One morning Caitlin Eckhart receives a phone call that changes her life forever - her much-loved six-year-old stepson Geordie has disappeared from school. It soon becomes clear that someone must have deliberately taken him. Distraught, Caitlin and her husband, Noah, make an anguished public appeal for his return. But Caitlin has a secret from her past that is about to catch up with her, and as Geordie's continued absence brings her relationship with Noah to breaking point, she stands to lose everything that she loves.