The god of thunder Thor and his companion Loke take the two Viking children, Tjalfe and Røskva, across the rainbow bridge to visit the legendary Asgard's gods and heroes. Here Tjalfe and Røskva meet Quark, a troublemaker of a giant, and with him they revolt against the tyranny of the adults and travel to the woods to build a wooden hut where they can live in peace. But Thor discovers their hiding place and forces them on a journey to the land of the giants, where they are swirled into a fight between gods and giants.