Joker and Harley Quinn obtain the legendary mask of Loki. Combining his own powers with one of the oldest relics in the world. He starts to become a TV superstar but Batman is nowhere to be found. But Harley Quinn becomes jealous causing her to hire Poison Ivy who angers Joker/Mask that he will set off a bomb that will destroy Gotham City. But the caped crusader has plans of his own.