 A prominent corporation in the series, called PROBE-NEXUS, moves its base of operations to the ruined east side and begins reconstructing the area.The rebuilt area flourishes again as it becomes a wealthy and busy city known as Zone Prime, which serves as the backdrop for many locales in the game.In the underground of Zone Prime, PROBE-NEXUS also sponsors a tournament known as the Fight for Survival, or F.F.S., where fighters are gathered from the city's slums and compete for sport.