A year has passed since Bill and Lance's confrontation with the Red Falcon Organization, but peace proves short-lived. The commando duo receives orders to retake a strategic military base that has fallen under alien control, with most of the stationed troops now serving as possessed pawns. The soldiers must navigate the moral weight of battling their own corrupted comrades while facing an evolved strain of the extraterrestrial threat they thought they had already defeated, forcing them to confront both familiar and grotesquely transformed enemies.