To quote an earlier comment of mine

> Ann Leckie's Ancillary Justice series.

> Culture, gender identity, hive mind, all rolled up into one extremely dense universe with a rich history told through warfare and cutting remarks, humanising potentially inhuman central characters with a vague number of limbs.

> It takes ten pages to get used to the dense yet clipped writing style, but once it clicks, you cannot put the book(s) down: the plot moves forward at breakneck speed.