Ancillary Justice

Ancillary Justice is a space opera set thousands of years in the future, where the primary galactic power of human-occupied planets is the expansionist Radch empire. The empire uses AIs to control human bodies ("ancillaries") that are used as soldiers, though regular humans are also soldiers. The novel follows Breq, the sole survivor of a starship destroyed by treachery, and the vessel of that ship's artificial consciousness, One Esk Nineteen, as she seeks revenge against the ruler of her civilization. The plot switches between two strands: Breq's "present day" quest for justice for the Justice of Toren's destruction, and flashbacks from 19 years earlier when the Justice of Toren was in orbit around the planet of Shis'urna, which was being formally brought into the Radchaai empire.