Tai and Jannik are outsiders at their school who are also bullied by their classmates. They manage to lock their school principal, Mr. Lamprecht, in his apartment and torture him via a PC. What starts as a prank gradually escalates. In his attempts to find out who his kidnappers are, Lamprecht reports more and more about his past and his private life, including: about his failed marriage and his problematic actions surrounding the suicide of a student. When he finally wants to commit suicide himself, Jannik frees him. Until the end, Lamprecht doesn't know who kidnapped him and can't prove the kidnapping itself.
—Wikipedia