At the dawn of the 23rd millennium, the world is a husk of its former self. Once, a united world stood on the doorstep of the stars, but now empty skyscrapers serve as nothing more than reminders of past glory. Humanity survives in crowded, underground bunkers, hidden from the new dominant species in the world, the mutants born from the scream that pierced the world.

A decade after the Scream, humanity crowds together in underground arcologies, Holdfasts, networked together through a world-wide system of tunnels. Armed with an array of advanced technologies, and their primary weapon, the Mechanized Humanoid Vehicle, humanity fights on into an uncertain future.