Synopsis: Romantic tragedy. The Duke of Mantua was held captive by the Moors for 5 years, until being rescued by the courtesan Magdalen. After returning home, he fell into a deep depression in which he forgets the woman who saved him, and whom he loves. To encourage his marriage to the Princess Hipppolyta, his uncle summons the "young boy" Diego to sing to Hippolyta wooing her for the Duke, which only succeeds in having Hippolyta attracting the Princess's affections for "him". Diego, of course, is Magdalen in disguise. And when Diego sings for the Duke and Hippolyta on their wedding day, realizing that she will never regain her past with the Duke, Diego/Magdalen throws herself into the lake and drowns. At that point, the Duke regains his memory, albeit too late.