“Every murderer is probably somebody's old friend.”

“But I know human nature, my friend, and I tell you that, suddenly confronted with the possibility of being tried for murder, the most innocent person will lose his head and do the most absurd things.”

“Heather Badcock meant no harm. She never did mean harm, but there is no doubt that people like Heather Badcock (and like my old friend Alison Wilde), are capable of doing a lot of harm because they lack - not kindness, they have kindness - but any real consideration for the way their actions may affect other people. She though always of what an action meant to her, never sparing a thought to what it might mean to somebody else.”

“Pas encore. Qa m'amuse.""Really, Poirot!""Yes, my friend. I grow old and childish, do I not?”

“When you read the account of a murder - or, say, a fiction story based on murder - you usually begin with the murder itself. That's all wrong. The murder begins a long time beforehand. A murder is the culmination of a lot of different circumstances, all converging at a given moment at a given point. People are brought into it from different parts of the globe and for unforeseen reasons. [...] The murder itself is the end of the story. It's Zero Hour.”He paused.“It's Zero Hour now.”

“Is no one incapable of murder?”

“A murderer is seldom content with one crime.”