Iain M Banks's latest venture into widescreen, baroque science fiction takes the reader into a war-torn feudal society. Soon the king is murdered by his oldest friend and advisor, the deed witnessed by the presumed-dead prince Ferbin. The prince's younger brother, Oramen, is both too young to assume the throne and unlikely to survive long enough to do so if the murderous regent has anything to do with it. This bog-standard-sounding courtly intrigue is transformed by Banks. The disputed kingdom is located on a vast structure something like a planetary Russian doll, preserved and, to an extent, policed by enigmatic aliens with agendas and battles of their own. Ferbin eventually sets out across the galaxy in search of his estranged sister Djan, who in the years since leaving home has been transformed into a Special Circumstances agent whose job it is to interfere in the affairs of alien races. Despite the author's tendency to spend too long on travelogue and exposition early on, this is another fine addition to Banks's Culture series.