A series of minor thefts has plagued the school, and following an unsuccessful and poorly managed search of the classrooms, the optimistic and seemingly inexperienced teacher, Miss Novak (played by Leonie Benesch), decides to set up a video recording in hopes of discovering who is responsible. She appears to identify someone stealing from her belongings, prompting headmaster Böhm (Anne-Katrin Gummich) to attempt to manage a situation that quickly escalates and exposes a considerable amount of negativity affecting not only the teacher but also relationships across all levels of the school—along with an unproductive system of bureaucracy. A tense confrontation arises, approaching criminal activity, as opposing sides are established both within and outside the staff room. I struggled to accept some aspects of the unfolding events. While the acting is strong and the direction keeps things moving at a brisk pace, particularly Leonard Stettnisch’s convincing performance as the student and antagonist Oskar, much of what unfolds felt far-fetched. Any safeguards intended for teachers and students seem to have been disregarded in favor of dramatic effect, and the lack of police or experienced investigators seemed unrealistic as events progressed toward an ending that left me feeling somewhat disappointed. It's certainly engaging and worth seeing—but its believability is questionable.

Source on TMDB