The background of this drama about a father-and-son relationship is today's terrorism in Italy. It is a highly dramatic tale giving psychological insight into its characters and a polemical assessment of the deep pressures in Italian society.

Fifteen-year-old Emilio (Fausto Rossi) wonders why his father, a university professor (Jean-Louis Trintignant) often invites one of his students with his girlfriend for weekends to the family's country house.

The son takes photographs of his father with his visitors. When one day he witnesses a shoot-out between the student (who is obviously a terrorist) and two policemen, Emilio informs on him. His father is called in for questioning, but is later released. His attempt to talk to the boy fails, as his son insists he was doing his duty. Some time later, Emilio sees the girl visiting the professor again.

The boy takes pictures of them together, intending to turn in the girl. All the sudden attempts by the father to show more concern for the boy , and to make up for years of neglect, come too late.