Horus, a kid living in an unnamed Scandinavian/Eastern Europe culture of the Iron Age, recovers the Sword of the Sun from the rock giant Maug and learns from his dying father that he must return to his ancestral territory. In the process, he defends a village from the attacks of Grunwald, a warlord/ice demon and befriends the enigmatic Hilda, a lonely and beautiful girl who sings haunting songs (and who hides a terrible secret).