This fantasy story shadows Fever Crumb, a girl of 14, who was found as a small baby in a cardboard box and was brought up by an engineer. Fever basically missed out on a childhood as the way of the engineer was to suppress all emotions and feelings as they were seen to be irrational and not needed. This is all she has ever known and has no knowledge of her birth parents or ancestry.

The story takes Fever out into the city of London; Phillip Reeve expresses her fear and excitement at discovering a whole new world very well. It shows her internal dilemma, having to choose between this new 'her' and the rational self she has grown up with. This makes her an intriguing character, as you can’t predict how she will cope with the decisions of her new life.

This book is set in the future, but with a huge relapse in technology and general scientific knowledge compared to now, so in some ways it's rather as if it's set in the past. I like the way the author has played with this idea of the future: it’s not like other futuristic novels.

Throughout the story Fever goes through an immense journey of discovery: she matures and finds that not everything can actually be explained with science. I liked Fever more and more throughout the book as she became more like a person of her own age and began to realise that there is more to life than she had ever been taught.

She also unearths some truths about her past and family.

Apart from the main plot (Fever's life) there is a sub-plot which does entwine with her life. This is basically a story of racism and rebellion between the ‘homo sapiens’ and the ‘homo superiors’ (two slightly different races). The author uses this as another distraction for Fever and she has to struggle once again to regain her sense of self, whether she allows herself to be compassionate and caring or just rational. She also has to discover if she is just being used as a key to a whole bigger plot around her life.

There is another character I like called Charley, who is hired by an important  man to help him with his work. He too has to face a dilemma over whether to do what is right or to do what he is told; this shows his true personality.

I think this book is about the decisions we have to make as people, the big and the small, and our natural human reactions to them. We can’t really suppress our feelings about things however hard we try. I liked this book, it’s engaging and the characters were all easy to relate to. It was not a hard read as there were lots of exciting fast-paced sections and none of it was very boring. I would recommend this to people of most ages.