 The Joker is making trouble in Gotham City. First, Joker manages to sneak into the notorious Arkham Asylum. Then, the super-villain releases all the patients from one wing of the facility. When Batman arrives on the scene, patients are wandering the streets of Gotham in a daze, and the bridge to the facility has been destroyed. Joker and Batman battle, but the villain escapes. Later, Joker flies a balloon full of poisonous gas over Gotham. Joker threatens to pop the balloon over the city, and Batman tries to stop him.