I was pretty intrigued with the storyline for this. I actually enjoyed about the first half or so of the book, getting to learn the new world and a different kind of paranormal young adult novel. But, unfortunately, that feeling didn't last through the book.
About halfway I really struggled to keep reading. It felt too much tell and not enough show. The first half, to a point, felt good. When Cassie started her trek across the arctic is where I felt the story change to where I didn't like it so much anymore. It's almost as if the story hit a brick wall and continued the story crippled.
The ending seemed abrupt. If it had played out a bit more, if we got to see the resolve of the book, I think I could have rated it another star. There were a few questions I had at the end that I didn't get answers for.
Overall, it's not a terrible book, but I think it could have been so much more.