Many homicidal lunatics are very quiet, unassuming people. Delightful fellows.

It's like all those quiet people, when they do lose their tempers they lose them with a vengeance.

As you yourself have said, what other explanation can there be?' Poirot stared straight ahead of him. 'That is what I ask myself,' he said. 'That is what I never cease to ask myself.

I would like it to be said that I was a good writer of detective and thriller stories.

Sometimes I feel sure he is as mad as a hatter and then, just as he is at his maddest, I find there is a method in his madness.

I have often had occasion to notice how, where a direct question would fail to elicit a response, a false assumption brings instant information in the form of a contradiction.

Everyone likes talking about himself. - Hercule Poirot