Richard Wagner (1813-1883) wrote the music and libretto of Die Walküre (The Valkyrie), the second of four operas in Der Ring des Nibelungen (The Ring of the Nibelungs), a continuing story based on myths. In the first opera, the evil dwarf Alberich vies with Wotan, king of the gods, for possession of a golden ring empowering its wearer to rule the world. But the giant Fafner instead gains control of the ring. In Die Walküre, Wotan leaves to his earthly son, Siegmund, the task of recovering the ring, thereby preventing Alberich from seizing it first and using its power to destroy the gods. When Die Walküre opens, Siegmund is fleeing enemies and takes refuge at night in the dwelling of Sieglinde and her husband, Hunding. Because Siegmund's enemies are Hunding's friends, Hunding challenges Siegmund to a morning duel. While Hunding sleeps, Siegmund and Sieglinde discover that they are brothers and sisters, fall in love, and run off. Fricka -- the goddess of marriage -- demands that her husband, Wotan, punish Siegmund for enticing Sieglinde into incest. Wotan at first refuses. But under Fricka's nagging, he promises to intervene in the duel on Hunding's behalf. When Wotan's daughter Brünnhilde, a warrior maiden known as a Valkyrie, implores him to spare Siegmund, Wotan angrily refuses and forbids her to assist Siegmund. But headstrong Brünnhilde defies him and attends Siegmund during the duel. It is for naught. Wotan is there, too, and enables Hunding to slay Siegmund. Wotan then banishes Brünnhilde for her disobedience. She is to be cast into a deep sleep on a mountainside. However, Wotan agrees to create a ring of protective fire around her until a hero discovers and awakens her. In a touching final scene, father and daughter embrace and bid goodbye.