The Principle of Simultaneity is a scientific breakthrough which will revolutionize interstellar civilization by making possible instantaneous communication. It is the life work of Shevek a brilliant physicist from the arid anarchist world of Anarres. But Sheveks work is being stifled by jealous colleagues so he travels to Anarress sister-planet Urras hoping to find more liberty & tolerance there. But he soon finds himself being used as a pawn in a deadly political game.