Bianca e Fernando
Fernando returns to Agrigento in disguise to avenge his father, Duke Carlo, whom he believes dead and whose throne was seized by Filippo. His sister Bianca, unaware of Filippo’s crimes, is preparing to marry him and at first fails to recognize Fernando. The siblings reunite, expose Filippo, and free Carlo; when Filippo threatens Bianca’s infant son, Fernando’s allies disarm him and the tyrant is overthrown.