Somewhere between 2-3 stars.
Just gonna spoiler up so I don't have to worry about writing anything I shouldn't.
The book starts by announcing that there are lots of questions to be answered, some nice words about logic and then we're off. Sad to say, there's not a lot of logic in the answers we are given. It's too bad because I thought this story, in the first two books, was really compelling. I was hoping for something more along the lines of the Maze Runner. The potential was there, but instead of real answers we got a lot of 'twists' thrown in but they contained more plot holes than plot hole filling.
The world here is based on the government basically wiping people's memory time after time and trying to eliminate 'bad' genes in favor of the genetically pure, or 'divergent.' They set up these isolated cities that know nothing of the outside world, that there even is an outside world, and leave them to reproduce generation after generation. They are offered no guidance or assistance, they are told nothing of their situation, just left to make babies the ever-watchful government hopes are genetically pure. We are told about the government, yet we see nothing of it except this one Bureau of Genetic Welfare. They control everything, it seems, without interference from the rest of this government. I'm not sure who is more naive, the citizens of the experimental cities or the Bureau itself. The way they let our Chicago escapees wander and basically do whatever they want, well, it makes no sense.
The story of Tris' mother is pretty much unbelievable. I don't even want to think about it. It's a hazy story that holds not much substance at all.
Four. Oh Four. What the hell happened to you. It's like he completely broke down into nothing but self-doubt and self-pity. I found it a bit hard to believe his break down. It's not like he had much of a family to hold on to before, he didn't really think he fit in with the Dauntless, yet now he's completely adrift with no thoughts on how to get himself together. He was pretty pathetic during most of this book.
I like Tris. She seemed to be the only character that had any growth whatsoever despite their completely confusing surroundings. The revelations they were receiving once outside the fence were horrible and didn't offer much in the way of hope, but she seemed the be the only character capable to trying to read those around her realistically.
The points of view flipping back and forth between Tris and Four were interesting at the start of the book but their POVs ended up basically blending into one and the same, at times I had to flip back to make sure of who's POV I was reading. I hate that. I really hate that.
The ending of the books is what slants my rating into 3 territory instead of 2. This world that Veronica Roth has created is very interesting, and it would truly suck to live in, so the ending didn't disappoint me. There really weren't any options for a hopeful or happy ending. It sucks what happened to Tris, it sucks that Caleb is still a pansy ass coward. I'm glad Four didn't successfully pursue his plan, even though it would have fit what his character had become. In the end I was just left a bit listless. The characters still with us don't have much hope for anything better in life, seems they are still controlled by this pretty lame government unsure on what the hell they are doing, and are, well, they are just there.
I don't really see how this could have ended any differently, it's not a happy story for sure. But there just wasn't enough real meat to chew on to make this feel successful.