Until he was 11, Detlef Kammrath (René Siodla) had a carefree childhood. But now his parents have decided to go their separate ways and divorce - a catastrophe for the boy. The court awards custody to his mother (Karin Schröder), but Detlef harshly rejects his mother's new partner (Gerd Grasse). He sees him as the person responsible for his unhappiness. Hoping to improve the family atmosphere, his mother forbids the boy from meeting his biological father; this leads to Detlef's absolute despair, and he becomes a "case" for child welfare services.
