"Mankind hid beneath the ashes of the nuclear fire, driven to the brink by the relentless war machines of their enemy's crusade to exterminate humanity. Its earliest attempts were sheathed in rubber skin. But the newest version...is superior, stronger, deadlier..." -- In the wake of post-apocalyptic war, the human resistance soldiers learn the hard way that their adversaries have upgraded their arsenal with an INFILTRATOR unit, designed to destroy them from the inside.