“Yes, I’m afraid so,” said Henry Negus.

“A recluse! I ask you, does this sound like a man who would indulge himself in sherry and cake, and gossip in a cavalier fashion with two women in a fancy London hotel? No! The man who received the afternoon tea from Rafal Bobak, and for whom Thomas Brignell fetched the sherry, was not Richard Negus. This man, he complimented Mr. Brignell on his efficiency and said something approximating the following: ‘I know I can rely on you to sort this out, since you are so efficient—bill the food and beverages to me, Richard Negus, Room 238.’ His words were calculated to make Thomas Brignell believe that this man, this Richard Negus, was familiar with his level of efficiency, and that therefore they must have encountered one another before. Mr. Brignell might feel a little guilty, perhaps, because he does not remember his previous dealings with Mr. Negus—and he will resolve not to forget him again. He will remember from now on this man whom he has met twice. Naturally, working in a large London hotel, he meets people all the time, hundreds every day! It often happens, I am sure, that guests know his name and face while he has forgotten theirs—after all, they are simply, en masse, ‘the guests’!”

“Excuse me, Monsieur Poirot, I beg your pardon.” Luca Lazzari hurried forward. “Broadly speaking, you are quite right, but not, as chance would have it, in the case of Thomas Brignell. He has an exceptional memory for faces and names. Exceptional!”

Poirot smiled appreciatively. “Is that so? Bon. Then I am right.”

“About what?” I asked.

“Be patient and listen, Catchpool. I will explain the sequence of events. The man impersonating Richard Negus was in the lobby of the hotel when Mr. Negus checked in on Wednesday, the day before the murders. Probably he wanted to survey the territory in preparation for the role he was to play later. In any case, he saw Richard Negus arrive. How did he know it was Richard Negus? I will come back to that point. Suffice to say, he knew. He saw Thomas Brignell undertake the necessary paperwork and then hand Mr. Negus the key to his room. The following evening, after posing as Mr. Negus to receive the afternoon tea and then going outside to dispose of it, this man is on his way back to Room 317 and he passes Thomas Brignell. He is a quick-thinking individual, and he sees a superb opportunity to consolidate the misleading of the police. He approaches Brignell and addresses him as if he, this impostor, were Richard Negus. He reminds Brignell of his name and alludes to a previous meeting.