In a futuristic society, an old man tells the legend of a strange medal to two children. In flashback, we learn that after a nuclear catastrophe, two teenagers were living in an artificial paradise, maintained by electronic means, and once decide to leave that shelter and escape using that same medal - a mini video-disc - in search of outer-space freedom.
Wounded Civil War soldier John Dunbar tries to commit suicide -- and becomes a hero instead. As a reward, he's assigned to his dream post, a remote junction on the Western frontier, and soon makes unlikely friends with the local Sioux tribe.
Ten years after a band of mercenaries first battled a vicious alien, the invisible creature from another world has returned to Earth -- and this time, it's drawn to the gang-ruled and ravaged city of Los Angeles.