I read one review that said they didn't like the book because they couldn't identify with the characters. They didn't care about them, or learn enough about their backstory. To that, I have to ask, has this person never been in a relationship going south? Hasn't everyone? Sarah and David don't need backstory. This isn't that kind of book. We know what we need to know about them. The rest is zombies. The chapter intros made me laugh every time. I already ordered the next book. Great stuff.