This felt like a satisfying end to the series to me. I found the concepts of the purity war and the experiment cities frustrating, as I couldn’t understand how a future government so advanced could completely overlook the problems and aftermath of gene editing. I was also surprised that Tris was willing to sacrifice her brother so easily, even considering his actions in the previous book. Having said that, I enjoyed how this final book flipped everything we learned in the previous books and I liked how Tris’ death contributed to change in the end. So swings and roundabouts.