During preparations for a children’s Hallowe’en party, thirteen-year-old Joyce boasts that she once witnessed a murder. Before the evening ends she is found drowned in an apple-bobbing tub, and Ariadne Oliver asks Poirot to discover which unresolved death in the village may have prompted the killing.
Poirot revisits disappearances, disputed wills and local tragedies while considering how adults dismiss children who are boastful or inconvenient. The post-war village is less stable than St Mary Mead, and the case examines neglected young people, changing authority and the danger created when an old crime survives only in uncertain memory.