Poirot ignored my complaint. “For many years, Henry Negus worries in silence about his brother. He hopes, and no doubt also he prays, and when he has almost given up hope, it appears that his prayers are answered: Richard Negus has the visible upward perking a few months ago. He seems to be planning something. Perhaps the plan involved booking three rooms at the Bloxham Hotel in London for himself and two women he knew from his days in Great Holling, since we know that this is what he did. And then last night he is found dead at the Bloxham Hotel with a mongrammed cufflink in his mouth, in close proximity to his former fiancée, Ida Gransbury, and to Harriet Sippel, another villager who was once his neighbor. Both women have been murdered in the same way.”

Poirot came to a standstill. He had been walking too fast and was out of breath. “Catchpool,” he gasped, mopping his brow with a neatly folded handkerchief that he had pulled from his vest pocket. “Ask yourself what is the first event in this chain of events that I have presented to you. Is it not the tragic deaths of the vicar and his wife?”

“Well, yes, but only if we allow that they’re part of the same story as the three Bloxham murders. There’s no evidence of that, Poirot. I still contend that this poor vicar chap might be neither here nor there.”

“Just as la pauvre Jennie may be neither there nor here?”

“Exactly.”

We continued along the street.

“Have you ever tried to do a crossword puzzle, Poirot? Because . . . well, you know I’m trying to knock one together at the moment, one of my own?”

“It would be impossible to reside in such proximity to you as I do and not know, mon ami.”

“Yes. Right. Well, I’ve noticed something that happens when you’re trying to puzzle out a crossword clue. It’s interesting. Let’s say you have the clue ‘Kitchen utensil, three letters,’ and you have the letter ‘P’ as the first letter. It’s very easy to think, ‘Well, it has to be “pot” because that has three letters and begins with “P,” and a pot is a kitchen utensil.’ So you tell yourself it must be true, when all the while the right answer is ‘pan’—also three letters, also a kitchen utensil beginning with P. Do you see?”

“That example does not serve you well, Catchpool. In the situation you describe, I would think of both ‘pot’ and ‘pan’ as being equally likely to be correct. Only a fool would consider one and not the other when both fit perfectly.”