“I quite understand. It is a very difficult situation for you, Mr. Cavendish. I would like to ask you one question. Mr. Inglethorp’s reason for not returning last night was, I believe, that he had forgotten the latchkey. Is not that so?”

“Yes.”

“I suppose you are quite sure that the latchkey was forgotten⁠—that he did not take it after all?”

“I have no idea. I never thought of looking. We always keep it in the hall drawer. I’ll go and see if it’s there now.”

Poirot held up his hand with a faint smile.