It was like a mask had been pulled away from his face, uncovering a monster hidden beneath his friendly façade.

Mark nodded even though she couldn't see. He'd suddenly lost any desire to talk, and his plans for a perfect day washed away with the stream. The memories. They never let him go, not even for a half hour. They always had to rush back in, bringing all the horror.

Every danger loses some of its terror once its causes are understood.

Evil never goes unpunished, Monsieur. But the punishment is sometimes secret.

Nowadays, no one believes in evil. It is considered, at most, a mere negation of good. Evil, people say, is done by those who know no better - who are undeveloped - who are to be pitied rather than blamed. But, M. Poirot, evil is real! It is a fact! I believe in Evil as I believe in Good. It exists! It is powerful! It walks the earth!' He stopped. His breath was coming fast. He wiped his forehead with his handkerchief and looked suddenly apologetic. 'I'm sorry. I got carried away.

If there is anything good about nobility it is that it enforces the necessity of avoiding degeneracy