The Mystery of the Blue Train is a work of detective fiction by British writer Agatha Christie, first published in the United Kingdom by William Collins & Sons on 29 March 1928 and in the United States by Dodd, Mead and Company later in the same year. The UK edition retailed at seven shillings and sixpence (7/6) and the US edition at $2.00. The book features her detective Hercule Poirot. The novel concerns the murder of an American heiress on Le Train Bleu, the titular "Blue Train". As a work published in 1928, the novel will enter the public domain in the United States on January 1, 2024. Source: Wikipedia (en)