Keeper of the Lost Cities

I would give this a 4-4.5. I came into this book knowing that it was a middle grade, and didn't expect what I got.
At first everything was moving extremely fast, but not in a natural sort of way and because of that I thought I wasn't going to enjoy the rest of it. About a third the way through though things began to slow down and there were a ton of layers to the story. I blasted through it after that and really enjoyed it.