Very cool idea for a plot. Although this book is pretty long, I finished it in two or three days (despite the need to do other, more useful, things).
The story is about the twelve signs of the Chinese Zodiac, with a person who represents each animal. A girl named Brenda discovers early in the book that she is the future Rat, and she has to help regain the memories of her father and other "animals" whose memories of their identities have been stolen. Brenda is forced into a battle she hadn't been aware of until just weeks before, and although only a "Rat-ling", she must help the twelve and the grandson of the original emperor.