Murder on the Orient Express

Snowbound between Vinkovci and Brod after the Orient Express plows into a drift, detective Hercule Poirot is asked to investigate the murder of an American passenger named Ratchett, stabbed twelve times in his locked compartment overnight. Poirot slowly uncovers Ratchett's real identity: he is Cassetti, a gangster who years earlier kidnapped and murdered a small child named Daisy Armstrong, collected the ransom, and escaped American justice entirely, a crime that also destroyed Daisy's parents and drove an innocent nursemaid to suicide. Working through the sealed carriage's twelve passengers, Poirot finds that every one of them, a countess, a governess, a valet, a conductor, an aging actress, a colonel and more, has a hidden connection to the Armstrong family. His solution is that all twelve stabbed Cassetti together, one wound apiece, a private tribunal carried out because the law had already failed them once. Poirot offers the train's director a simpler, false explanation, an unknown assassin who boarded and vanished, and lets it stand as the official story.

Christie builds the whole book as a closed circle puzzle, everyone a suspect, nobody able to leave the train, and it reads quickly even while asking a reader to track twelve overlapping alibis at once. The solution, when it comes, deliberately breaks the genre's usual promise that justice and law point in the same direction, which is exactly what later critics like Raymond Chandler found implausible and what other readers count as the novel's boldest choice.

Christie based the snowbound setting on her own delayed return from her husband's archaeological dig in Iraq, when floodwaters stopped her train for a day in December 1931, and she drew the Armstrong backstory directly from the real 1932 kidnapping and murder of Charles Lindbergh's infant son, down to the detail of a household employee wrongly suspected and driven to suicide.