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. The book includes maps of the house, the murder scene, and a drawing of a fragment of a will. The true first publication of the novel was as a weekly serial in The Times, including the maps of the house and other illustrations included in the book. This novel was one of the first ten books published by Penguin Books when it began in 1935. Styles was well received by reviewers in the UK and the US at initial publication.[4][5][6][7] An analysis in 1990 was positive about the plot, considered the novel one of the few by Christie that is well-anchored in time and place, a story that knows it describes the end of an era, and mentions that the plot is clever. Christie had not mastered cleverness throughout her first novel, as "too many clues tend to cancel each other out"; this was judged a difficulty "which Conan Doyle never satisfactorily overcame, but which Christie would.": 22–23  The story features many of the elements that have become icons of the Golden Age of Detective Fiction, largely due to Christie's influence. It is set in a large, isolated country manor. There are a half-dozen suspects, most of whom are hiding facts about themselves. The plot includes a number of red herrings and surprise twists. The Mysterious Affair at Styles launched Christie's writing career. Christie and her husband subsequently named their house "Styles". Hercule Poirot would go on to become one of the most famous characters in fiction. Decades later, when Christie told the story of Poirot's final case in Curtain, she set that novel at Styles.