The North is a very old nation. Older than Equestria. An origin drenched in blood, but it has come to Equestria offering a hand of kinship. However, Celestia's personal experience with the wolves of the North may not give the two nations a chance.
Fluttershy has been bitten. She changes every full moon and she's not sure why. Something did this to her, and that something had a purpose. But what, and what will she do about it?