This is a fantastic, page-turner of a book. The world building is superb and the characters are rich and believable.

But like all great science fiction there is much more to Ancillary Justice than just plot, world and character. Leckie tackles uses the book to ask some genuinely interesting questions about society, language, religion and gender. And beneath all of this is that fundamental question of all science fiction (or at least the sci-fi that I love): what does it mean to be human?

Ancillary Justice tells the story of a large ship Justice of Toren) or rather the ship’s AI. But this is not AI as we currently know it. Much of the book concerns itself with the relationship between reason and emotion. In order to be able to make decisions without looping through millions of possibilities ships have feelings. Importantly ships get attached to certain people just as humans do. Justice of Toren has control of a number of human bodies. She is eventually destroyed and only one body survives. The rest of the story is her quest for revenge.

Interestingly, the Radch (the society which made Justice of Toren) does not recognize gender markers. Throughout the book (narrated by Justice of Toren) almost everyone is referred to with feminine nouns, unless gender needs to be acknowledged in the language being spoken. While this would seem to be progressive, the Radch is a surveillance-based empire that fuels it expansion with a truly disturbing type of slavery.

This is typical of the book. Leckie is asking difficult questions and does not offer any easy answers. Rich though her characters are, their motivations are often obscure. While I initially saw this as a flaw, I now see that this as a key feature of Leckie’s art. While she does use the daily typical “what happens next” hooks to keep the reader engaged, far more compelling is “why did she do that?”

At the end of the book, there is still much that is unclear. Many of the characters are still a mystery, as is the fate of Radch society as a whole. I’m very much looking forward to reading the next book in this series.