The life of young heiress Kim Prescott turns into a nightmare when a strange young man turns up at her villa on the Costa Brava. He claims to be Kim's brother Ward, who was killed in a car crash. Kim is baffled and then shaken when the stranger produces evidence to support his bizarre claim. When a seemingly dependable uncle identifies the intruder as his nephew, Kim becomes frightened. She suspects a plot to drive her insane and collect her father's fortune.