When Lydia was a teenager, she made a decision that ruined her family's life. They've spent the last thirty years living with the consequences and doing their best to pretend it never happened. Lydia's husband, the gorgeous and reliable Mark, and her two teenage children know nothing about that summer back in 1982. And that's the way Lydia wants it to stay. The opportunity to come clean is long gone and now it's not the lie that matters, it's the betrayal of hiding the truth for so long. When someone from the past turns up as a parent at the school gates, Lydia feels the life she has worked so hard to build slipping through her fingers. The more desperate she becomes to safeguard her family, the more erratic her behaviour becomes. But when the happiness of her own teenage son, Jamie, hangs in the balance, Lydia is forced to make some impossible decisions. Can she protect him and still keep her own secret -- and if she doesn't, will her marriage and family survive?