“Well . . . I suppose he came to the hotel, cufflinks in pocket, and went to each of the three rooms in turn. He probably started where we did, with Ida Gransbury in Room 317, and worked his way down so that he would be able to leave the hotel fairly quickly after killing his final victim—Harriet Sippel in Room 121, on the first floor. Only one floor down and he can escape.”

“And what does he do in the three rooms?”

I sighed. “You know the answer to that. He commits a murder and arranges the body in a straight line. He places a cufflink in the person’s mouth. Then he closes and locks the door and leaves.”

“And to each room he is admitted without question? In each room, he finds his victim waiting with a most convenient drink for him to drop his poison into—drinks that were delivered by hotel staff at precisely a quarter past seven? He stands beside his victim, watching as the drink is consumed, and then he stands for a little longer as he waits for each one to die? And he stops to eat supper with one of them, Ida Gransbury, who has ordered a cup of tea for him too? All these visits to rooms, all these murders and putting of cufflinks in mouths and very formal arranging of bodies in straight lines, with feet pointing toward the door, he is able to do between a quarter past seven and ten past eight? This seems most unlikely, my friend. Most unlikely indeed.”

“Yes, it does. Have you got any better ideas, Poirot? That’s why you’re here—to have better ideas than mine. Do please start any time you wish.” I was regretting my outburst by the time I’d finished the sentence.

“I started long ago,” said Poirot, who thankfully had not taken umbrage. “You said that the killer left a note on the front desk, informing of his crimes—show it to me.”

I took it out of my pocket and passed it across to him. John Goode, Lazzari’s idea of perfection in the form of a hotel clerk, had found it on the front desk ten minutes after eight o’clock. It read, “MAY THEY NEVER REST IN PEACE. 121. 238. 317.”

“So the murderer, or an accomplice of the murderer, was brazen enough to approach the desk—the main desk in the lobby of the hotel—with a note that would incriminate him if anyone saw him leaving it,” said Poirot. “He is audacious. Confident. He did not disappear into the shadows, using the back door.”

“After Lazzari read the note, he checked the three rooms and found the bodies,” I said. “Then he checked all the other rooms in the hotel, he was very proud to tell me. Fortunately, no other dead guests were found.”