The Mysterious Affair at Styles is set in a large, isolated country manor. There are a half-dozen suspects, most of whom are hiding facts about themselves. The book includes maps of the house, the murder scene, and a drawing of a fragment of a will, as well as a number of red herrings and surprise plot twists. It is the first novel by Agatha Christie that introduces Hercule Poirot, Inspector Japp, and Arthur Hastings.