How can I go on living here and suspecting everybody ? - Agatha Christie

"Poirot," I said. "I have been thinking."
"An admirable exercise my friend. Continue it."

“I like to see an angry Englishman,” said Poirot. “They are very amusing. The more emotional they feel the less command they have of language.”

I have the little idea, my friend, that this is a crime very carefully planned and staged. It is a far-sighted, long-headed crime. It is not — how shall I express it? — a Latin crime. It is a crime that shows traces of a cool, resourceful, deliberate brain — I think an Anglo-Saxon brain.