Poirot’s idea of telling a story quickly is rather different from most people’s. Every detail matters to him equally, whether it’s a fire in which three hundred people perish or a small dimple on a child’s chin. He can never be induced to rush to the nub of a matter, so I settled into my chair and let him tell it in his own way. By the time he had finished, I felt as if I had experienced the events first-hand—more comprehensively, indeed, than I experience many scenes from my life in which I personally participate.

“What an extraordinary thing to happen,” I said. “On the same night as the three murders at the Bloxham, too. Quite a coincidence.”

Poirot sighed. “I do not think it is a coincidence, my friend. One accepts that the coincidences happen from time to time, but here there is a clear connection.”

“You mean murder on the one hand, and the fear of being murdered on the other?”

“Non. That is one connection, yes, but I am talking about something different.” Poirot stopped promenading around the drawing room and turned to face me. “You say that in your three murder victims” mouths are found three gold cufflinks bearing the monogram ‘PIJ?’ ”

“That’s right.”

“Mademoiselle Jennie, she said to me quite clearly: ‘Promise me this: if I’m found dead, you’ll tell your friend the policeman not to look for my killer. Oh, please let no one open their mouths! This crime must never be solved.’ What do you think she meant by ‘Oh, please let no one open their mouths?’ ”

Was he joking? Apparently not. “Well,” I said, “it’s clear, isn’t it? She feared she would be murdered, didn’t want her killer punished and was hoping no one would say anything to point the finger at him. She believes she is the one who deserves to be punished.”

“You choose the meaning that at first seems obvious,” said Poirot. He sounded disappointed in me. “Ask yourself if there is another possible meaning of those words: ‘Oh, please let no one open their mouths.’ Reflect upon your three gold cufflinks.”

“They are not mine,” I said emphatically, wishing at that moment that I could push the whole case very far away from me. “All right, I see what you’re driving at, but—”

“What do you see? Je conduis ma voiture à quoi?”

“Well . . . ‘Please let no one open their mouths’ could, at a stretch, mean ‘Please let no one open the mouths of the three murder victims at the Bloxham Hotel.’ ” I felt an utter fool giving voice to this preposterous theory.

“Exactement! ‘Please let no one open their mouths and find the gold cufflinks with the initials PIJ.’ Is it not possible that this is what Jennie meant? That she knew about the three murder victims at the hotel, and that she knew that whoever killed them was also intent on killing her?”