军方发现一个奇异的蛋形物,在研究它的过程中发生了许多难以理解的神秘事件。另一方面,警方接到许多神秘失踪案件,失踪者都是女性。最终人们才把这两件事关联起来,原来是木卫三的外星人因为人口危机而到地球来绑架地球女人去帮他们繁殖。The inhabitants of Ganymede need to find mates from another world or they will become extinct. They soon discover a suitable breeding stock amongst the females of planet Earth.