Dame Agatha Mary Clarissa Christie wrote 66 detective novels and 14 short-story collections, and is the best-selling novelist of all time, with more than two billion copies sold and more translations than any other individual author. She created Hercule Poirot and Miss Marple, wrote Murder on the Orient Express and And Then There Were None, and her play The Mousetrap has run longer than any other in the world. She composed much of her work — particularly dialogue — in her head before ever putting it on paper, which is exactly why the sink-and-bathtub anecdotes ring true.