Batman struggles with Gorilla Grodd in Arkham Asylum, attempting to destroy Grodd's newest creation, the Quake Engine. In the middle of the turmoil, the engine fires up, and the entire institution evaporates into thin air, taking Batman with it. After the dust settles, Batman finds himself in the middle of an unknown road. He quickly learns he is no longer in Gotham City, but in Feudal Japan! The awe fades soon as samurai descend on him, aiming to kill him. Later in the inquiry, Batman discovers that the person responsible for the murder order is none other than his archnemesis, the Joker. Following a confrontation with Catwoman, he discovers that the institution's criminals transported there two years prior, each reigning over a sector of the facility.