Synopsis: Ian Douglas of 1980, discoverer of the knot in Time, became Captain Gart of 2170 by accident. Once in that role, he dared not change, for the world was fighting a desperate battle for survival. The shattered remnants of the American East were hanging on grimly in the face of maniacal attacks of bestial men. Across the seas a matriarchal order had grasped the fallen reins of science and provided the last hope for a civilized future. Gart/Douglas, with his forgotten skills, could be their best tool. But as a tool he held martial capabilities and scientific abilities they could not suspect. (from the back cover of the first edition)