Agatha Christie her service in September 1918. After the war, Agatha and Archie Christie settled in a flat at 5 Northwick Terrace in St. John's Wood, northwest London. Christie had long been a fan of detective novels, having enjoyed Wilkie Collins's "The Woman in White" and "The Moonstone", as well as Sir Arthur Conan Doyle's early Sherlock Holmes stories. She wrote her own detective novel, "The Mysterious Affair at Styles", featuring Hercule Poirot, a former Belgian police officer noted for his twirly large "magnificent moustaches" and egg-shaped head. Poirot had taken refuge in Britain after Germany invaded Belgium. Christie's inspiration for the
Hercule Poirot and English, Poirot is also fluent in German. Gustave[...] was not a policeman. I have dealt with policemen all my life and I "know". He could pass as a detective to an outsider but not to a man who was a policeman himself. Hercule Poirot was active in the Brussels police force by 1893. Very little mention is made about this part of his life, but in "The Nemean Lion" (1939) Poirot refers to a Belgian case of his in which "a wealthy soap manufacturer[...] poisoned his wife in order to be free to marry his secretary". As Poirot was