In the midst of a deep snowfall, Loki returns to get his vengeance on Arthur. In the months since they previously met, the trickster God has been assembling a deadly army of wolves and he intends to take the world once and for all. Many traps await Arthur on the way. Who or what is Fenrir? Who is the new girl in the class and why is she so interested in Arthur? What does Loki want that’s in the National Museum? And how can Arthur and Ash explain their new Viking friend to Stace?