Batman faces off against Gorilla Grodd in Arkham Asylum while attempting to destroy Grodd's new invention, the Quake Engine. As chaos erupts, the engine activates, causing the entire asylum and Batman to vanish. When Batman reappears, he realizes he's in feudal Japan and is immediately attacked by samurai seeking to kill him. Further investigation leads Batman to discover the Joker is responsible for the death order and is now the dominant warlord ruling over Japan. To return home, Batman must reactivate the Quake Engine found in the remains of the Arkham Castle, but his resources are limited, only armed with his gadget belt. Follow the journey of Ninja Batman as he faces familiar foes in a strange new world while attempting to return to Gotham in one piece.