The human colony world of Paradise is a frigid mockery of habitable, inhabited mainly by the nightmarish, night-loving, Shearers. Commander Carter Jensen's mission to escort a wayward professor back to Eden Base to face justice has taken too long, and night is about to fall. The alien shipwreck is their only chance of escaping the Shearers and surviving the night. But the alien ship haunts Jensen's mind, constantly whispering to him. Are the voices real, or are they just in his mind?