Conor is a 13-year-old boy who lives in the real world - a place where boys bully him at school and his mother slowly wastes away from terminal cancer. Although Conor believes he is alone, his heartbreak doesn't go unheard: There's a monster in the world that comes when you call it. It hears Conor's call and responds in the form of an ancient tree. It asks very little: Conor must listen to the monster's three stories and then tell his story. The monster insists that if Conor complies, it will help him. Will the monster help or hurt Conor.