My name is Magnus Chase. Two months ago I died fighting a fire giant and woke up in Hotel Valhalla as one of Odin's warriors. Time for a rest ? I wish. When I meet Otis, an informant with a lead on Thor's missing hammer, all I get is the name "Provincetown" before a wolf-masked assassin takes him out and warms me to stay away. Someone really doesn't want me to find the hammer, and even if I could it's rumoured to be underground, guarded by powerful magic. But the giant armies are on the move, preparing to invade. If I don't find it, they'll ravage the Nine Worlds, starting with the streets of Boston. There's just one person who could help. Someone who demands a very high price: the gods' worst enemy, Loki.