Target Audience: Teens/Young Adults/Adults
The characters are varied and are related to in such a way you can't help but feel for them, even the ones that you really think you should hate (you'll understand what i mean when you read it). Unlike a lot of writers, Higson is not afraid to lose any of his characters and this makes the story all that more realistic and emotional. At some points i found myself so attached to some of them that when they died i found myself feeling quite upset. Despite the fighting and the violence, the more difficult issues are handled sensitively and with humanity and a way that really makes you care.
With regards to the title of the book, during the few chapters the obvious 'enemy' are the grown-ups, but the lines become blurred as the children quickly realise that enemies come in different shapes and sizes and it becomes clear that the 'enemy of your enemy' is not always your friend.
I can't say anymore without spoiling it, but this is one of the most revealing, emotional and action-packed books i've ever read. I can't wait until the next in the series.