Never tell all you know — not even to the person you know best. - Agatha Christie

Looking back, it seems to me extraordinary that we should have contemplated having both a nurse and a servant, but they were considered essentials of life in those days, and were the last things we would have thought of dispensing with. To have committed the extravagance of a car, for instance, would never have entered our minds. Only the rich had cars.

Yes, a private investigator like my Wilbraham Rice. The public have taken very strongly to Wilbraham Rice. He bites his nails and eats a lot of bananas. I don't know why I made him bite his nails to start with — it's really rather disgusting — but there it is. He started by biting his nails, and now he has to do it in every single book. So monotonous.

I like to inquire into everything. Hercule Poirot is a good dog. The good dog follows the scent, and if, regrettably, there is no scent to follow, he noses around — seeking always something that is not very nice.