At a children's Hallowe'en party in the quiet English village of Woodleigh Common, a boastful thirteen-year-old named Joyce Reynolds announces that she once witnessed a murder. The adults dismiss her as a fanciful attention-seeker, and the games go on. Before the evening ends, Joyce is found drowned in the tub set out for bobbing apples. Crime novelist Ariadne Oliver, a guest at the party, is shaken enough to summon her old friend Hercule Poirot. Poirot arrives convinced that the girl was killed because her claim, however unreliable, brushed against a truth someone needed buried. He works through the village's recent history, calling on a retired police superintendent for a list of old, half-forgotten deaths that might be the murder Joyce remembered. As Poirot questions schoolteachers, gardeners, and grieving families, he learns that small communities keep their secrets close, and that a careless boast can be more dangerous than any threat. The investigation turns on questions of inheritance, beauty, and the way children see more than adults credit them for. Christie writes with the unease of her later years, setting cozy village ritual against genuine menace and the vulnerability of the young. Methodical and observant, Poirot follows the buried wrong toward its source, knowing that the killer is still moving among the people he interviews each day.