Palace of the King of Naples. Night. Don Juan comes from the Duchess Isabella, who takes him for her beloved Duke Octavio. She wants to light a candle, but don Juan stops her. Isabella suddenly realizes that with her was not Octavio, and calls for help. The King of Naples comes to the noise and orders the guard to seize the Don
Juan and Isabel. He instructs the Spanish ambassador, Don Pedro Tenorio, to figure out what happened and leaves. Don Pedro orders to take Isabella away. When Don Pedro and don Juan remain face-to-face, don Juan tells how he tricked into Isabella and mastered it. Don Juan is the nephew of Don Pedro, and his uncle willy-nilly has to cover him
The tricks. Fearing monarchy anger, he sends don Juan to Milan and promises to inform his nephew about the consequences of his deception. Don Pedro reports to the King of Naples that the man the guard grabbed jumped from the balcony and fled, and the lady, who turned out to be the Duchess of Isabella, claims that the Duke of Octavio appeared to her at night and cunningly mastered her. The king orders to quit
Isabel in prison, and Octavio grab and forcibly marry Isabella. Don Pedro and the guards come to the house of Octavio. Don Pedro on behalf of the king accuses him of having dishonored Isabel, who believed his promises. Octavio, learning about the infidelity of his beloved, comes to despair and decides to flee secretly to Spain. Don Juan, instead of going to
Milan, too, sails to Spain. The young fisherman Tisbeia sits on the seashore near Tarragona and fish. All her friends are in love, she does not know the torments of love, and she rejoices that neither passion, nor jealousy does not poison her life. Suddenly there is a cry: “Save! Ton!”, And soon on the land are selected two men: it is don Juan and his servant Catalinon. Don Juan saved the drowning servant, but, having left on land, collapsed unconscious.