Within Arkham Asylum, Batman confronts Gorilla Grodd while attempting to dismantle Grodd's latest device: the Quake Engine. Amid the ensuing turmoil, the engine powers up, and the entire facility instantly dissolves into nothingness—Batman disappears with it. When the commotion clears, Batman stands on an unfamiliar roadway. He quickly realizes he has left Gotham City and now occupies Feudal Japan! His astonishment vanishes as samurai rush toward him, intent on killing him. Subsequent inquiries reveal that the commander behind the death warrant is none other than his arch‑enemy, the Joker. After meeting Catwoman, he learns that inmates from the asylum had been transported there two years prior—each controlling a region of Japan, with Joker reigning supreme. To return to his home city, Batman must reactivate the Quake Engine located in the ruins of the asylum, now called Arkham Castle. Yet a problem arises: beyond his utility belt, all of the gear he once relied upon has disappeared. Ninja Batman shadows the Dark Knight as he navigates this alien terrain, confronting familiar adversaries in a quest to return safely to Gotham. Despite the obstacles, Batman's resolve remains unshaken as he plans his next move to retrieve the engine. He must also outwit the Joker's minions who guard the engine"s core and safety.
