The Joker attacks Gotham City's Mayor's office, but is foiled by Batman, who escorts him for incarceration at Arkham Asylum. The same night, a mysterious fire at Gotham City's Blackgate Prison has caused several hundred prisoners to be temporarily relocated to Arkham, many of whom were among the Joker's most recent crew. As Batman escorts the guards taking the Joker inside, the asylum's security is overridden by Harley Quinn and the Joker is able to escape and take control of the facility, enlisting the Blackgate prisoners in addition to other rogue characters imprisoned at the asylum. Batman quickly realizes that this has been part of Joker's plan including the Blackgate fire, having double-crossed a security guard to help him escape. The Joker threatens to blow up bombs scattered around Gotham City should anyone attempt to enter Arkham, forcing Batman to work alone; however, Batman is able to rely on Commissioner Gordon and other loyal guards, after Batman is able to free them, to help secure prisoners he has defeated, and Oracle is able to guide him through the Asylum over the radio. Now, it is up to Batman to stop Joker's plan before Gotham turns into a second home for the criminally insane. BONUS for PS3: players who buy the game for the PS3 will get to play as the Joker.