In the late 70s, young Petra Grust begins teaching at the progressive Odenwald School. She is flattered by the trust placed in her by its widely respected headmaster Simon Pistorius. But gradually certain incidents at the boarding school begin to unsettle her. Petra then realizes that Pistorius is abusing Frank, a 13-year-old. When Frank is told that he has to spend school holidays with Pistorius, he tries to commit suicide. Petra tells Frank's father (the chairman of the school's governing body) but he believes Pistorius instead of his own son. Petra fails to convince people of the man's true nature. 30 years later, Frank goes to Petra, who has long since left the school and has stopped teaching altogether. He has never been able to speak about what happened but now, after the suicide of another pupil, he is no longer willing to remain silent. He wants Petra to bear witness at the school's forthcoming anniversary celebrations.