“Knowing that we would assume he had started to shave, cut himself badly and stopped,” said Poirot. “And then, when he visited me at the lodging house, his beard had disappeared and his face was covered in cuts: to remind me that he cannot shave without lacerating his face. Eh, bien, if I believe this then I will assume that every cut I see upon his face is caused by shaving.”

“Why don’t you sound more excited?” I asked.

“Because it is so obvious. I arrived at this conclusion more than two hours ago.”

“Oh.” I felt deflated. “Wait a minute—if Samuel Kidd scratched his face on the tree outside Richard Negus’s open window, that means he might have climbed into the room and got his hands on the keys to 121 and 317. Doesn’t it?”

“There is no time to discuss the meaning now,” said Poirot in a stern voice. “We arrive at the station. It is clear from your question that you have not listened carefully.”

DR. AMBROSE FLOWERDAY TURNED OUT to be a tall, thick-set man of around fifty with wiry dark hair that was graying at the temples. His shirt was crumpled and missing a button. He had passed on instructions for us to go to the vicarage, so that was where we were, standing in a chilly hall with a high ceiling and a splintering wooden floor.

The whole place seemed to have been given over to Dr. Flowerday for him to use as a temporary hospital for one patient. The door had been opened by a nurse in uniform. Under different circumstances I might have been curious about this arrangement, but all I could think of was poor Margaret Ernst.

“How is she?” I asked, once the introductions were over.

The doctor’s face twisted in anguish. Then he composed himself. “I am allowed to say only that she is doing well in the circumstances.”

“Allowed by whom?” asked Poirot.

“Margaret. She will not tolerate defeatist talk.”

“And is it true, what she asks you to tell us?”

After a short pause, Dr. Flowerday gave a small nod. “Most people would not survive for this long after such an assault. Margaret has a strong constitution and a strong mind. It was a serious attack, but, damn it, I shall keep her alive if it kills me.”

“What happened to her?”

“Two thoroughly bad pennies from the top end of the village came to the churchyard in the middle of the night and . . . well, they did things to the Ives’ grave that do not bear repeating. Margaret heard them. Even in her sleep she is vigilant. She heard metal smashing against stone. When she ran out to try to stop them, they attacked her with a spade they had brought with them. They didn’t care if they beat her to death! That much was obvious to the village constable, when he arrested them some hours later.”