“I didn’t know what you were doing until Dr. Balman said: ‘When she opened the door.’ Then I began to have a premonition, for I recalled the request you made at the first inquest.”
“What was that?” asked Jim.
“I asked Miss Keate not to mention the fact that when she came down the corridor after hearing the sound that she thought was a door closing and was actually——”
“Don’t!” I interrupted with a shudder.
“—was actually something else, she came to the door of Eighteen and opened it and stood there for a few seconds listening.”
“Why? Did she hear something? Or see anything?”
“No. But I reasoned that the guilty man must have still been in Room 18. It had not been a moment since the sound of the blow that—the blow that killed Dr. Letheny, and I knew that the man who did it could not have dragged Dr. Letheny’s body to the closet, locked the door, and made his escape before Miss Keate got to the door of Eighteen. Hence I knew that only the guilty man knew what she had done.”
“Did you plan that far ahead? Did you know you could work him to admit that knowledge?” cried Jim in honest amazement.
O’Leary shook his head, smiling ruefully.
“No. I am but human. But I plan to take every chance. Hoard every possible bit of evidence. That was small but conclusive.”