 In this obvious forerunner to _Hets (1944)_ (qv),  Stig Järrel  (qv) plays the mentally disturbed latin teacher Birger Sjögren at Ringsala boarding school. A series of mysterious fires has taken place around the school the last few months. One of the students has seen Sjögren setting fire to a barn. But can he convince the trusted biology teacher Nordmark, expert of the criminal mind?