"Let me see!" I cry in amazement.

"Stand back!" the Warden commands. "This knife has been stolen from the shoe shop. On whom did you mean to use it?"

"Warden, I didn't even know I had it. A fellow dropped it into my pocket as we—"

"That'll do. You're not so clever as you think."

"It's a conspiracy!" I cry.

He lounges calmly in the armchair, a peculiar smile dancing in his eyes.

"Well, what have you got to say?"

"It's a put-up job."

"Explain yourself."

"Some one threw this thing into my pocket as we were coming—"