"While your men are bringing the microscope," Ned went on, coolly, "I want to ask you a few questions."
"Go ahead," laughed the chief, wondering what sort of insanity this was.
"Who sat in this chair last?" asked Ned.
"Why, the last visitor, of course."
"Can you now recall his name?"
"Curtis."
"How was he dressed?"
"In a blue suit."
"Where is he now?"
"I don"t know. He said he would return as soon as the officers came back from the submarine."
"Yes he will!" Jimmie broke in.
"Does he belong here?" asked Ned.
The chief pointed to the west.
"Over in the navy yard," he said.
"So the blue suit he wore was a naval uniform?"
"Exactly."
The chief touched a bell on his desk and a policeman opened the door at the back of the room, connecting with the sergeant"s room, and looked in.
"Get a microscope," the chief ordered, "and keep quiet about what is going on in here."
The sergeant nodded and went out.
"What did you say about that smear on the arm of the chair?" asked the chief, then.
He was beginning to understand that there was something besides mental trouble at the bottom of Ned"s inquiries.
"I think," was the reply, "that an inspection of the spot will reveal a rubber composition used princ.i.p.ally by the thieves of Paris as a paint to prevent palm and finger lines and whorls showing on things they take hold of."
The chief looked at the spot critically.
"Also, shreds from a blue uniform," Ned continued.
"We shall see," replied the chief.
The microscope was soon brought in, and then a close examination of the spot on the arm of the chair was made by the chief.
"What do you find?" asked Ned.
"I really can"t say what it is," was the reply.
Ned took from a pocket a bit of the waste he had brought from the dynamo room of the submarine.
"Look at this," he said, "and see if the material in it appears to be the same as that on the chair. I mean, of course, the smudge on it."
The chief turned his instrument on the waste.
"It is the same," he declared, in a moment, "and I"d like to know where you got it."
"Do you find blue threads--well, not threads, exactly, but bits of fuzz--in the waste, too?"
"Yes, but the trace is faint."
"Well," Ned said, "the man who killed Lieutenant Scott is the man who gave you the information you speak of. He sat in this chair not long ago. I would advise a search for him."
"But he agreed to come back." "Of course he never will," Ned said.
"Now, here is another point. You are going to have the Sea Lion searched?"
"Yes."
"Well, your men will find the body of Lieutenant Scott lying on a couch there. In that case, they will doubtless arrest the two boys I left on watch there?"
"Certainly."
"And that will give the man who left this blur on the arm of this chair not long ago a chance to make off with the boat. I reckon you"ll do well to look after that part of the case, for the submarine belongs to the Secret Service department of the Government, and Uncle Sam has use for it just at this time."
"The Secret Service department?" repeated the chief. "He said she was a scout boat Lieutenant Scott was going to coast south with."
"Did he say why he suspected that Lieutenant Scott was in danger?"
asked Ned.
"He said you boys were suspicious characters who claimed to be able to operate a submarine, and that Scott was inclined to try you out."
Ned took a long envelope from a pocket of his coat and pa.s.sed it, unopened, to the chief.
"Read the letter inside," he said, "and then get me to the Sea Lion as quickly as possible."
The chief opened the envelope and read the single sheet of typewritten paper it held.
"From the Secretary of the Navy!" he exclaimed.
"Exactly."
"I don"t need to ask if you are the Ned Nestor mentioned in the letter, then. I saw a picture of you in a San Francisco newspaper, not long ago, and now recognize you as the boy referred to."