“Well,” I said, encouraged, “as the person who entered did not do so by the window, nor by miraculous means, it follows that the door must have been opened from inside by Mrs. Inglethorp herself. That strengthens the conviction that the person in question was her husband. She would naturally open the door to her own husband.”

Poirot shook his head.

“Why should she? She had bolted the door leading into his room⁠—a most unusual proceeding on her part⁠—she had had a most violent quarrel with him that very afternoon. No, he was the last person she would admit.”

“But you agree with me that the door must have been opened by Mrs. Inglethorp herself?”