"The spookiest villains in the city are going on a crime spree. Batman has no idea that Scarecrow, Clayface, Solomon Grundy, and Silver Banshee are secretly working for the most monstrous man of all, the Joker. The Joker is about to release a computer virus that will give hi, control of all technology. He thinks he's in for a Halloween treat, but Batman has a trick up his sleeve: His pals Green Arrow, Cyborg, Nightwing, and Red Robin are joining him to fight back!--Jacket flap.