“Which two keys?” asked Nancy. “Let me see them. I don’t keep keys in coat pockets, ever. I have a drawer for them.”

Beer still didn’t look at her. Instead, he approached Poirot’s chair. When he was standing beside him, he opened his closed fist.

“What has he got there?” said Nancy impatiently.

“Two keys with room numbers engraved upon them, belonging to the Bloxham Hotel,” said Poirot in a solemn voice. “Room 121 and Room 317.”

“Should those numbers mean something to me?” Nancy asked.

“Two of the three murders were committed in those rooms, madame: 121 and 317. The witness who saw you run from the Bloxham Hotel on the night of the murders, he said that the two keys he saw you drop had numbers on them: one hundred and something, and three hundred and something.”

“Why, what an extraordinary coincidence! Oh, Monsieur Poirot!” Nancy laughed. “Are you sure you’re clever? Can’t you see what’s in front of your nose? Does that enormous mustache of yours impede your view? Someone has taken it upon himself to frame me for murder. It’s almost intriguing! I might have some fun trying to work out who it is—as soon as we’ve agreed I’m not on my way to the gallows.”

“Who has had the opportunity to put keys into your coat pocket between last Thursday and now?” Poirot asked her.

“How should I know? Anyone who passed me in the street, I dare say. I wear that blue coat a lot. You know, it’s ever so slightly irrational.”

“Please explain.”

For a few moments she appeared lost in a reverie. Then she came to and said, “Anyone who disliked Harriet, Ida and Richard enough to kill them . . . well, they would almost certainly be favorably disposed toward me. And yet here they are trying to frame me for murder.”

“Shall I arrest her, sir?” Stanley Beer asked Poirot. “Take her in?”

“Oh, don’t be ridiculous,” said Nancy wearily. “I say ‘frame me for murder’ and you immediately assume you must do it? Are you a policeman or a parrot? If you want to arrest somebody, arrest your witness. What if he’s not only a liar but a murderer? Have you thought of that? You must go across the road at once and hear the truth from St. John and Louisa Wallace. That’s the only way to put a stop to this nonsense.”

Poirot lifted himself out of his chair with some difficulty; it was one of those armchairs that didn’t make it easy for a person of his size and shape. “We will do that précisément,” he said. Then, to Stanley Beer, “No one is to be arrested at the present time, Constable. I do not believe, madame, that you would keep these two keys if you had indeed committed murder in rooms 121 and 317 of the Bloxham Hotel. Why would you not dispose of them?”

“Quite. I would have disposed of them at the first opportunity, wouldn’t I?”