I loved coming back to this world and seeing it instead from the perspective of someone who has a very different place in it.  Johnson's ability to take those two perspectives and make both Cara and Scales seem like they have perfectly self-evident worldviews is fascinating, especially as they come into conflict.
This book was messy and heart-achy and lovely in complicated ways and comes the closest to actually answering the question of "how do you make the bad world better"? "How do you fight systemic, ongoing injustice?"
And what I appreciate most about the answer is that the book is willing to wince, but never to flinch.