Viking children Røskva and Tjalfe embark on an adventurous journey from Midgard to Valhalla with the gods Thor and Loki. Life in Valhalla, however, turns out to be threatened by the dreaded Fenrir wolf and the god's barbaric archenemies, the Jotnar. Side by side with the gods, the two children must fight to save Valhalla from the end of the world--Ragnarok.