Act I
At the seaside palace of the bey Mustafa in Algiers, his wife Elvira, complains that her husband no longer loves her. Mustafa bursts in, sends Elvira away and says that he has tired of his wife and will give her to Lindoro, a young Italian at the court, to marry. He then he orders Haly to provide an Italian woman for himself, someone more interesting than the girls in his harem. Lindoro longs for his own sweetheart, Isabella, whom he lost when pirates captured him. Mustafa tells him he can have Elvira.
Haly's pirates catch Isabella who arrives on shore, lamenting the cruelty of a fate that has interrupted her quest to find her lost lover Lindoro. Though in danger, she is confident of her skill in taming men. As the pirates seize Taddeo, an aging admirer of Isabella, and attempt to sell him into slavery, he claims he is Isabella's uncle and cannot leave her.
Mustafa promises Lindoro he may return to Italy if he will take Elvira and he agrees, making it clear he might not marry Elvira until after they reach Italy. Elvira, however, loves her husband and sees no advantage in aiding Lindoro's escape, yet he tells her she has no choice but to leave her heartless husband.
Mustafa welcomes Isabella with pomp and circumstance. As she seemingly throws herself on his mercy, the jealous Taddeo starts to make a scene and is saved only when she declares that he is her uncle. As Elvira and Lindoro, come to say good-bye, Lindoro and Isabella are stunned to recognize each other. To prevent Lindoro's departure, Isabella insists that Mustafa cannot banish his wife, adding that Lindoro must stay as her own personal servant.
Act II
Mustafa declares he will visit Isabella in her room for coffee. She is however upset because Lindoro agreed to escape with Elvira. Lindoro though reassures her of his loyalty. Mustafa reappears, followed by attendants with the terrified Taddeo, who is to be honored as the bey's Kaimakan, or personal bodyguard, in exchange for helping secure Isabella's affections.
In her apartment, Isabella prepares for Mustafa’s visit, telling Elvira that the way to keep her husband is to be more assertive. To make Mustafa impatient, Isabella keeps him waiting, as her "servant" Lindoro acts as go-between. At length she presents herself to the bey, who introduces Taddeo as his Kaimakan. Mustafa sneezes -- a signal for Taddeo to leave, however Taddeo stays, and Isabella invites Elvira to stay for coffee, to Mustafa’s displeasure. When Isabella insists that he treat his wife gently, Mustafa bursts out in annoyance.
Haly predicts that his master is no match for an Italian woman. As Lindoro and Taddeo plan their escape, Taddeo says he is Isabella's true love. Lindoro is amused but realizes he needs Taddeo's help in dealing with Mustafa, who enters, still furious. Lindoro says Isabella actually cares very much for the bey and wants him to prove his worthiness by entering the Italian order of Pappataci. Believing this to be an honor, Mustafa asks what he has to do. Lindoro explains that he simply has to eat, drink and sleep as much as he wants, being oblivious to anything around him.
Isabella prepares for the initiation as Lindoro reminds Mustafa of the procedure. After he is pronounced a Pappataci, food is brought in, and he is tested by Isabella and Lindoro, who pretend to make love while Taddeo reminds Mustafa to ignore them. The lovers prepare to leave as Taddeo suddenly realizes that he too is being tricked and tries to rally Mustafa, who as ordered pays no attention. Mustafa takes Elvira back and everyone sings the praises of the resourceful Italian woman.
