This is a very different book from Divergent. In a way, it almost makes Divergent feel like a prequel, a book to set up the worldbuilding and characters before the real story could begin. It's full of tense moments, daring escapes and rescues, and a lot of hard choices. There are also a lot of emotional highs and lows: Tris experiences the extremes of grief, guilt, rage, despair and love. I had some issues with keeping some of the minor characters names straight, and some of the internal logic, but when all is said and done, I really enjoyed it.