Act I

As a storm rages, Siegmund the Wälsung, exhausted from pursuit by enemies in the forest, stumbles into a house for shelter. Sieglinde finds the stranger lying by the hearth, and the two feel an immediate attraction. But they are soon interrupted by Sieglinde’s husband, Hunding, who asks the stranger who he is. Calling himself ‘Woe-full’, Siegmund tells of a life filled with sorrow, only to learn that Hunding is a kinsman of his foes. Hunding challenges the stranger to combat the next day. Left alone, Siegmund calls on his father, Wälse, for the sword he once promised him. Sieglinde reappears, having given Hunding a sleeping potion. She tells of her wedding, at which a one-eyed stranger thrust into a tree a sword that thereafter resisted every effort to pull it out. Sieglinde confesses her unhappiness to Siegmund, whereupon he ardently embraces her and vows to free her from her forced marriage to Hunding. Siegmund compares their feeling to the marriage of love and spring. Sieglinde asks if his father was really ‘Wolf’, as he said earlier. When Siegmund gives his father’s name as Wälse instead, Sieglinde knows for certain that he is the Wälsung for whom the sword is intended. She tells him that he is her twin brother and Siegmund draws the sword from the tree.

Act II

Wotan instructs his daughter Brünnhilde to protect Siegmund in the impending fight with Hunding. Brünnhilde warns Wotan that his wife, Fricka, the guardian of marriage, is approaching. Fricka arrives demanding the punishment of Siegmund and Sieglinde, who have committed adultery and incest. She knows that Wotan, disguised as the mortal man Wälse, fathered Siegmund and Sieglinde. Wotan protests that he requires a free hero (i.e. one not ruled by him) to aid his plans, but Fricka retorts that Siegmund is not a free hero. He is a pawn in a game invented by Wotan, who is himself severely compromised by his promiscuity. Backed into a corner, Wotan agrees to forbid Brünnhilde to let Siegmund win the battle against Hunding, ensuring the death of his beloved child Siegmund.

Siegmund and Sieglinde enter. Sieglinde faints in guilt and exhaustion. Brünnhilde approaches Siegmund and tells him of his impending death. Siegmund refuses to follow Brünnhilde to Valhalla when she tells him Sieglinde cannot accompany him there. He draws his sword and threatens to kill both Sieglinde and himself. Impressed by his passionate love, Brünnhilde relents and agrees to grant victory to Siegmund instead of Hunding.

Hunding arrives and attacks Siegmund. Brünnhilde urges Siegmund to trust in his sword ‘Nothung’ but Wotan appears and shatters Nothung with his spear. While Siegmund is disarmed Hunding stabs him to death. Wotan looks down on Siegmund’s body, grieving, while Brünnhilde gathers up the fragments of Nothung and flees with Sieglinde. Wotan strikes Hunding dead with a dismissive gesture, and angrily sets out in pursuit of his disobedient daughter.

Act III

The Valkyries, preparing slain heroes destined for Valhalla, are surprised at the arrival of their sister, Brünnhilde, with Sieglinde. When they hear she is fleeing Wotan’s wrath, they refuse to protect her. Brünnhilde tells Sieglinde that she bears Siegmund’s child. She receives the pieces of the sword from Brünnhilde and thanks her rescuer as she rushes off into the forest to hide near Fafner’s cave, a place safe from Wotan. When the god appears, he sentences Brünnhilde to become a mortal woman. Brünnhilde pleads that in disobeying his orders she was really doing what he wished. Wotan will not relent: she must lie in sleep, vulnerable to the first man who finds her. But as his anger abates she asks the favour of being surrounded in sleep by a wall of fire that only the bravest hero can penetrate. Wotan kisses Brünnhilde’s eyes with sleep and mortality before summoning Loge, the spirit of fire, to encircle the rock.