This book really lived up to the hype for me.
It played with my head on many levels. The plural POV's from the same protagonist, the lack of identified gender roles, and the unreliable emotional interpretations of the AI heroine Brecq make for a dizzying, ultimately liberating reading experience.
The story is told in alternating time periods. In the first we meet One Esk, one of thousands of 'ancillaries' (corpse soldiers controlled by AI) of the sentient spaceship, the Justice of Toren. Through her eye(s) we see a story unfolding on the conquered planet of Ors. A new and inexperienced governor, Lieutenant Awn, from the conquering Radch race, is torn by her loyalty to the teachings of the Radch and her growing respect for her 'subjects'. Outside events seem to be conspiring to threaten her position. The narrator, One Esk, is Awn's assistant. She is controlled by her programming but she has always been different. A massacre in which she (as the ship and other ancillary bodies) took part years earlier has changed her more than anyone realises. A terrible tragedy rips everything apart and the second timeline is what happens 19 years later when Brecq, the only remaining appendage of the Justice of Toren and all her ancillaries, plans a terrible vengeance on the lord of the Radch, the omnipotent Anaander Mianaai.
This is space opera at its best. It is intensely personal and galaxy-spanning at the same time. The events on Ors really cement Brecq as a tragic and heroic figure. Her quest across many years and planets, the insertion of the mysterious Seivarden as her companion, and the confrontation with Anaander kept me interested the whole way. The only problem I had was with the ending which was annoyingly abstract in terms of the villain's role and motivations. I found the process of creating the 'ancillaries' to be enjoyably hideous. I would have liked to see more of the changes that happened to stop that practice by the Radch. But this occurs in the time between the two POV's.
This whole book was a series of 'Ah-ha' moments as I caught on to what was happening and new possibilities and interpretations of events opened up. It's the most fun I've had reading for a long time and I can't stop thinking about it.