From the back cover:
Superman and Green Lantern are Missing
Nuclear Missiles Have been Stolen and a Mysterious Virus is Driving Europeans Insane
Someone very powerful is seeking to expand their dominion, and Justice League America and Justice League Europe must work together to find out who is behind this massive plot to hold the world hostage!
World in the Balance is a first in the DC HEROES Role-Playing Game line. In this "double adventure", 5 to 7 players alternate between two separate characters, one from each branch of the new post-Breakdowns Justice League. Or is 10-12 DC HEROES players are gathered, half play characters from Justice League America and half play characters from Justice League Europe, with both groups uniting at the end to rescue the Man of Steel and Hal Jordan and save Earth from imminent domination.
World in the Balance features: Detailed maps of the Ferris Aircraft and Aeronautics Proving Ground -- the Mojave Desert and -- S.T.A.R. Labs, as well as NEW statistics for -- The Flash III -- Libra II -- Blackrock -- Brain Storm -- Nightfall, and -- Shatterfist.