When the glamorous Arlena Stuart is found strangled on a secluded beach, Hercule Poirot must untangle a web of jealousy and hidden motives among the guests of a luxury island resort. Poirot arrives at the seaside retreat to find the atmosphere thick with simmering resentment and illicit attraction, forcing him to look past the obvious suspects. As he navigates the social dynamics of the vacationers, he must determine if the murder was a spontaneous act of passion or a calculated execution. The narrative follows a classic whodunit structure, relying on Poirot's meticulous observation and psychological insight to expose the truth hidden beneath the surface of a seemingly idyllic holiday.

This novel is widely regarded as one of the most polished examples of Christie's mastery of the closed-circle mystery. Readers and critics frequently highlight the effectiveness of the isolated island setting in heightening the tension among the guests. The characterization of the victim and the suspects is often noted for its sharp, cynical edge, which contrasts effectively with the sunny, vacation-like backdrop. The resolution is frequently cited for its clever subversion of expectations, solidifying the book's status as a staple of the detective genre.