The crime novelist Ariadne Oliver summons her old acquaintance Hercule Poirot to Greenshore House, a grand riverside estate in Devon where a summer garden fete is about to take place. Mrs Oliver has been hired to devise a Murder Hunt, a game in which guests follow clues to a staged crime, but a nagging unease has settled over her: small details keep being altered without her knowledge, and she senses the entertainment is being steered toward some real and sinister end. Poirot arrives expecting little more than an afternoon among the marquees and coconut shies. The estate belongs to the wealthy Sir George Stubbs and his much younger, oddly vacant wife Hattie, and the grounds carry the quiet weight of an older family who once held the land. When the local girl chosen to play the pretend victim is discovered genuinely dead inside the boathouse, the game collapses into an actual investigation. Working alongside Inspector Bland and threading through the recollections of the watchful Mrs Folliat, Poirot must read the household, the village, and the layered history of the place itself. This is the original shorter version of a story Christie later reworked into a full-length novel, compact in form yet built on her characteristic interest in concealed pasts, mistaken assumptions, and the small inconsistencies that betray a careful plan.