Poland, summer 1990. Ten-year-old Kai was brought to safety by his mother Minna with Polish friends. His father Arthur wants to kill him because he suspects that Kai has unwholesome tendencies. His sister Maggie fearlessly stands up for Kai and has to protect him from other children. On the way to school there is an argument in which the leader Conradi is seriously injured and Maggie becomes unconscious. Kai swears to his father that he will never tell Maggie the truth about himself. A scary man (Liliom Lewald) also knows that the introverted boy is special. He visits Kai and offers him to live with his "real" family.

Kai can't live with his guilt and wants to shoot himself. Maggie saves him at the last second. She wants to give her brother the chance to work together to find those behind the unimaginable acts and to make amends for something like that. In order to stop the series of crimes, the ex-policewoman goes in search of the key figure: the "Great Hunter". A trail leads to 1947. At that time, two men were suspected of having committed gruesome murders. One of the suspects was Maggie's now over 90-year-old father Arthur, the other disappeared a long time ago. Together with Roland, Maggie uncovers a disturbing family secret.