Ragnarök: The Breaking of Helheim (Ragnarök: The Breaking of Helheim #6)

Thor races to reach the rim of the dead lands and escape the lethal vengeance of Hel, pursued by the beasts of Helheim and the numberless dead. With his destruction almost upon him, the God of Thunder gathers the fate of all of Helheim into his gauntleted hands as Mjolnir, the greatest weapon of the gods, speaks in a voice of thunder across the Dusklands.