Wotan, Father of the Gods, brings together his son Siegmund and his twin sister Sieglinde. Not recognising one another, they fall in love. Siegmund is fated to be the hero who will regain the ring of the Nibelungen for Wotan. In the ensuing fight between Siegmund and Sieglinde’s husband, Hunding, Siegmund’s victory is guaranteed by the sword Nothung. However, Wotan’s wife, Fricka, demands that Siegmund die to atone for the sin of adultery. Wotan’s daughter, Brünnhilde, a Valkyrie maiden, is ordered to ensure Siegmund’s defeat. Yet touched by his love for Sieglinde, she disobeys Wotan and tries to save Siegmund. For this she is banished to the Valkyries’ Rock. Surrounded by an eternal fire, there she shall sleep until a fearless mortal passes through the flames and awakens her.