 Cosmo, fearful of Lorenzo as the Duke's favorite, surrenders his interest in Oriana to another nobleman, Pisano; Pisano, in turn, breaks his engagement with Amidea and wins the consent of Oriana's mother.Lorenzo manipulates Sciarrha's anger at Pisano's treatment of Amidea; Sciarrha kills Pisano on the morning of his marriage, and Lorenzo sets him up to murder the Duke as well.Sciarrha tells Amidea that she will have to yield to the Duke, if he does not kill her; playing for time, Amidea suggests that she will satisfy the Duke — and Sciarrha stabs her.