Mystery writer Ariadne Oliver has been invited to a Hallowe'en party at Woodleigh Common. One of the other guests is an adolescent girl known for telling tall tales of murder and intrigue — and for being generally unpleasant. But when the girl, Joyce, is found drowned in an apple-bobbing tub, Mrs Oliver wonders after the fictional nature of the girl's claim that she had once witnessed a murder. Which of the party guests wanted to keep her quiet is a question for Ariadne's friend Hercule Poirot. But unmasking a killer this Hallowe'en is not going to be easy — for there isn't a soul in Woodleigh who believes the late little storyteller was actually murdered.