This is a brilliant book of far future military space opera with a twist. The key advanced science that is active in the worldbuilding and the plot is mathematics rather than physics, which gives a very distinctive speculative feel to the world built around the plot, and may lead confusingly to some readers being convinced that the book is “hard” sf, and others equally convinced that it is fantasy in sf disguise.
Mathematics is central and its application by means of “consensus mechanics” allows the override of classical physical law by “exotic” effects (including faster than light travel). To maintain these exotic effects the whole social order must be organised around a particular “calendar” that is a multi-level synchronic order: all at once axiom-system, creed, political order, and psycho-physical discipline. “Doctrine” is all-important, and the worst crime is “heresy”: not just dissidence but also the use of deviant technologies that rely on unorthodox axiom systems.
Another central intellectual discipline is philosophy, important for its absence and also for a heretical (i.e. doctrinal, technological, and political) attempt to re-introduce it into the current ruling order, a hexarchate based on six factions (a warrior caste – the Kel, a spy/assassin caste – the Shuos, a programming/inquisitorial caste – the Rahal, a disciplinary/brainwashing cast – the Vidona, a wealthy/cultured class – the Andan, and a mathematical/technical caste – the Nirai).
Previously the Liozh, the philosopher/ethicist caste, formed the seventh faction in a “heptarchate” but the whole faction was eliminated for heresy, something to do with trying to introduce democracy and to free people from compulsory ritual observance of the “remembrances”.
These underpinnings only emerge slowly. From the beginning we are plunged into the action of the novel, a strange battle with “heretics” making use of weird technologies, and a dazzling vocabulary to describe it. The opening pages, narrating the first battle sequence, underline the theme of the absolute obedience required by an authoritarian and unreliable high command willing to sacrifice its soldiers and its stated objectives for inscrutable reasons.
Our protagonist, heroine and viewpoint character is Captain Kel Charis, courageous, loyal, a mathematical genius, and yet full of empathy. We see this alien world through her eyes and she gives sense and value to it all, even as that sense evolves during her new mission, which leads her to discover much that she was unaware of concerning the secret history and underside of the world she knows.
The ultimate stakes are the continued existence of the hexarchate itself, which she has been conditioned to serve blindly and unquestioningly. Can she avoid the omnipresent danger of “calendrical rot”? This is the ultimate menace as our very actions taken to save the calendrical order and strengthen it may change our assumptions and lead us to deviate from the Calendar and so to weaken it. Or perhaps it is desirable.
Where oppression is synchronic (stasis) resistance is diachronic (rot).