Two anglers discover a pile of corpses in a field near the polish border. The unimaginably high number of skeletons and animal carcasses leads the police to suspect a serial killer who has apparently been killing undetected for decades. Local detective inspector Roland Voit (Felix Kramer) is assigned to support the large LKA contingent in the Oderbruch. His former childhood sweetheart, former policewoman Maggie Kring (Karoline Schuch), is also called to her home town of Krewlow. After years of silence, Maggie and Roland are anything but impartial. Maggie is following her own investigations. She left Krewlow in 1997 after her brother became a victim of the historic Oder flood at the age of 17. The ex-policewoman doubts everything she knows - including the death of her brother Kai.

Poland, summer 1990: ten-year-old Kai (Edgar Emil Garde) has been taken to safety by his mother Minna (Uta Janietz) to stay with Polish friends. His father Arthur (Stefan Weinert) wants to kill him because he suspects that Kai has a sinister tendency. His sister Maggie (Alix Heyblom) 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 (Bennet Mai) 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 (Liliom Lewald) also knows that the introverted boy is special. He seeks Kai out and offers him the chance to live with his "real" family.