A young priest named Herbert arrives at a juvenile detention center to perform pastoral duties. From the very beginning, Herbert encounters an impenetrable communication barrier. He finds no support even among the teaching staff, whose gray eminence is the deputy director nicknamed Šéfík. This man is a former boxer and also practices this sport at the institution. If the inmates want to gain any advantages with Šéfík, they have to box. The training also includes fights, where the aggression of the young delinquents is often allowed to run free. Herbert realizes that if he wants to gain a deeper insight into life at the institution, he must accept the rules there. He convinces Šéfík to put him in a fight, and Šéfík deliberately chooses a dangerous opponent for him.