there?"

"He peeped in at the door, saw the coast was clear, and went back
through the library. Remember, Miss Vaughan was unconscious. That
doesn't bother me. And another thing, Lester. How did Miss Vaughan's
father come to burst in on her and Swain like that? How did he know
they were in the arbour? It was dark and he couldn't have seen either
of them."

"He might have been walking about the grounds and overheard them."

"I don't believe it. I believe somebody told him they were there. And
only one person could have told him--that is Silva. No--there's only
one point I can't get past--that's the finger-prints."

And then I remembered.

"Godfrey," I cried, "there's one thing--I forgot to tell you. You
heard Swain remark that Vaughan was a collector of finger-prints?"

"Yes."

"And that he had a set of Swain's?"

"Yes."

"Well, when I told Miss Vaughan about the prints on her father's
robe, she ran to a book-case and got out a book. It had Vaughan's
collection in it, all bound together. But the page on which Swain's
were had been torn out."

Godfrey sat for a moment, staring at me spell-bound. Then he began
pacing up and down the study, like a tiger in its cage; up and down,
up and down.

"I'm bound to add," I went on finally, "that Hinman suggested a very
plausible reason for their disappearance."

"What was it?"

"He said they were probably destroyed by Vaughan himself, because of
his dislike of Swain. He said that would be characteristic of
Vaughan's form of insanity."

Godfrey took another turn up and down, then he stopped in front of my
chair.

"What did Miss Vaughan think of that explanation?" he asked.

"It didn't seem to impress her, but I don't remember that she made any
comment."

He stood a moment longer staring down at me, and I could feel the
intense concentration of his mind; then he ran his fingers impatiently
through his hair.

"I can't get it, Lester!" he said. "I can't get it. But I _will_ get
it! It's there! It's there, just out of reach." He shrugged his
shoulders and glanced at his watch. "I'm getting dippy," he added, in
another tone. "Let's go out and get a breath of air."

I followed him out into the yard--I knew where he was going--among the
trees and up the ladder. Silently we took our places on the limb;
silently we stared out into the darkness.

And there, presently, the strange star glowed and burned steel-blue,
and floated slowly down, and burst above a white-ro