Act 1
Ali Baba’s palace
Morgiana and Ali Baba’s other servants admire their master’s riches. They wonder why the customs office has not yet seized his prize barrels of contraband Moka. Ali Baba enters and states that being the richest man in the land brings him more joy than anything. In contrast, Ali Baba’s daughter Delia is heard singing about how love brings greater happiness than wealth. Delia is in love with a man who has no money, and Ali Baba has forbidden her to see him.
Aboul Hassan, the captain of the custom office, arrives and announces that he knows about Ali Baba’s stash of Moka — but he’s willing to overlook it if he can have Delia’s hand in marriage. To Delia’s consternation, Ali Baba agrees to this arrangement.
In private, Delia tells her lover, Nadir, of her father’s promise to Hassan. They vow to love each other eternally despite the situation. Ali Baba enters to find them embracing and banishes Nadir from the city.
A wooded area outside the city
Nadir laments the loss of Delia and wishes for enough money to be worthy of marrying her. He hears men approaching and hides as Orsocane and his forty thieves arrive.They speak the magic words, “Open Sesame,” and a nearby rock rolls away to reveal a cave, within which their plunder is hidden. They seal the cave again and leave. Nadir realizes that he now has access to all the wealth he needs to marry Delia.
Act 2
Ali Baba’s palace
Delia mournfully prepares for her wedding, pining for Nadir. Hassan enters, hoping to woo Delia, who rudely rejects him. Ali Baba chastises her for her attitude.
Once Hassan has left, Nadir enters and once again asks for Delia’s hand in marriage, this time promising Ali Baba all the wealth that he could want. Ali Baba demands that Nadir tell him wherethese riches came from, and Nadir reluctantly tells him, swearing him to secrecy. Ali Baba agrees to let Nadir marry Delia.
As Delia and Nadir begin their wedding festivities, Hassan enters to find that he is no longer engaged to Delia. He threatens to throw Ali Baba in jail and confiscate his Moka. Ali Baba, wanting to save himself and his riches, calls off all wedding plans and pledgesto lock Delia away in another castle.
Act 3
Ali Baba’s palace
Morgiana is alone in the palace now that Delia is en route to her new castle. Suddenly, news arrives that Delia has been kidnapped. Nadir, Morgiana, and Faor leave to chase after the kidnappers.
Inside the thieves’ cave
The thieves talk in their sleep about their dreams of feasts, plunder, and battle. Upon waking, they talk about their plunder the day before — a beautiful woman, who happens to be Delia. Orsocane lewdly harasses her, and she rejects him. The thieves leave for their daily mission.
Ali Baba appears, having used the magic words to enter the cavern. He attempts to steal several things, but he is trapped when he discovers that he has inadvertently destroyed the paper containing the magic words. The thieves return, and Ali Babais discovered. Delia enters and finds the thieves about to kill her father. On discovering who he is, the thieves instead decide that Ali Baba will pay a heavy ransom for his and Delia’s freedom.
Act 4
Ali Baba’s palace
A homecoming banquet is being prepared for the safe return of Ali Baba and Delia. They arrive home with Orsocane in tow, and the remaining thieves hide inside the Moka barrels, waiting for the right moment to plunder the castle.
As Morgiana checks on the Moka for the banquet, she discovers the hidden thieves and alerts Nadir to their presence. They hint at a scheme to make the thieves pay, and Nadir exits.
With the banquet underway, Orsocane forces Ali Baba to sing a drinking song. Suddenly Aboul Hassan and hisofficers arrive to exact revenge on Ali Baba, and they set fire to his Moka barrels. The thieves are smoked out and quickly arrested. As Ali Baba mourns the loss of his Moka, Delia and Nadir embrace him as his daughter and son-in-law.
