Earth is in crisis, virtually destroyed by overpopulation, and mankind is teethering on the edge. ISTO - the Interstellar Trade Organization - had demanded man's extinction, for a living planet is more important than any race upon it, and was about to start 'reducing' mankind when Earthgov agreed its demands, to sell 90 per cent of Earth's inhabitants into bondage to alien races. When Margaret is six, she imagines herself as a spy, a healer, a queen, a warrior, even a boy, to amuse herself; when she is nine, and 12, and 20, at crisis points in her life, she feels like parts of her have split off - like the Margaret who decided to follow her lover to Tercis and the Margaret who said no. So now, as well as Margaret, she is Wilvia, learning to be a queen on B'yurngrad, and Ongamar, a spy on Cantardene, and Gretamara, a healer on Chottem, and even Naumi, a boy on Thairy, and she is many other Margarets besides. And all these Margarets hold the key to mankind's survival, if only they can survive and come together again as one Margaret, with all their different powers intact . . .