It's the Viking era. The hero Angantyr has fallen. In his grave, he has taken with him the magical sword Tirfing, a sword that never misses to kill the enemy. His daughter Hervor needs the sword to protect herself from the cruel world of the Vikings.From his grave, Angantyr, who had no sons, demands that his daughter forever must appear as a man in order to retrieve and use the sword. Hervor dresses as the warrior Hervardur, receives the sword, which makes him/her an always unbeatable hero on the battlefields. However, the disguise will eventually prove to be her undoing.A love triangle develops between Hervardur and Vidar, "his" brother-in-arms who, in his way, is in love with Hervor/Hervardur, and Vidar's sister Gullväg, who has fallen in love with the hero Hervardur, not knowing that he, in fact, is a woman.Gullväg is courted by the three kings Gestur, Svasur, and Harald. Encouraged by her father, King Gudmundur, Gullväg asks three riddles to be solved by the courting cavaliers. She will marry the one who can solve them all. But she is, in fact, in love with Hervardur, who succeeds in solving the riddles to Gullväg's joy.However, Hervardur must (for obvious reasons) reject Gullväg, which makes Vidar furious, meaning that this is an unforgivable insult to his family. He therefore challenges Hervardur to a duel, whereupon he is killed by the invincible sword Tirfing.Hervardur is proclaimed an outlaw by King Gudmundur. Brokenhearted, Hervardur tells Gullväg of her true origin and once again seeks out her father's grave, returns the sword Tirfing, and dies.