Batman encounters a new cat burglar calling herself Catwoman, and around the same time, meets a woman named Selina Kyle (as Bruce Wayne), to whom he is visibly attracted. When Selina runs into trouble with a terrorist group known as The Red Claw, who want the mountain lion sanctuary she was trying to protect, she decides to take matters into her own hands and investigate.

Bitter scientist Victor Fries, as Mr. Freeze, attacks several divisions of GothCorp, each time stealing a piece for a secret weapon he intends to build. Batman investigates the connections, and discovers that the start of Freeze's vendetta against GothCorp was a bitter falling out between Fries and GothCorp's CEO, Ferris Boyle (Mark Hamill), during which Boyle almost killed Fries (mutating him into Freeze) and presumably killed Fries' terminally ill wife, Nora. Batman must find a way to bring Boyle to justice before Freeze carries out his revenge.