The film opens with a rainbow showing over the land and Siegfried shaping a sword. His work is inspected by Mime who uses the sword to cut a feather. Mime deems Siegfried masterful in his craft, and with nothing left to teach him tells him to go home. Siegfried then hears the story of the beautiful Kriemhild the sister of King Gunther and he desires to instead go to win her heart. He sets off and soon encounters a fire-breathing dragon which he slays with his sword. He hears a song from a bird that tells him to bathe in the blood of the dragon and he will become invincible, neither sword nor spear will penetrate him.
Siegfried then encounters the King of the Dwarves who attempts to kill him, but Siegfried subdues him and takes off his invisibility mask. The Dwarf King begs him to spare his life and offers him his treasure as reward along with the mask, but the King attempts to kill Siegfried and is killed in the process. The King curses the treasure before he dies.
Then, Siegfried arrives at the palace of King Gunther where he asks for the hand of Kriemhild in marriage. The King agrees to let him marry his sister on the condition that he help him win Brunhild as his wife by working with him to pass the three tests she set out for any suitor. If they fail they will be executed.
Siegfried uses the mask to make himself invisible and helps King Gunther defeat Brunhild in the contests. She goes with the King, but knows deep down that he is not the one who defeated her. Once they arrive back at King Gunther's palace Siegfried agrees to put on the mask which allows him to become anyone he chooses, and becomes the King. He then enters Brunhild's chambers and subdues her into believing he is her suitor by overpowering her. In the process he takes her armlet from her and keeps it.
Siegfried, a half a year later, discovers Kriemhild with Brunhild's armlet on, and tells her never to let a human eye see it for it will expose the King as a liar. But, Brunhild soon after demands that Kriemhild walk behind her into the temple as she is now merely a wife of a vassal and she is the Queen. This infuriates Kriemhild and she exposes the armlet to Brunhild who immediately demands that Siegfried be killed as he took her maidenhood the night he struggled with her as King Gunther. Thus, King Gunther and his royal officer, Hagen von Tronje conspire to murder Siegfried during a hunt they have planned.
Hagen convinces Kriemhild to expose Siegfried's weakest spot on his body, he tells her it is to protect him. She believes the man to be noble and true and agrees to mark his body with a cross in his weakest spot. After the hunt is over Hagen challenges Siegfried to a race to a spring and When Siegfried in drinking from the spring Hagen sticks him with his spear.
Brunhild then confesses that she lied about Siegfried taking her maidenhood. That she said it so that she could get revenge on King Gunther for deceiving her. Kriemhild, wants revenge on Hagen for murdering her husband but her brother is complicit in his murder and protects Hagen. Kriemhild then vows to get revenge against Hagen. And Brunhild commits suicide at the feet of the corpse of Siegfried as the film ends, her last act of disobedience.
