In 1900 in Rome, the poor carpenter Francesco, by a twist of fate, is recognized component of a noble family in the process of decay. Francesco knows the cynical and ruthless Prince Torquato Terenzi, disappointed by life and progress, and also falls in love with the beautiful Duchess Elisa. When Prince Terenzi dies, Francesco realizes that he's not enriched for nothing with the inheritance, because the noble family is broke; so he enlistes himself for the war in Libya, but quickly returnes to Italy, disgusted by the atrocities of the fighting. His dream is to be a singer, and so he goes to America with the Duchess Elisa.
On entering her bathroom, Luisa finds a naked man showering. She calls the police at once and the man is arrested. At the police station Alberto, a psychiatrist, recognizes the man: he is Paolo, Luisa's husband. Alberto offers to help Paolo, but when the two men arrive at his home, Paolo still in his bathrobe, Luisa hugs Alberto and calls him Paolo. The two men try everything they think of to help Luisa regain her memory until the last (but not too unexpected) surprise.
Two minstrels singing for their supper in Rome discover they've both been lovers to the same woman, and one of them is the father of her infant son; a privilege neither is willing to concede.
