The Clown Prince of Crime and the Dark Knight Detective go head-to-head for the last time. The Joker has never wanted to win before, he's never wanted his battle with Batman to end, but now his motivation has shifted. As The Joker's plan to assemble an army materializes, the only person who can save Batman from the brink of true madness is Harley Quinn. And while all this is happening, the villains of Gotham City are waiting out the carnage Joker has unleashed-and Catwoman assembles an army of her own!