"If he's made a key to fit the door, I don't believe he's used it yet," Bob said after they had made a thorough examination of the room and its contents.
"But he must intend to."
"Of course."
"Then I reckon it's up to us to see that he doesn't."
"Of course again."
"To-night?"
"To-night what?"
"I mean does he intend to use it to-night?"
"I think it's more than likely. By his actions out there he evidently thinks that someone's not very far away."
"Then I see where we play detective."