“All it amounts to,” said Bill, “is the living-rooms downstairs⁠—dining-room, library, hall, billiard-room and the office rooms.”

“Yes, that’s all.”

“Well, the office is the most likely, isn’t it?”

“Yes. Except for one thing.”

“What’s that?”

“Well, it’s on the wrong side of the house. One would expect the passage to start from the nearest place to which it is going. Why make it longer by going under the house first?”

“Yes, that’s true. Well, then, you think the dining-room or the library?”