Non-specific spoilers below.
While parts of the book were entertaining and a few of the characters endearing, one big thing kept this book at a "3" rather than a "4" or a "5."
For me, Ms. Lackey is over-fond of the villain who takes over someone else's body/life. In thirty seconds, I can think of ten of her books that have the same theme, and I'm sure there are plenty more.
With that said, it's mostly a fun read, and the horrific parts are sufficiently shuddersome without being stomach-turning. It was a nice way to while away a snowy Saturday.