The young Frode is trained by the one-armed warrior Knut to succeed his father Agnar as Viking leader. Agnar is a brave man with a big heart and a great sense of humor. Frode seems to be just like him in every way. But Frode's mother is very different. She is strict and cruel. That's why the twelve-year-old Hisse, a young slave from Frisia, is terrified of her. When Agnar dies after a battle in the land of the Franks, Hisse is chosen to follow him to Valhalla on a burning Viking ship. However, Frode is very fond of Hisse and devises a life-threatening plan to save her from that cruel death...