The gang is pulled out of retirement to investigate a mystery on a familiar zombie-infested island.

After freeing helpers in Arkham, Freeze and Penguin freeze down Gotham City and attack with huge monsters. Batman responds, helped by other heroes.

The Joker is aided in his Halloween quest to render modern technology useless and take over Gotham City by Solomon Grundy, Silver Banshee, Clayface and Scarecrow.