This book was not perfect. Let's get that out of the way first. There are some issues with Weeks' storytelling techniques. That said, this book was stronger than the previous two in the series. The story takes several unforeseen turns in this book and the scope broadens considerably.Let's get the bad stuff out of the way first. This author continues to rely far too heavily on Deus Ex Machina. Too many plot points are generated by random coincidence, impossibly bad luck or timing and just generally unlikely occurrences. It has reached the point where it is a bit off-putting. The amount of times that an incredibly unlucky series of events creates drama or tension in this book is excessive. There also seems to be frequent artificial compression of time. All of a sudden, several important things will happen all at once and there is often no logical reason why that would be the case. These are things that you can get away with in a good story but not if you do it too frequently.There is also the issue of the continued struggle for the main characters to safely store important items or information. For some reason, in a world in which there are giant rotating islands, there doesn't seem to be a reliable way to put something important in a safe place. There are no safes or lock boxes apparently. The bane of the main characters' existence is someone simply entering their room while they are not at home. Again, this could have been used once or twice in the series to good effect but it's just excessive that there seems to be no solution to this problem no matter how long they live at the Chromeria.Complaints out of the way, let's get to the good stuff. This book really delves deeper into the history of the world that the story takes place in. You learn a lot about the larger context and it serves to greatly enrich the overall narrative. The evolution of many of the characters is really impressive and the author clearly has solid insight into human psychology and emotional development. Gavin, in particular, is made to examine his own beliefs and perceptions. He goes through hell and we actually begin to see the corner he has painted himself into.As for Kip; he has become a very interesting character. While some of his changes seem to come on a bit too quickly, he clearly evolves both intellectually and emotionally in this book and has become a much more interesting protagonist. He also evolves physically, although perhaps the author has a bit to learn about physical fitness. A teenager who spends an entire year training with an elite military unit rigorously (and goes through a period of extended starvation) would not still be fat.Other characters like Teia and Andross are also really well written in this book but the plot is the star of the show. It's genuinely unpredictable and the author never falls back on black and white, good versus evil tropes. I'm excited to continue reading.