When Charlotte Daly wins a scholarship to the prestigious St Thomas’s school, her mother Ali - who has struggled to bring Charlotte up as a single mum - is so proud. She hopes this opportunity will mean a better life for her clever, brilliant daughter. Ali worries, however, that Charlotte is having a hard time fitting in with her new, wealthy peers. So when Charlotte is invited to a sixteenth birthday party by popular boy Ollie, Ali pushes her to go, hopeful that she'll finally make some friends. Just before midnight, Charlotte calls Ali to come pick her up from the party. She’s shaking and silent: it's obvious something has happened but she won’t say what. It's only the next day, when Ali is at work, that she learns a teenage boy has been seriously injured. Then the police turn up at their house, wanting to question Charlotte about the events of that night. People are pointing the blame at Charlotte, saying the injured boy was last seen talking to her, before he was found unconscious in the pool. As the investigation deepens, Ali finds that everyone has their own agenda and people will stop at nothing to protect their children - especially wealthy people. Only Charlotte knows the truth about what happened that night. Can Ali get her to tell the truth before it's too late?