A festive family reunion turns lethal when the patriarch of the Lee family is found murdered in his locked room, forcing Hercule Poirot to navigate a web of long-standing grievances and hidden motives. The victim, Simeon Lee, has summoned his estranged sons home for the holidays only to taunt them with threats of disinheritance and verbal abuse. Poirot, present as a guest, must sift through the conflicting testimonies of the family members, each of whom possesses a distinct reason to desire the old man's demise. The narrative operates as a classic closed-circle mystery, relying on Poirot's meticulous observation of human behavior and physical clues to dismantle the suspects' carefully constructed alibis.

This novel is widely regarded as a quintessential example of the classic golden age detective story, praised for its intricate plotting and effective use of the locked-room trope. Readers often highlight the sharp characterization of the dysfunctional Lee family, which provides a compelling emotional backdrop to the central puzzle. The pacing is frequently noted for its steady build toward a logical and satisfying resolution that showcases Poirot's analytical prowess. It remains a staple of the genre, frequently cited for its ability to balance a grim premise with the traditional atmosphere of a holiday mystery.