The rebellious socialist Knut undergoes a mental examination after he assaulted a stranger in the street. The psychologist is looking to track Knuts aggression from childhood experiences, while Knut himself sees it as a natural reaction to the class society's oppression. Intensely debated film depicting how the Swedish mental health services perception and view socially deviant or so-called sociopaths. Lars Lennart Forsberg's debut work that won Guldbagge for the 1969 best Swedish film.