While enjoying a vacation at an exclusive resort on the Cornish coast, Poirot and Hastings meet beautiful young heiress Magdala Buckley. Known to her friends as Nick, she confides to them that she has recently survived several events that might have taken her life: a heavy-framed picture dropping on her head, a boulder falling off a cliff, and failed brakes. When Poirot notices a bullet hole in her hat, they put her under their protection and discover that her dead fiance, a noted aviator killed in a tragic accident, had named her as heir in his will. In the interim, his wealthy uncle is found to have died, making her the unexpected beneficiary of a great fortune. Poirot realizes this inheritance is the motive for continued attempts on her life, and in his quest for the the truth, he uncovers a tangled web of greed, forgery, drug addiction, fraud, poison, and murder.