From back of book: Atticus O'Sullivan, last of the Druids, lives peacefully in Arizona, shape-shifting in his spare time to hunt with his Irish wolfhound. His neighbors think that this handsome, witty, tattooed Irish dude is about twenty-one years old--when in actuality, he's twenty-one centuries old. Atticus draws his power from the earth and wields a magical sword. Unfortunately, a very angry Celtic god wants that sword, and he's hounded Atticus for generations. To thwart this determined deity, Atticus will need all the power he can muster to deliver himself from evil.

(Source: Del Rey)