Karel Doležal, insurance clerk and exemplary father of a family, leaves for a business trip with his secretary Vlasta. After spending the night together, they both return home. However, thanks to a small moment of inattention, they run over the boys. Karel runs away from the scene of the crime. He won't tell anyone what happened. Then when he reads in the newspaper that the boy did not survive the accident, he begins to feel guilty. He confides in his wife about the accident, not the infidelity. Their son Jirka overhears everything. His father has always been his role model, and that's why he doesn't want to accept his guilt.

A new teacher with high standards and a strong sense of duty replaces an easy grader. Once bad grades begin to pile up, a product of his predecessor's subservience to the system, the new teacher has to stand up for himself and his students.