Aliens have come to earth and are decimating it's inhabitants. They are doing this in different waves and each wave comes with a new form of destruction. Cassie has survived all the four waves so far and is now trying to survive in a world which is losing its humanity. But what does it mean to be human in a world without humanity?
This is a matter Cassie regularly wonders about. I think the book perfectly and very realistically shows what it would be like to survive in a post-apocalyptic world. Yancey did this very well, the book has all the desperation and fear but also the hope (or lack of it) you would imagine to emerge as the world ends.
Usually I don't like books about aliens. Their stories are often hard to imagine or just unrealistic. That's also why I was hesitant about reading this book, but I'm so glad I did. It didn't feel like an alien book at all; and it isn't really. It's more about the survival aspect of the story and how to find something to die for when you have nothing to live for.
There was only one aspect of the book that I didn't like and that was the romance. I just didn't really feel the connection between the protagonist and the love interest and it felt a little weird. I think the story would have been stronger without it. Cassie is such a strong character and somehow I think she even could have been stronger without the love interest. But that's really just a minor flaw, since the love story takes a backseat to all the action.
In short, the book is action-packed, fast paced and has an incredible story. It is totally amazing and will pull you in from the first page.