Breaking into the asylum, Batman confronted Joker in his cell and used the device on the Clown Prince of Crime. After being subtly suggested to imprison him in the Phantom Zone, the Dark Knight, with the assistance of his ward Dick Grayson, stole a projector from Superman's Fortress of Solitude. To many peoples' surprise, including the villains, Joker surrendered to Gordon and helped capture his allies, sparking suspicion in Batman.Ĭommitted to Arkham Asylum, Joker appeared to stay put and not attempt a breakout, putting Batman in a deep depression. Joker lead the villains, with the exception of Harley Quinn, to attack Commissioner Gordon's retirement party. Watching a report about Superman's banishment of General Zod to the Phantom Zone, Joker was inspired by the number of villains housed there and made plans to break them out. Retreating to his lair, a frustrated Joker lamented about how Batman wouldn't respect him as a villain and how incompetent his allies were. As he gloated about being Batman's "Greatest Enemy", Batman rejected the claims and let him escape to disable the bomb.
As Joker attempted to escape, Batman used grappling hooks to keep him captured.
Unbeknownst to him, the Mayor was actually Batman, who defeated many of his allies easily. As his allies took over the Gotham Nuclear Plant, he released a threat to destroy the city, demanding Mayor McCaskill as a hostage.
Assembling many of Gotham's supervillains and criminals, the Joker lead an attack on a plane transporting explosives.