A stunning and timely new novel from the bestselling author of The Boy in the Striped Pyjamas. Sam is a bit of a loner. But his older brother Jason has always been there for him. Then Jason calls his family together to tell them that he's been struggling with a secret for a long time. What do you do when your brother says he's not your brother at all? That he thinks he's actually...your sister? 10+ A life-changing decision. A family turned upside down.