经历过外星人大举入侵地球后,人类知道,这些入侵者有一天一定会再回来。人类运用先前外星人所遗留下来的科技文明,发展出一套强大的地球防御系统以抵御外星人的再度入侵。然而,20年后,这些外星人却带着人类前所未见、更先进强大的武力再次入侵地球,带来更大的全球灾难,几位勇敢的年轻人,他们挺身而出,将再一次为人类生存而战斗……Two decades after the freak alien invasion that nearly destroyed mankind a new threat emerges. This Alien mothership is more than twice the size as the last one and once again, the world's armies must band together to save the world. Do they have enough firepower or will this battle change and will aliens take over?