Anna Bronsky is a violin teacher at a music-focused high school. Despite the opposition of all the other teachers, Anna drives through the admission of a student, Alexander, in whom she detects a remarkable talent. Committed, she prepares him for the intermediate exam and neglects her family – her son Jonas, whom she brings into competition with her new student, and her husband Philippe. Her colleague Christian, with whom she has an affair, persuades her to join a quintet. When she fails during their joint concert, the pressure mounts and she focuses all her attention on her student Alexander. Come the day of the exam, events take a tragic turn.