Alison is lucky and she knows it. She has the life she always craved, including a happy home with Jeff and their brilliant, vivacious teenage daughter, Katherine - the absolute centre of Alison's world. Then a knock at the door ends life as they know it. Fifteen years ago, someone else took Alison's baby from the hospital. And now Alison is facing the unthinkable. The daughter she brought home doesn't belong to her. When you have everything you dreamed of, there is everything to lose.