Leporello, the vallet of Don Giovanni, is angry at his master for making him wait outside again while he goes off seducing young ladies, but this time, the girl chases him out and demands to know who he is. Her father comes out to defend her honor, gets killed by Giovanni in a duel. Master and servant run away just as Anna brings a crowd and makes her fiance swear to avenge the wrongdoing.
Leporello tries to make his master forsake women, which almost earns him a beating. This is interrupted by the arrival of a mystery lady who's apparently out for revenge on a lover that fled from her. Just as Giovanni tries to seduce her, she turns out to be Elvira, an already-seduced woman who hasn't given up on him. He flees the scene while his servant distracts her, as per orders, and tells her everything about the Don — or, more accurately, about the long list of women he already nailed. Elvira, despairing, vows revenge.
The young peasants Masetto and Zerlina are getting married. Giovanni and Leporello gatecrash it by accident and the Don invites all the peasants to his castle, already eying the bride. His noble status shuts up the grumbling groom and he completely charms the bride... until Elvira bursts in, cursing him and leading Zerlina away. Almost instantly, Anna and Ottavio show up, the former pleading for his help. Giovanni tries to butter up to Anna again once he realizes she doesn't know who her would-be seducer was, but Elvira returns. Giovanni claims she's insane and she rushes away again, though Anna and Ottavio begin to doubt who to trust.
Just as the Don leaves, Anna realizes that it was him who skewered her dad by voice alone. Ottavio asks her to tell him the whole story and she does, in a rather bombastic aria di furia. She then runs off, leaving him to muse on his love for her.
Leporello decides to quit just as the Don happily returns, eager to get him some village girls. Apparently, Elvira returned and attempted to rage, but the servant locked her out in the garden.
Meanwhile, Masetto and Zerlina argue about her supposed infidelity. Just as Zerlina manages to convince her beau of her innocence, they hear Giovanni coming and Masetto becomes paranoid again. After finding Masetto mid-seduction, the Don postpones his conquest of the peasant girl.
Outside, three masked people — Anna, Elvira and Ottavio — have come to gatecrash Giovanni's party. They get invited in just in time to hear Zerlina scream. The Don blames everything on Leporello, but no one believes him and he makes his escape by dumping his servant on them all.
In act two, Leporello is about to quit, but he's silenced by some quick cash. Giovanni proceeds to bully him into the Bed Trick to get Elvira's chambermaid. It works better than expected; Elvira falls for it too, believing Giovanni has returned for her. A Masetto-led mob interrupts the Don's serenade, but he deals with them and even beats up Masetto himself, who gets nursed back to health by Zerlina.
Leporello shakes off Elvira, but runs into everyone else and is about to get killed when Elvira proclaims him to be her husband. When the deception is revealed and Leporello quickly flees, Ottavio vows to bring justice to them all. Elvira rages at the continued betrayal, but realizes that she still loves Giovanni despite everything.
Meanwhile, the Don has wandered into a graveyard where the Commander got buried. Once reunited with Leporello, who fears the statue, he makes his servant ask it to dine with them. Shockingly, it accepts.
Anna asks Ottavio to wait with the marriage when he pressures her. Rather pointless scene, rather spectacular aria.
Giovanni has yet another dinner party only for himself. Elvira turns up, begging him to change his life; he laughs it off. The statue turns up for dinner — that, he doesn't laugh off. When invited to dine with the statue at its home, he accepts, claiming that he isn't afraid of anything. When they shake hands, he feels the grip of iron and coldness near his heart; the Commander claims that this is his final moment and that he must repent. The Don refuses over and over and is, ultimately, dragged down to hell with the statue.
Moments after, the rest of the characters burst in to find a frightened Leporello cowering beneath a table. They realize they had been avenged and a general happy ending is told in the final chorus — the moral of the opera.
After all, questo e fin di chi fa mal — this is the end of one who did evil. "The death of a sinner always reflects their life." So remember, kids, first comes marriage, then comes love!
