"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."