After a year in Europe, the young Samantha, daughter of a prominent American politician returns home. She is convinced that she was sent home because she was romantically linked to Nat Brook, a black revolutionary. After one of his numerous protests against violence, Nat feels he is being followed by two men sent by her father . But in the duel that follows the young revolutionary knocks out the two stalkers . Then he breaks it off with Samantha because, beyond the his feelings for her, she is starting to feel like a burden to his protesting activities.

A young peasant, Aldo Contini, come to Rome in search of a job. In order to observe two women who are sunbathing on a terrace, he climbs up to a roof, not knowing that he is on the roof of a palace, in which has been killed a little girl. Forced to escape, on his own from the moment in which someone discovers the corpse, he is mistaken for the assassin and only the providential participation of a policeman succeeds in saving him from the furious vengeance of an angry mob. In possession of some clues, he is subjected to a brutal interrogation by the police, during which Aldo, after having uselessly protested his innocence of the crime, ends up confessing to the crime in front of the enquirers.