The gang czar Mister X terrorizes Gotham City, and decides he wants to work with Catwoman. Batman and Robin are shocked to hear from Commissioner Gordon that Catwoman has been broken out of jail with dynamite. Mister X offers to plan heists and have Catwoman commit them so they can share the loot. Catwoman works with X's henchman Dipper, and they make fun of a wannabe crook named Mousey.

When Catwoman leaves her hideout, she finds Batman and Robin waiting for her. They try to give chase, but she throws a box at them with angry cat inside it. Batman runs towards falling debris, and Catwoman realizes he will be killed. Instead of escaping, she leaps to save Batman's life and gets hit in the head by a brick.

They wake her up in the Batcave, where she feverishly screams about airline rules. It's revealed that Selina Kyle was a stewardess, who fell out of a crashing plane and got amnesia. Kyle is horrified to hear that she's become a criminal in her amnesiac state. Batman asks about her obsession with cats, and she explains that her father used to own a pet store. He taught her all about cats, and she subconsciously remembered that through her amnesia.

Gordon asks Kyle to go undercover and help them take down Mister X. Mousey is brought into the station and hears their scheme, so Gordon has him put in jail. Mousey breaks out with a hidden file, swearing revenge on Catwoman.

Catwoman pulls several heists for Mister X, although crime now disgusts her. This includes distracting a record company with cats while she steals gold-plated records, and opening a bank vault with cats. Batman and Robin fight her on a Giant Cash Register, but this is a ruse so they can fake being captured. Catwoman takes them back to Mister X, who locks them alone with a time bomb. Mister X tells Catwoman he knows about her treachery, and has her dragged off a cliff via tractor. Batman and Robin escape in time to rescue her and punch out Mister X's thugs. It's revealed that Mousey was Mister X all along. He wore a bulky costume to make other crooks respect him.

In the aftermath, Selina Kyle officially retires from her career as Catwoman. However, Batman insists that the police may still need her as an operative -- sooner than she thinks.

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