Susan Wheeler is a devoted mother. She would do anything for her three children. She drops them off and picks them up every single day. Until one day when Susan kisses them goodbye and then never comes to pick them up. Susan's mother Mary is worried. Susan is recently divorced and has been finding things hard recently, but she loves her kids - she'd never leave them. Susan's sister Clare is furious. It's just like her to go missing. It's not the first time, either. Susan has always been a troublemaker. Always seeking attention. She knows Susan has been lying to the family for years. And she knows that Susan has been sneaking out of her family home for weeks. As the hours turn into days, even Clare becomes fearful for Susan. And, when Mary discovers Susan's diary, she begins to uncover a dark secret from her childhood. Something no one in the family knew. When the final diary entry leads the police to a man who is discovered dead in a local park, they're left wondering whether Susan has vanished because she is a victim. Or because she is a suspect...