A judge investigates the death of a young woman, possibly a murder. He suspects a famous industry tycoon with high political connections. But to what extent do the latter's lies and frauds influence the magistrate's opinion?

An obscure Italian magistrate suspects that a well-known industrialist commited murder, and decides to investigate him, and bring him to court, whatever it takes. But - will the magistrate have it in him to go against impossible odds, in the name of the Italian people he represents?—Artemis-9

An inflexible judge, politically inclined to the Left, Mariano Bonifazi (Ugo Tognazzi) investigates the cause of the death of a young woman, Silvana Lazzorini (Edy Galleani). The autopsy reveals that the cause of death is to be ascribed to an overdose of a drug which is only available on the German market. Lazzorini's body shows bruises which could possibly infer she was beaten prior to her death. Investigating the woman's whereabouts, Bonifazi discovers the woman worked as a socialite and as an escort, often attending parties and being hired by an industry tycoon, Lorenzo Santonocito (Vittorio Gassman)to entertain his party and business guests. The judge knows well that Santonocito is a crook who has high political protection and who frauds the law in all possible ways and always ends up unpunished. Santonocito starts to feel afraid as he has got no alibi on the night of the murder and because he knows that Bonifazi is convinced of his responsibility. Nevertheless, he protests his innocence and tries to fabricate an alibi for that night, showing his ruthlessness and determination to achieve his purpose. He finally succeeds in fabricating an alibi with the help of a financially troubled friend but Bonifazi succeeds in demonstrating the fraud and issues an arrest warrant for Santonocito in order to bring him to trial. While Bonifazi is working on the warrants, the Police bring him Lazzorini's personal diary which brings in new elements. Now Bonifazi's conscience has the final word.—Cesare67