When a brilliant scientist is poisoned during a tense attempt to recover a stolen explosive formula, Hercule Poirot must identify the killer among a house full of suspects. Poirot arrives at the Amory estate to find a family fractured by secrets, greed, and hidden agendas. As the investigation unfolds, he navigates the claustrophobic environment of a locked-room scenario where every guest possesses a motive for murder. The narrative follows the classic detective framework, emphasizing deductive reasoning and the careful observation of human behavior under pressure.

This novelization by Charles Osborne successfully translates Agatha Christie's original stage play into a prose format that retains the characteristic wit and precision of the Poirot canon. Readers often appreciate how the adaptation preserves the theatrical tension of the locked-room mystery while allowing for deeper insight into the characters' internal states. The narrative structure remains faithful to the source material, ensuring that the pacing feels consistent with Christie's traditional detective stories. While some purists may prefer the original play, the consensus suggests that this version provides an accessible and engaging experience for fans of classic crime fiction.