The Doctor tells the Duke that he has successfully poisoned Hippolito (a lie). The Duke rewards the Doctor's supposed treachery by banishing him from court—a measure taken to ensure that the Doctor won't use his poisoning skills against the Duke himself some day. The Duke exits and Hippolito enters. The Doctor reveals the details of Infelice's faked death and the Duke's murderous plots. Hippolito says he will go to Bergamo to meet Infelice immediately. The Doctor tells him that Infelice knows all, and has already made arrangements to meet him on the following morning at Bethlem Monastery, where the couple will be married by a priest named Father Anslemo. Hippolito praises the Doctor and exits.