The Worlds Greatest Heroes (the JLA) and the Original Super-Team (the JSA) have teamed up to save the world again and again in times of crisis. This year the two groups engage in a world-shaking adventure that results in an all-out slugfest so colossal that only a 96-page hardcover can contain the epic that fans have been clamoring for! Villains from the rich histories of both groups hatch an insidious scheme that lays waste the heroes and the world they defend. But of course these are no ordinary heroes... What starts as a friendly get-together between the JLA and JSA degenerates into a destructive melee and from the ashes rises a villainous uber-team made up of select members from each team.