I though that this book was a little darker than the other ones she'd written. I mean I still loved it for sure and am super stoked for the last one--as well as sad--, but it was a little dark. I found myself growing increasingly frustrated with Zach and Cammie's relationship. I was like "Be a couple already will you, and save the suspense!" It was a great addition and answered a lot of questions. It made the series a teensy but dragged out because there wasn't that immediate sense of emergency, though there was once. The way she forgot her memory and new creepy stuff, like how to kill, receives huge points because of the fear and realism that Cammie might be dangerous. Over all I really liked it, but like I said, Dark.