The Earth colony of Landin has been stranded on Werel for ten years—and ten of Werel's years are over 600 terrestrial years. The lonely and dwindling human settlement is beginning to feel the strain. Every winter—a season that lasts for 15 years—the Earthmen have neighbors: the humanoid hilfs, a nomadic people who only settle down for the cruel cold spell.

The hilfs fear the Earthmen, whom they think of as witches and call the farborns. But hilfs and farborns have common enemies: the hordes of ravaging barbarians called gaals and eerie preying snow ghouls. Will they join forces or be annihilated?