"The Duenna" is a three-act comic-opera set-in Seville following the story of Don Ferdinand. He is in love with Donna Clara, who is being forced into a nunnery by her cruel father. Don attempts to convince her to run away with him but fails. Meanwhile, his sister, Donna Louisa, is in love with Don Antonio, but her father wants her to marry Isaac Mendoza, who is cunning and greedy.