I didn't enjoy this as much as I was hoping to. The action goes right up and then just slows right down then speeds up again. I swear, I felt seasick when I'd finished. The action was good in places but the situations that Four/John gets himself into feel silly and not very believable. Indeed, it felt as if the Authors had just picked a situation out of a hat.
Characters wise, quite stereotypical. Sarah, the love interest, just wasn't for me. I'd prefer a girl that knows how to fight or at least is willing to learn. Unfortunately Sarah screams at everything, a typical girl-next-door character. She claims to hate Mark. her ex, who relentless picks on John from the first day but if she does then why does she follow him around everywhere and sits next to him in class? That makes no sense.
All in all, a good read if you've got nothing better to do and want to say 'I read this!'