“Cayley thinks he did it,” said Antony to himself. “That’s obvious. It explains why he wasted so much time banging on the door. Why should he try to break a lock when it’s so much easier to break a window? Of course he might just have lost his head; on the other hand, he might⁠—well, he might have wanted to give his cousin a chance of getting away. The same about the police, and⁠—oh, lots of things. Why, for instance, did we run all the way round the house in order to get to the windows? Surely there’s a back way out through the hall. I must have a look later on.”

Antony, it will be observed, had by no means lost his head.

There was a step in the passage outside, and he turned round, to see Cayley in the doorway. He remained looking at him for a moment, asking himself a question. It was rather a curious question. He was asking himself why the door was open.