“How do you know that it did not? Patrick lived in Cambridge when he and Frances met and married. Jennie Hobbs was his servant then too. Perhaps she whispered something malicious about him in a friend’s ear and that friend, not being Harriet Sippel, chose to spread the malice no further.”

Poirot nodded. “You are right. It is a possibility.”

“Most people prefer not to spread ill will, and thank goodness for that,” said Nancy. “Perhaps in Cambridge there is nobody as malevolent as the person Harriet Sippel turned into, and nobody as eager as Ida Gransbury to lead a pious moral crusade.”

“I notice you do not mention Richard Negus.”

Nancy looked troubled. “Richard was a good man. He came to regret his contribution to the whole awful business. Oh, he regretted it deeply once he understood that Jennie had told a despicable lie, and once he saw Ida for the pitiless creature she was. He wrote to me a few years ago, from Devon, to say that the matter had been preying on his mind. Patrick and I were quite wrong to conduct ourselves as we did, he said, and he would never change his mind about that—marriage vows were marriage vows—but he had come to believe that punishment was not always the right path to follow, even when one knows that an offense has taken place.”

“That is what he wrote to you?” Poirot raised his eyebrows.

“Yes. I expect you disagree.”

“These affairs are complicated, madame.”

“What if, in punishing somebody for the sin of falling in love with the wrong person, one only brings greater sin into the world? And more evil: two deaths—one, of a person who has committed no sin.”

“Oui. This is precisely the sort of dilemma that creates the complication.”

“In his letter to me, Richard wrote that, Christian as he was, he could not bring himself to believe that God would wish him to persecute a sweet-natured man like Patrick.”

“Punishment and persecution are two separate things,” said Poirot. “There is also the question: has a rule or law been broken? Falling in love . . . enfin, we cannot help how we feel, but we can choose whether or not to act upon those feelings. If a crime has been committed, one must ensure that the criminal is dealt with by the law in an appropriate fashion, but always without personal venom and spite—always without the lust for vengeance, which contaminates everything and is indeed evil.”

“Lust for vengeance,” Nancy Ducane repeated with a shudder. “That was it exactly. Harriet Sippel was filled with it. It was sickening.”

“And yet, in telling the story, you have not once spoken angrily of Harriet Sippel,” I said. “You describe her behavior as sickening, as if it saddens you. You do not seem angry with her as you are with Jennie Hobbs.”