While battling Gorilla Grodd at Arkham Asylum, Batman is caught in Grodd's Quake Engine time displacement machine and sent to Sengoku period. There, he is chased by samurai working for the Joker (character). During his escape, Batman meets up with Catwoman, who reveals everyone else arrived two years earlier (due to Batman being in the outermost area affected by the Quake Engine). He learns from her that all of Gotham City's top criminals have become feudal lords after deceiving the Sengoku period daimyō, battling each other until only one state remains. In order to stop the villains from changing history, Batman and Catwoman must get to the Quake Engine in Arkham Castle (formerly the asylum). Batman discovers that Alfred Pennyworth is also in the past and has built a Batcave outside Edo.