I resolved henceforth to include all details relating to Negus at the earliest opportunity, if only so that I wouldn’t have to hear Poirot say, “And Richard Negus?” over and over again.

“He turned up an hour before Harriet Sippel. He was the first of the three to arrive, but it wasn’t John Goode who dealt with him. It was a junior clerk, a Mr. Thomas Brignell. I also found out that all three of our murder victims traveled to London by train, not car. I’m not sure if you wanted to know that, but—”

“I must know everything,” said Poirot.

His obvious desire to be in charge and make the investigation his own both irritated and reassured me. “The Bloxham has some cars that it sends out to fetch guests from the station,” I told him. “It’s not cheap, but they’re happy to sort it out for you. Three weeks ago, Richard Negus made arrangements with John Goode for the hotel’s cars to meet him, Harriet Sippel and Ida Gransbury. Separately; a car each. All of it—the rooms, the cars—it was all paid for in advance, by Negus.”

“I wonder if he was a wealthy man,” Poirot mused aloud. “So often, murder turns out to be about money. What are your thoughts, Catchpool, now that we know a little more?”

“Well . . .” I decided to throw myself into it, since he’d asked. Imagining what was possible was a good thing in Poirot’s book, so I would allow myself to concoct a theory, using the facts as a starting point. “Richard Negus must have known about all three arrivals, since he reserved and paid for the rooms, but perhaps Harriet Sippel didn’t know that Ida Gransbury was also coming to the Bloxham. And perhaps Ida didn’t know that Harriet was.”

“Oui, c’est possible.”

Encouraged, I went on: “Maybe it was essential to the murderer’s plan that neither Ida nor Harriet should know about the presence of the other one. But if that’s so, and if Richard Negus, meanwhile, knew that he and both women would be guests at the Bloxham . . .” My well of ideas ran dry at that point.

Poirot took over: “Our trains of thought proceed along similar tracks, my friend. Was Richard Negus an unwitting accomplice in his own murder? Perhaps the killer persuaded him to entice the victims to the Bloxham Hotel supposedly for another reason, when all along he planned to murder all three of them. The question is this: was it vital for some reason that Ida and Harriet should each be ignorant of the presence of the other in the hotel? And if so, was it important to Richard Negus, to the murderer, or to both?”

“Perhaps Richard Negus had one plan, and the murderer had another?”