While vacationing on the Cornish coast, Hercule Poirot and Captain Hastings encounter the charming and seemingly carefree Magdala "Nick" Buckley, owner of the picturesque End House. Poirot's sharp instincts are immediately piqued when he learns of the improbable series of "accidents" Nick has recently survived, including malfunctioning car brakes, a falling boulder, and a near-miss with an oil painting. A bullet hole discovered in her sun hat confirms Poirot's suspicion: these are no mere coincidences, but deliberate attempts on her life. As Poirot endeavors to protect Nick, he uncovers a complex web of secrets, hidden motives, and potential suspects among her friends and family. The tranquil facade of End House soon gives way to a darker reality, compelling the detective to unravel a cunning plot before another life is claimed.