(From the publisher):
The Norse gods are in an uproar--Thor's hammer has been stolen! The goddess Freyja has foreseen that a human boy will help find the hammer; the Basset sails into the mortal world to find him. But when the Basset returns, it carries not one boy, but four--all of whom must change if they are to fulfill Freyja's prophecy and save the gods from destruction.
Original title: Thor's Hammer
Genre: Fiction→ Fantasy→ Saga, Myth, and Legend
Fiction→ Children & Young Adult→ Fantasy→ Fantasy Worlds
Fiction→ Children & Young Adult→ Fantasy→ Mythical Creatures