After the American Army shot down a UFO in 1947, generations of elite commandos were secretly trained to deal with the aliens' feared return. However, the extra-terrestrials never came back and the elite force was disbanded. Sixty-six years after the Roswell crash, the aliens are invading Earth and only the over-the-hill retired commandos can stop them.。兰兰和冬冬是一对姐弟,她们在上海康健幼儿园,父母在北京工作。一天,幼儿园老师告诉兰兰和冬冬她们的妈妈要接他们回去,姐弟俩十分高兴,但由于妈妈工作忙,幼儿园只得请铁路代为运送,铁路局安排郑大光来照顾他们。。