When Ariadne Oliver and her friend, Judith Butler, attend a children's Halloween party in the village of Woodleigh Common, a young girl named Joyce Reynolds boasts of having witnessed a murder from years before. Joyce's story is heard by all the party, including her strange brother Leopold, the impeccable hostess Rowena Drake, her bookish son Edmund, and the local Reverend Cottrell. Mrs Whittaker, the church organist, and Frances Drake, Rowena's feisty daughter, are dismissive of her story, but later that evening Joyce's lifeless body is discovered face-down in the apple-bobbing bucket. At Mrs Oliver's behest, Poirot travels down to Woodleigh Common to investigate the murder. Although the local police and Joyce's stepmother dismiss the dead girl's claim, Poirot takes Joyce's story seriously. Mrs Goodbody, a gossiping charwoman, tells Poirot there have been a number of suspicious deaths in the village in recent years which Joyce could indeed have witnessed, and that old curses still haunt the village - a claim supported by the affable gardener, Michael Garfield. While Poirot is busy piecing together the facts, another child is found drowned in a river. He realizes that he needs to act quickly in order to save Judith's daughter, Miranda, who is also in danger.