“I have my lunch sent in.”

“And this room could not be entered without your knowledge while you were about the place?”

“It is impossible. The door is fitted with a powerful spring and a feather-touch self-acting lock. It cannot be left unlocked unless you deliberately prop it open.”

“And, with your knowledge, no one has had an opportunity of having access to this book?”

“No,” was the reply.

Carrados stood up and began to put on his gloves.

“Then I must decline to pursue my investigation any further,” he said icily.

“Why?” stammered the manager.

“Because I have positive reason for believing that you are deceiving me.”

“Pray sit down, Mr Carrados. It is quite true that when you put the last question to me a circumstance rushed into my mind which—so far as the strict letter was concerned—might seem to demand ‘Yes’ instead of ‘No.’ But not in the spirit of your inquiry. It would be absurd to attach any importance to the incident I refer to.”