A seemingly innocent Hallowe'en party turns deadly when a young girl who boasted of witnessing a murder is found drowned in an apple-bobbing tub. Ariadne Oliver, a mystery novelist, finds herself at the center of the investigation after the victim's tall tales are suddenly validated by her untimely death. She enlists the help of Hercule Poirot to navigate the social intricacies of Woodleigh Common, where the residents remain skeptical that a crime has even occurred. The narrative follows a classic investigative framework, focusing on the psychological tension between the detective's logic and the community's denial.

This novel is frequently analyzed for its inclusion of Ariadne Oliver, who serves as a meta-fictional surrogate for Christie herself. Readers often note the darker, more cynical tone compared to earlier works in the Poirot series, reflecting the changing social landscape of the era. The mystery is recognized for its focus on the psychological motivations of the village residents rather than purely mechanical puzzles. Critics often highlight the effectiveness of the opening premise, which cleverly uses a child's reputation for lying to obscure a genuine crime. The work remains a staple for those interested in the later evolution of Christie's detective narratives.