The Mysterious Affair at Styles is the first detective novel by British writer Agatha Christie, introducing her fictional detective Hercule Poirot. It was written in the middle of the First World War, in 1916, and first published by John Lane in the United States in October 1920 and in the United Kingdom by The Bodley Head (John Lane's UK company) on 21 January 1921. Styles introduced Poirot, Inspector (later, Chief Inspector) Japp, and Arthur Hastings. Poirot, a Belgian refugee of the Great War, is settling in England near the home of Emily Inglethorp, who helped him to his new life. His friend Hastings arrives as a guest at her home. When Mrs Inglethorp is murdered, Poirot uses his detective skills to solve the mystery.