"Besides," I went on, "if the yogi did it, how did he get back into the house before we got 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."