I was trying to make sense of the complete design, and how the different parts of the ceiling related to one another, when a disconsolate Luca Lazzari rushed toward me, interrupting my admiration of the artistic symmetry above my head with his loud lament. “Mr. Catchpool, Monsieur Poirot, I must apologize to you most profusely! I have hurried to assist you in your important work, and, in doing so, I have put forward a falsehood! It was simply, you see, that I heard many accounts, and my first attempt to collate them was not successful. My own foolishness was responsible! No one else was at fault. Ah—”

Lazzari broke off and looked over his shoulder at the hundred or so men and women in the room. Then he moved to his left, so that he was standing directly in front of Poirot, and stuck out his chest in a funny sort of way. He put his hands on his hips. I think he was hoping to hide his entire staff from Poirot’s disapproving eye, on the principle that if they couldn’t be seen, they couldn’t be blamed for anything.

“What was your mistake, Signor Lazzari?” Poirot asked.

“It was a grave error! You observed that it was surely not possible, and you were right. But I want you to understand that my excellent staff, whom you see here before you, told me the truth of what took place, and it was I who twisted that truth to mislead—but I did not do it deliberately!”

“Je comprends. Now, to correct the mistake . . . ?” said Poirot hopefully.

The “excellent” staff, meanwhile, sat silently at large round tables, listening carefully to every word. The mood was somber. I made a quick survey of the faces and saw not a single smile.

“I told you that the three deceased guests asked to have dinner served in their rooms at a quarter past seven yesterday evening—each separately,” Lazzari said. “This is not true! The three were together! They dined as a group! All in one room, Ida Gransbury’s room, number 317. One waiter, not three, saw them alive and well at a quarter past seven. Do you see, Monsieur Poirot? It is not the great coincidence that I conveyed to you, but, instead, a commonplace occurrence: three guests taking dinner together in the room of one!”

“Bon.” Poirot sounded satisfied. “That makes sense of that. And who was this one waiter?”

A stout, bald man seated at one of the tables rose to his feet. He looked to be around fifty and had the jowlish tendency and mournful eyes of a basset hound. “It was I, sir,” he said.

“What is your name, monsieur?”

“Rafal Bobak, sir.”

“You served dinner to Harriet Sippel, Ida Gransbury and Richard Negus in Room 317 at fifteen minutes past seven yesterday evening?” Poirot asked him.