When a celebrated American film star buys Gossington Hall on the edge of the quiet village of St Mary Mead, the arrival shakes a community already changing under a new housing estate the locals call the Development. The actress opens the grounds for a charity fete, and among the crowd is a cheerful, talkative local woman who has long admired her. During the reception inside the hall, that woman drinks a cocktail and dies soon after, the poison apparently intended for someone else. Jane Marple, recovering from illness and chafing under the fussy attentions of a live-in companion, follows the investigation from her armchair and through the gossip of friends and neighbours. A Scotland Yard inspector works the official angle while Miss Marple reads the small human details he cannot, sifting old loyalties, a film star's troubled history, and a single overheard remark that nobody else thought worth remembering. As a second death follows, the case turns on a moment of frozen expression seen at the party, an instant when something in the past reached forward into the present. Christie sets a sharp, observant puzzle against the social shift of an English village adjusting to the modern world, and lets her aging detective prove that understanding people matters more than chasing clues. The result is a study of memory, grief, and the cost of a careless act, wrapped inside a classic country mystery.