Carla Nowak (29), a young physical education and mathematics teacher, starts her first job at a grammar school. Carla stands out among the new employees because of her idealism. However, a series of unsolved thefts has strained the mood of the teaching staff. When a Turkish student is suspected and brought before the strict headmistress in an unseemly manner, Carla decides to get to the bottom of things. With the help of a hidden camera, she convicts the thief: to her surprise, the academy's inconspicuous secretary, Friederike Kuhn (47), appears to be behind the theft. But the discovery of the crime puts Carla in an unsolvable dilemma: Friederike Kuhn is also the mother of 13-year-old Oskar Kuhn, Carla's most talented student. As a result, Carla loses control of the situation more and more. On the one hand, she is isolated and helpless at the academy. On the other hand, Carla is responsible for the psychological burden of Oskar, who is now also the "son of a thief" in the eyes of the children. The educational institution has a simple solution to this situation: Oskar will be transferred to another school. Undeterred, Oscar seeks to contact the school newspaper and make sure the story - from his mother's point of view - reaches the public. As the school newspaper begins to circulate, a discussion about truth and justice breaks out.