In a world where two factions are on the constant brink of conflict, and humans are in the middle of the two fires, the prince of the Svaltàlfars, Fàfnir, lives in the underground kingdom of Nidavellir. Unlike the brothers Reginn and Oter, he does not aspire to the throne of his kingdom, and behaves like an ordinary citizen, which makes his father, King Hreidmarr, extraordinarily proud without his knowledge. But when Fàfnir is accused by his own brother of killing the King his father, and a mysterious ring awakens a monster so far locked inside him, his life will change forever, and he will have to decide whether to return to his homeland and stop the imminent war with the Liosàlfar, or give in to his dark side and bring to destruction everything he has loved so far.