With the help of a nefarious billionaire, the Joker and Harley Quinn hatch a plan to lock up the Justice League for good. First they'll kidnap The Flash and Huntress. Then they'll lure the Justice League's most powerful members - including Batman, Superman, and Wonder Woman - into a trap beneath Arkham Asylum. Can the world's greatest team of super heroes thwart the Joker and Harley before it's too late? Or will this perilous pair doom them forever in a Justice League jailhouse?