Caine Riordan and his self-styled "Crewe" have survived their first months on the planet they call Bactradgaria. They've overcome floods, dust storms, tornadoes, searing heat, bitter cold, desperate battles, and attacks by various strange species. However, their most desperate struggles have been against the wildly ferocious x'qao, for whom the pursuit and genocide of other beings is as much a sport as it is a strategy.

Accordingly, Caine and his friends realize that if they are to endure, they must not merely survive but thrive. So far, they've done just that and made friends along the way. But a few scattered tribes and towns can't defeat the x'qao and their vassals. To do that, humans must claw higher up the food chain . . . before they tumble off into extinction.