Towards the end of the twenty-first century 41 Worlds, small satellites with a total population of half a million, orbit the Earth, which has seen many changes, not least of which is a second revolution in America. Marianne O'Hara, a brilliant political sciences student, is from New New York, a hollowed out asteroid and the largest of the Worlds, but is to spend a year on Earth as a postgraduate student. Because the political relationship between the Worlds and Earth is complex and voltatile, Marianne unwittingly finds herself caught up with a group of fanatics determined on a third revolution in America - even if such a revolution could lead to the destruction of the Earth...