The Sigurd poems belong to a time prior to the introduction of Christianity, as is incontestably proved by the genuine heathen spirit that throughout pervades them. Their action is in the early days, when the gods walked upon earth and mixed themselves in human affairs. The real theme of the epic which the lays form is the mythical golden hoard, and with it the fated ring of the Nibelung, owned originally by the dwarf Andvari, from whom it is wrung by the gods in their extremity. Andvari curses it to its possessors, and it is cursed again by the gods who are forced to deliver it up to Hreidmar as blood-money for his son, whom Loki had slain. Fafnir and Regin, the brothers of the slain Ottur, demand of their father their share of the blood-fine, and when this is refused, Hreidmar is killed while asleep, and Regin is driven away by Fafnir, who then in the guise of a dragon lies upon the golden hoard to guard it. Egged on by Regin, Sigurd slays Fafnir, and Regin also when he learns that he intends treachery. Sigurd gives the ring of Andvari, taken from the hoard, to the Valkyrie Brynhild, as a pledge of betrothal; and when in the likeness of Gunnar the Nibelung,--having by wiles forgotten his former vows,--he rides to her through the fire, the ring is given back to him by Brynhild, who does not recognize him. The fatal ring is now given by Sigurd to his wife, Gudrun the Nibelung, who in a moment of anger shows it to Brynhild and taunts her with a recital of his history. Brynhild cannot bear to see the happiness of Gudrun, and does not rest until Sigurd is slain; and in slaying him, Guthorm, the youngest of the Nibelungs, is killed, struck down by the sword of the dying Sigurd. Brynhild, who will not outlive Sigurd, perishes on her own sword. Gudrun is subsequently, against her will, wedded to Atli the Hun. Gunnar and Hoegni, her brothers, the two remaining Nibelungs, are invited to visit Atli, when they are straightway fallen upon, their followers are killed, and they are bound. They are asked to give up the golden hoard, whose hiding-place was known to them alone; but Gunnar first demands the death of his brother Hoegni, and then triumphantly tells Atli that the treasure is forever hidden in the Rhine,--where, he only knows. He is cast into a serpent pit, and dies. Atli's sons and Gudrun's are slain by their mother, changed by the madness of grief at the slaughter of her brothers into an avenging Fury, and Atli himself and his men are burned in the hall. Carried then by the sea, into which she has hurled herself, Gudrun comes to the land of King Jonakr, who makes her his wife. Swanhild, the daughter of Sigurd and Gudrun, had been married to King Joermunrek, but coming under unjust suspicion, is trodden to death by horses; and Gudrun dies of a broken heart, with a prayer to Sigurd upon her lips. Last of all, the sons of Gudrun and Jonakr, who, incited by their mother, had been sent out to avenge their sister, are stoned to death;