First off, this book had me reading well into the night. It was very good. The point of view flips back and forth from Tris to Tobias with each chapter which actually worked really well. I liked seeing his side of the story and the events still flowed smoothly. It's funny because it seems to me like these two characters have almost switched personalities since the first book. Tris now being the true risk taker and Tobias being more fearful and unsure of everything. Their relationship however, grew and endured through the multiple problems/tragedies within the story and I was happy that they didn't give up on one another.
I thought this book was the darkest of the three. The plot begins where Insurgent left off and Tris is freed from prison by overcoming the truth serum and convincing Evelyn she is not a traitor. Things in the city have not changed for the good. There may not be factions any longer, but the factionless are in chaos and still unable to make their own decisions about how to live. A group including Tris and Tobias decide to leave the city to see what it is like on the other side of the fence, hoping for something better, but what they find doesn't end up being much better than what they left behind. In this story, many characters risked everything for what they believed was right. Some were separated from their loved ones, and there were quite a few deaths, both good people and bad.
That brings me to the end. I don't believe in spoilers so I will not say anything about what happened except to say that I both loved and hated the ending at the same time. I liked what the author did because I felt that one of the characters got the wish they have been dreaming of and it was fitting. However, I hated the fact that I didn't get what I wanted as a reader. That's all I will say for now... bring on the comments because I have a lot more to say but I don't want to put it here because it will ruin the story for those who haven't had the privilege of reading it yet... and it was a privilege. I am sad that the story is over.