A really good story that combines some realistic elements of the wolf with a fantasy type story. A really good book for anyone that likes wolves and animal adventure stories.
A couple other good wolf fantasy books are: Promise of the Wolves and Secrets of the Wolves by: Dorothy Hearst. Both books are part of The Wolf Chronicles trilogy. Book three is: Spirit of the Wolves, which I have yet to read!
And for younger readers, or wolf fantasy lovers, the 6 book Wolves of the Beyond series by: Kathryn Lasky is also very good.