Anna has always believed that her mother, Debbie, died 30 years ago on the night she disappeared. But when her father gets a strange note, she realises that she's never been told the full story of what happened that night on the cliff. Confused and upset, Anna turns to her husband Jack -- but when she finds a love letter from another woman in his wallet, she realises there's no-one left to help her, least of all her family. And then a body is found...