1982. Thirteen-year-old Ewan Fraser is sent to the remote island of Barra, off Scotland's west coast, to stay with his aunt and uncle. Resigned to a monotonous summer of boredom, he is befriended by local girl Laura Robertson; together they explore the golden beaches and rocky coves of the idyllic island. But a dark secret that connects Laura to the mysterious outcast Mhairi Matheson and her son, Billy, is hidden beneath the tranquil surface... A secret that threatens to tear the small community apart. Forty years later, Ewan returns to confront the truth about the formative summer of his adolescence, and finally learn the truth about Laura and the boy from Barra.