I wasn't sure what to rate this - I kept waffling between 2 and 3 stars - but eventually decided to give it the higher rating because I did mostly enjoy the book and I'm generally a big fan of the author. It was truly wonderful to dive back into these characters' lives, and the dialogue was excellent (and I love that David finally got a good metaphor in!). Knighthawk's texting with David was fantastic, and the new city we visited (what was once Atlanta, now a moving city made of salt) was really interesting. 
 The ending, however, was where it all fell flat for me. (view spoiler)[It felt really rushed and I think it left us with more questions than it answered. And honestly, the whole thing with the villain changing his mind after seeing the good of humanity was, at best, eye roll inducing and felt like a big cop out. Everything felt too easy. I also thought the epilogue was unnecessary and actually took away from the book rather than adding to it. (hide spoiler)] 
 Overall an enjoyable, if somewhat disappointing read.