Phillippo Caraffa, Duke of Pavia, has accidentally caught sight of a beautiful young woman named Bianca, the daughter of a Milanese gentleman, while he was hunting. Caraffa falls in love with her, and marries her. Yet the Duke's close friend Fernando also falls in love with the new duchess; she rejects him at first, but eventually acknowledges similar feelings for him. Fiormonda, the widowed sister of Caraffa, has long suffered an unrequited passion for Fernando; she perceives the attraction between Fernando and Bianca, and informs her brother. Through her sycophant, the Machiavellian villain D'Avolos, she works upon her brother's feelings of jealousy and outrage until he precipitates the final scene's violence that leaves both lovers dead ("lovers," though the affair between Fernando and Bianca is in fact never consummated physically). Caraffa joins them by taking his own life.