1980年代，美苏衝突不慎释放出上万隻潜藏在地球，名为「卓巴」的外星人。不料带有病毒的卓巴引起致命传染病而受到地球军团剷除，卓巴灭绝后，军团随之解散。多年后，昔日军团成员却意外遇刺，疑似尚未被根除的卓巴前来复仇，剩馀的军团成员必须找到彼此，在被卓巴变种人杀死前，找出反击之道。...

For centuries we have dreamt of reaching the centre of the Earth. Now scientists are uncovering a bizarre and alien world that lies 4,000 miles beneath our feet, unlike anything we know on the surface...