The primary antagonist is , the Irish god of love, youth, and poetic inspiration. In Hearne’s world, Aengus isn't a chubby cherub; he’s a vindictive, psychopathic Tuatha Dé Danann with a terrifying temper and a legion of followers. When Aengus tracks Atticus to modern-day Tempe, Arizona, the druid realizes he can no longer run. To survive, he must fight.

In a genre filled with tortured anti-heroes, Oberon provides genuine, laugh-out-loud relief. His running commentary on squirrels, his desire to be a “great hound of war,” and his philosophical debates about sausages ground the supernatural chaos in something purely joyful. He is the heart of the book.