Mortal Engines - Philip Reeve
This is the first in a quartet of books and I've been trying to get hold of it for a while, since I always seemed to see the next book in my local library and never this one!

The universe in which these books are set is one of a future Earth where various cities have been rebuilt in such a way that they can travel across land in search of prey, that prey being other cities whose resources they can recycle. In the case of Mortal Engines, the main city we're talking about is London which is under the control of the Guild of Engineers.

Our hero is an apprentice Historian, Tom Natsworthy, whose job it is to clean the exhibits in the museum, but who inadvertantly crosses paths with one Hester Shaw, who is very much an anti-hero. She has a vendetta against the Head Historian, who Tom idolises, because he was responsible for the murders of her parents and her own disfigurement - Tom finds himself left behind by London and reliant on Hester to find his way back to some kind of safety, but of course things are nothing like as simple as he has always been led to believe.

It's an intriguing premise, peopled with characters who seem very real, and I'm looking forward to seeing how the rest of the series works out. The next book in the quartet is Predator's Gold.