, “you would have been dead this minute, if I hadn’t been watching you. Perhaps you do not know what this place is all about — but I suspect that The Shadow knows more than you.
“I am going to rely on you. I need your help. The Shadow saved my life once, and nabbed a bunch of counterfeiters for me. I believe he is on the square. I’m going to chance it.”
He rose from his chair, and looked at Harry steadily. Then he asked:
“Those things that you saw last night — in the darkness above the house. Tell me. What did they look like?”
“Ghosts,” admitted Harry.
The secret-service agent chuckled.
“They were aerial torpedoes,” he said. “The results of Professor Whitburn’s long experiments.”
“But they shone like phantoms — “
“Of course. Listen, Vincent. Professor Whitburn has made a remarkable contribution to scientific warfare. His aerial torpedoes are under perfect control.
“Last night, he sent them out from the big machines in the corners of the tower. They were ejected shortly after nine o’clock — “
“That’s why the static came in on the radio!” exclaimed Harry.
“Of course,” replied Marquette. “The torpedoes are under electrical control. Then they came back.
“The little lights were set to twinkle so that they could be observed from the tower. Then, when they were near by, they shone, for they are coated with a luminous paint, so we can observe their approach.”
“But what came out of the lake?”
“I was responsible for that,” said Marquette. “The professor believes that he can invent a torpedo which may be shot from a submarine, yet which will take to flight when it reaches the surface of the water.
“There is a torpedo tube beneath the house — in a room deep in the basement. I was there. When I received his signal, I shot the torpedo through an under-water cave, out into the lake.
“It rose, but failed to soar. The professor was watching from the tower.”
THE eerie events of the preceding night were now clear. But Marquette had further explanations.
“I shall start at the beginning,” he said. “Much has happened here. Originally, Professor Whitburn believed that he could revolutionize modern warfare by the invention of an aerial torpedo. He interested a man named Jonathan Graham.”
“Graham is dead,” said Harry.
“What? How?”
“Suicide, it is said. He fell from his office window.”
“That looks bad,” remarked the secret-service man. “When did it happen?”
After a moment’s thought, Harry gave the approximate date.
“Hm-m-m,” said Marquette. “So that’s why Stokes lost the newspapers, two days in a row. Whitburn may have learned it by letter — but I didn’t know about it.
“But we can discuss that some other time. Let me tell the important story.
“Graham made Whitburn financially independent. The professor took this place. The secret service learned what was going on — in part. I found out the rest.
“When I obtained a job here, Whitburn had one helper — a man named Blades. Then Stokes came along.
“Each one of us has different experimental work, and duties to perform. None of us could learn enough to be of value.
“If Whitburn has drawings — which seems likely — he makes them himself, and stows them away somewhere.
“Just as the torpedo was developing well, Blades was killed. A fly-wheel came off a machine which he was using in the cellar workshop.
“I wondered about it at the time. But the coroner called the death accidental. I had tipped off the secret service to stop any proceedings; but they never began.
“Marsh had been hired just before the death of Blades. That left three of us. A number of men applied; a fellow named Barrows got the vacant job. He was killed, too. He was working in a room where we keep chemicals.
“He made a mixture that formed a poison gas. It struck me as funny that he made the mistake he did; and I couldn’t figure why he didn’t get out the door in time.
“Then I had my experience. The old motor boat sank in the middle of the lake. Started to fill as I got away from the point of the island; I didn’t see it until it was too late.
“I had told the professor that I couldn’t swim, but didn’t mind running the boat. I meant that I was a poor swimmer — not that I was totally incapable. I managed to paddle the half mile to shore; the longest swim I ever made in my life.”
“Whew!” exclaimed Harry, as Marquette paused. “Looks like some one is out to get all of us. Who’s the man — Stokes?”
“Yes.”
“What about Marsh. Has he run into trouble?”
“Marsh,” replied Marquette, “is a different case. I think that Stokes has reached him. I believe that the object of these murders is twofold.
“First, to dispose of those who are not plotting against Whitburn; second, to install substitutes who are confederates of Stokes.
“Marsh may be one of them. If not, Stokes has worked on him, and has gained his cooperation.”
“Then my job was to have been taken by some other person?”
“That’s it, Vincent. But Professor Whitburn preferred your application to that of the man who was to work with Stokes. I haven’t been able to look at the list of applicants. That’s the trouble, here. I can’t cross the old man.
“As soon as you arrived, I knew that you had a purpose. I doubted that you were the man Stokes wanted. But I was afraid to reveal my hand until I was sure. Stokes must have known that you were looking at the tower last night because — “