Dame Agatha Mary Clarissa Christie, Lady Mallowan, DBE (née Miller; 15 September 1890 – 12 January 1976) was an English writer. She is known for her 66 detective novels and 14 short story collections, particularly those revolving around her fictional detectives Hercule Poirot and Miss Marple. Christie also wrote the world's longest-running play, a murder mystery, The Mousetrap, and, under the pen name Mary Westmacott, six romances. In 1971 she was appointed a Dame Commander of the Order of the British Empire (DBE) for her contribution to literature. Christie was born into a wealthy upper-middle-class family in Torquay, Devon. Before marrying and starting a family in London, she had served in a Devon hospital during the First World War, tending to troops coming back from the trenches. She was initially an unsuccessful writer with six consecutive rejections,[4] but this changed when The Mysterious Affair at Styles, featuring Hercule Poirot, was published in 1920.[5] During the Second World War, she worked as a pharmacy assistant at University College Hospital, London, acquiring a good knowledge of poisons which feature in many of her novels.

Guinness World Records lists Christie as the best-selling novelist of all time. Her novels have sold roughly 2 billion copies, and her estate claims that her works come third in the rankings of the world's most- widely published books, behind only Shakespeare's works and the Bible. According to Index Translationum, she remains the most- translated individual author, having been translated into at least 103 languages.Christie's stage play The Mousetrap holds the world record for longest initial run. It opened at the Ambassadors Theatre in the West End on 25 November 1952, and as of April 2019 is still running after more than 27,000 performances. In 1955, Christie was the first recipient of the Mystery Writers of America's highest honour, the Grand Master Award. Most of her books and short stories have been adapted for television, radio, video games and comics, and more than thirty feature films have been based on her work.

Murder on the Orient Express is a detective novel by British writer Agatha Christie featuring the Belgian detective Hercule Poirot. It was first published in the United Kingdom by the Collins Crime Club on 1 January The elegant train of the 1930s, the Orient Express, is stopped by heavy snowfall, with many passengers. A murder is discovered, and Poirot's trip home to London from the Middle East is interrupted to solve the murder. In December 2014, the novel was included in Entertainment Weekly's list of the Nine Great Christie Novels.

References and allusions he kidnapping and murder of Charles Lindbergh's son in 1932 inspired that element in Christie's novel two years later. The film used many elements of the real life case: a young child, firstborn of the family, was kidnapped for ransom directly from the crib, the parents were famous, the father was a well known pilot and the mother pregnant, and the ransom was paid but the child found dead soon after. An innocent, but perhaps loose-lipped, maid employed by Lindbergh's parents was suspected of involvement in the crime. After being harshly interrogated by police, she committed suicide. Two less notable events helped inspire her novel: Agatha Christie's first journey on the Orient Express in late 1928, and a blizzard near Cherkeskoy, Turkey, that marooned an Orient Express for six days just a few months later, in February Flooding from rainfall that washed sections of track away in December 1931 halted Christie's return from her husband's archaeological dig at Nineveh aboard an Orient Express for twenty four hours. Her authorised biography details that event in a complete quotation of a letter to her husband, which describes several passengers on her train who inspired both the plot and the characters in her novel, including an American, Mrs. Hilton, who inspired Mrs. Hubbard.