In the distant future, humans find their Earth in a desperate situation. The collapse of nations, fueled by greed, has forced them to expand to other planets. Humans settle across the solar system, almost as the pioneers did, long, long ago. Ushered by this new frontier of sorts and by the free spirit of the day, a new generation of people, lawless bounty hunters, living life on the edge, Cowboys, come into being. The setting in a gritty, less-than-ideal future where lawlessness runs amok. Among this chaos, there is a hapless group of bounty hunters, Spike Spiegel, Jet Black, Faye Valentine and Edward Wong Hau Pepelu Tivrusky IV (Ed). A series of biological attacks brings on a record 300 million woolong reward for the capture of the currently unidentified culprit. The group is all too anxious to pursue the case, but what is strictly business quickly turns to something far more deep and sinister, laying the fate of the world in the group's hands.