Thor, the Norse god of thunder, is worse than a blowhard and a bully — he's ruined countless lives and killed scores of innocents. After centuries, Viking vampire Leif Helgarson is ready to get his vengeance, and he's asked his friend Atticus O'Sullivan, the last of the Druids, to help take down this Norse nightmare.One survival strategy has worked for Atticus for more than two thousand years: stay away from the guy with the lightning bolts. But things are heating up in Atticus's home base of Tempe, Arizona. There's a vampire turf war brewing, and Russian demon hunters who call themselves the Hammers of God are running rampant. Despite multiple warnings and portents of dire consequences, Atticus and Leif journey to the Norse plain of Asgard, where they team up with a werewolf, a sorcerer, and an army of frost giants for an epic showdown against vicious Valkyries, angry gods, and the hammer-wielding Thunder Thug himself.
After twelve years of secret training, Atticus O'Sullivan is finally ready to bind his apprentice, Granuaile, to the earth and double the number of Druids in the world. But on the eve of the ritual, the world that thought he was dead abruptly discovers that he's still alive, and they would much rather he return to the grave. Having no other choice, Atticus, his trusted Irish wolfhound, Oberon, and Granuaile travel to the base of Mount Olympus, where the Roman god Bacchus is anxious to take his sworn revenge — but he'll have to get in line behind an ancient vampire, a band of dark elves, and an old god of mischief, who all seem to have KILL THE DRUID at the top of their to-do lists.