Cariad has been admitted to a psychiatric hospital after crashing her car into that of her lover, Gareth. She needs to talk to him and explain what happened, but is prevented from leaving, locked up and she doesn't understand why. David, a nurse at the hospital is the only one who has any empathy for her. The more he learns more about her, the more he falls for her. His growing interest in her makes him break into her doctor's office and read confidential files to find out what brought her there. David's and Cariad's lives become inextricably linked.