It's Halloween in Gotham. To celebrate, the city's spookiest villains -- Scarecrow, Clayface, Solomon Grundy and Silver Banshee -- have joined forces and gone on a crime spree. With Green Arrow, Cyborg, Nightwing and Red Robin, Batman swings into action to stop them. But it seems the fiends are working for the clown prince of crime himself, The Joker, who has a surprise of his own: a computer virus that makes all technology laugh and obey his every command! Can the heroes stop the virus before it turns all of Gotham into Jokertown? Will Batman find a way to beat the Joker now that his trusty gadgets and vehicles have succumbed to "digital laughter"?