Hercule Poirot investigates a sixteen-year-old cold case to determine if a woman convicted of murdering her husband was truly guilty or the victim of a miscarriage of justice. The protagonist, Hercule Poirot, accepts a request from the daughter of the deceased to re-examine the evidence surrounding the poisoning of a famous painter. He faces the challenge of reconstructing events from long-buried memories, as the five original suspects have moved on with their lives. The narrative framework utilizes a series of retrospective interviews, forcing Poirot to reconcile conflicting testimonies and the fallibility of human recollection.

This novel is widely regarded as one of the most sophisticated entries in the Hercule Poirot series due to its focus on psychological depth rather than mere physical clues. Critics frequently highlight the brilliance of the narrative structure, which allows the reader to piece together the truth alongside the detective through the lens of memory. The book is often cited for its emotional resonance and the clever way it subverts traditional mystery tropes by centering on the subjective nature of truth. Readers consistently praise the intricate character studies of the five suspects, noting that the resolution feels both inevitable and surprising. It remains a definitive example of the golden age of detective fiction, demonstrating the author's mastery of pacing and character motivation.