When Police kicks open the doors of the elite underground fight club Knuckledust, they find seven levels of hell, filled with the dead bodies of countless fighters, assassins and goons. Only one man, beaten up to a pulp, is still breathing: Hard Eight. A former marine is trapped in an elite underground fight club. When cops swoop in they discover only one man left alive, him. But all is not as it seems. Is he the sole survivor or a mass murderer?