Poland, summer 1990: ten-year-old Kai has been taken to safety by his mother Minna to stay with Polish friends. His father Arthur wants to kill him because he suspects that Kai has a sinister tendency. His sister Maggie fearlessly stands up for Kai and has to protect him from other children. A fight breaks out on the way to school, in which the leader Conradi is seriously injured and Maggie is knocked unconscious. Kai swears to his father that he will never tell Maggie the truth about himself. A sinister man also knows that the introverted boy is special. He seeks Kai out and offers him the chance to live with his "real" family.