Hercule Poirot must unravel a series of near-fatal 'accidents' targeting a young heiress at a seaside resort. While vacationing in Cornwall, the Belgian detective encounters Nick Buckley, a vibrant woman who has narrowly escaped death multiple times in a single week. Poirot assumes the role of protector, investigating the social circle surrounding the End House estate to identify a calculated killer. The narrative unfolds through a classic third-person perspective, emphasizing Poirot's methodical observation and psychological deduction as he navigates a web of deception and hidden motives.

Peril at End House is widely regarded as one of Agatha Christie's most ingenious puzzles, frequently cited for its clever subversion of traditional mystery tropes. Readers and critics often highlight the book's pacing and the surprising nature of the final revelation, which remains a hallmark of Christie's mid-career output. The novel is praised for its effective use of the 'locked-room' style tension despite its open setting, demonstrating the author's command over character psychology. It continues to be studied as a definitive example of the Golden Age detective novel, maintaining its status as a staple for enthusiasts of the genre.