After breaking Harley Quinn out of Belle Reve, her and her close friend, Poison Ivy, head back to Gotham City. Now that Harley's free, all she wants now is revenge on the Joker for abandoning her, even if it means betraying her friend who keeps telling her to move on. In the streets, the duo encounters a few new faces, one of them is Holly Robinson, adopted by Catwoman, who mysteriously disappeared, and wants answers.
