Hallowe'en Party is a detective novel written by the British author Agatha Christie in 1969. It is a novel in which Hercule Poriot, the Belgian detective, is the protagonist.
The novel has been adapted as a BBC radio play and as a graphic novel which was published in 2008. Hallowe'en Party was adapted for television as an episode of the British detective series Agatha Christie's Poirot in 2010.
The story begins when Joyce Reynolds, an unpopular 13-year-old girl, tells everyone who comes to the Halloween party at her house, including Mrs. Ariadne Oliver, that she witnessed a murder. None of the guests believe her, and Joyce runs away in anger and dismay. Joyce is later found dead. Somebody drowned her in an apple bobbing tub. Mrs. Oliver rushes to her detective friend Hercule Poriot. Poriot reveals the astonishing truth of what took place on that horrible night.