They mark humans who have been taken into their society as being in-enze or in the group/family. Donovan is one such human, who is a soldier-in-enze, which means he belongs with a group of other humans and Zhree where he acts mostly as a police force but is called for anything unsettling. Donovan is also Hardened, which means he has been given a exocel (Exo for short) or an upgrade which provides him with armor and defense/weapons that seamlessly integrates with his mind. He is also the son of the Prime Liaison, who theoretically holds the highest position because he interfaces directly with the Zhree (versus the President who only controls humans/has less power).
Donovan doesn't question his life or his role- until one night while on patrol, he and his partner perform a search for sape intel and find more than they bargained for. The Sapience is the human rebellion who wants to expel the Zhree from Earth and rule the planet without them- they are viewed as terrorists and frequently bomb and kill humans in their quest. This is not to mention that they also execute exos at will, because they are seen as being pets of the Zhree and no longer human. On this raid, Donovan and his partner come under fire and Donovan is captured- once they find out who he is, they decide to use him as a bargaining chip rather than kill him outright.
During his capture, Donovan learns that the sides may be more nuanced than he thought and that there are some areas of gray. What is really unique about this book is that there is a lot of gray and both sides are presented in ways that make sense. It really shows a much more three-dimensional struggle around colonization and suppression that you don't often see in YA books. The Zhree aren't necessarily evil and they do treat humans well- but the humans aren't really free. So what do you do?
The questions and thoughts raised by this book are infinitely engaging- as is the fast-paced and adventurous plot. We really get to see both sides presented and dissected by Donovan as he is pulled in both directions. I am really interested to see how this series evolves and whether these big questions are answered or continue to spark a lot of discussion/debate. Overall, I think it was really fantastically done and a truly unique book- you'll definitely want to check this series out if you enjoy YA sci-fi! Please note that I received a copy through a giveaway. All opinions are my own.