Rada Heumann, a successful criminal investigator, is searching for a serial killer of children. But that is just one of the secrets revealed in this story by writer Ladislav Fuks. With psychological precision, the author also explores Heumann's family background and his father's despotism, of which the younger of the two sons becomes a victim. Viki, a boy about to graduate from high school, feels humiliated by his father's dictates. He decides to take revenge on his father by questioning his infallibility as a criminal investigator.