By the mid-21st century, space has been colonized, and the moon is like the frontier territory of the Wild West. Prospectors, drillers, and a crooked land baron--the exploiters and the exploited--all struggle to survive in this alien environment. A space salvage expert and his partner become involved with a group of criminals intent on hijacking a small asteroid made of sapphire and crashing it into the moon for later recovery. The only place that they can bring the asteroid down without drawing attention to themselves is a mining claim on the far side--but first they must dispose of the miner.