It felt like it lacked something. I'm not sure what, but there is this nagging feeling. Maybe it's a lack of tension despite the constantly ongoing action. Maybe the fact it's a bit place-specific; while it paints an interesting picture of a rarely seen side of London, it felt like there was some inside joke I'm not getting because I'm unfamiliar with the place.
The world is unique, and so are the characters. The plot isn't. Still, it was an interesting read, definitely different from other books I've read. I'm not fond of series, but I wish this book had a sequel or was expanded. It felt like there was so much more and this story is but a small piece of it. Maybe that's what was missing.
It's a good book...if you don't mind rats.