John Medici, better known under his war name of John “des Bandes Noires,” visiting Raphael’s studio in the following of Leo X, saw Emma, the beautiful sister of the painter Caravaggio. John and Emma fall desperately in love with each other, and the girl, forgetting all prudence, accepts an appointment from her lever in her own house. Emma’s brother runs home to revenge the insult, but John makes good his escape, while Emma is sent back to her mother in the City of Caravaggio. Some time afterward John at the head of his army takes the town of Caravaggio by storm, and in the terrible sacking which follows the victory Emma’s mother is slain by the furious soldiery. John succeeds in saving Emma’s life, but the girl, horrified at the sight of the man she holds responsible for the death of her mother, rejects John’s proposal to marry her and seeks for peace and oblivion in a convent. Mortally wounded at the battle of Cassano, John is taken to the palace of the Marquis Gonzaga. On his death-bed he remembers Emma, and sends her an ardent appeal to come and forgive him. The young nun, still dearly loving John, rushes to his side, but only in time to see him die the death of a soldier.