Three clades of expanding and changing humanity are fighting a war in the Fomalhaut system. The Quicks got there first, then the Trues came along and enslaved them and now the Ghosts are here driven by their beliefs to claim the mysterious heart of the worldlet Cthuga. A True librarian in disgrace is despatched to find a missing scion of a powerful family. A Quick bot pilot encounters a mysterious sprite which may be part of a living Mind. A young Child grows up in an old garrison town in Greater Brazil, and because of the nature of the conflict in Fomalhaut, it is crucial that she grows up a certain way.

Big, sharp, clever sci-fi. You have to work at it; there's a lot to process in terms of history, technology, philosophy and sociology. A lot of big concepts and quite a few small ones. It all comes together in the end to a satisfying conclusion.