Recently retired, Carole Seddon resides in the seaside hamlet of Fethering, in the cottage she purchased with her ex-husband. There she maintains a quiet and sensible life with the companionship of Gulliver, her Labrador retriever. But everything changes when she and Gulliver find a corpse on the beach while taking their daily constitutional. What's more, there are two wounds on its neck. The body mysteriously disappears and the police dismiss Carole as a befuddled middle-aged woman. She almost starts to believe it herself-until a stranger threatens her to keep quiet or else.Unable to contain her anxiety, Carole confides in her eccentric neighbor, Jude, who suggests that if the police cannot be bothered to catch a killer, maybe they should do it themselves.