It's a few thousand years from now, a time of widened horizons but all too familiar contours. The nine known worlds have joined in a sort of interstellar U.N.; the government of Urras has peacefully diverted its anarchists to a world of their own, Anarres, the moon; and now an Annaresti physicist named Shevek (cast in the mold of the ancient Terran Ainsetein) has formulated a theory that will dissolve the barrier of time, only to confront the confounding limitations of humanoid politics. This could so easily have been so bad -- the Cold War opposition of Anarres and Urras, grimly heroic collectivity versus brilliant, corrupt high civilization, and these as seen by a character of such unmitigated nobility, who would be disruptive in any society in any case -- it is amazing how Le Guin has lightened it up, made it all plausible, and not only that, restored the impact of her point, which is made late and glancingly. The novel flashes back and forth, before and after Shevek's historic trip to Urras, which ends centuries of segregation, and delicately develops both the strengths and weaknesses of the two social systems, the contrasting textures of two kinds of social experience. On Anarres Shevek was a frustrated "egoist"; on Urras he is an exploitable novelty. But in both worlds, there are relationships, and things done in certain ways, and objects firmly there to be seen; and Shevek, in the usual slot of naive-genius plot convenience and destined Charlton Heston vehicle, is a complete, fully active mentality. All through, this impresses with small but incalculably right choices which add up solidly and confirm Mrs. Le Guin as one of our finest projectionists of brave old and other worlds.