[2][3][1] Commissioner Mauro Mariani is known for his severity towards criminals and for his habit of acting on his own, which cost him the transition from Dr. Crivelli's mobile team to a simple neighborhood police station, where he can assist him.

One day, while Mariani is with his wife Vera and his son Claudio, from whom he usually lives separated, a boy named Sergio Conforti bursts into his office and, holding an officer under the gun, forces him to call the absent commissioner because he wants to kill, considering him guilty of his father's suicide, arrested by Mariani two years earlier.

Initially Mariani does not understand the message; then, reconstructing the arrest of Sergio's father, he ends up remembering.

Maurizio Merli later described the film as "a movie made out of nothing" and that the director Stelvio Massi was not happy with the results.

[1] Il comissario di ferro was distributed theatrically in Italy by Belma on 7 December 1978.