When Gunther returned with Brünhilde to the Gibichungs' Hall, great preparations were made to celebrate the two marriages in splendid state, and all the vassals and warriors quickly assembled to join in the revels.
All this time Brünhilde had remained submissive and downcast; but now, on entering the Hall with Gunther and finding herself confronted by Siegfried, who led Gudrun by the hand, she started violently and gazed on him with utter astonishment. Suddenly observing the magic Ring upon his finger, the true identity of the bold wooer who had intruded upon her rocky fastness flashed across her mind, and, full of furious anger at the discovery, she announced to all the company that she had been betrayed, and that Siegfried, in his wooing of her in disguise, had dishonoured their King.
Siegfried fearlessly defended himself, declaring that he had been loyal to his trust; but his explanations were designedly confounded by Hagen, who, for his own evil purposes, used his cunning wit to persuade all that the great hero had indeed acted as a base traitor.
Siegfried, however, having a clear conscience, still declared his innocence; and taking the hand of Gudrun, whom he now loved passionately owing to the effect of the love-potion, he led her gaily to join in the revels, followed by most of the company.
But Brünhilde and Gunther remained in their places, overcome with indignation, still believing Siegfried to be false; and seeing them alone, Hagen joined them, and with cunning words strengthened their suspicions and persuaded them that it was their duty to avenge themselves for the ill that had been done them. He at last obtained their consent to the murder of Siegfried, which he agreed to carry out himself at a hunting party next day; and having arranged this, they rejoined the revellers, and the wedding rejoicings went forward once more.
Next day, a grand royal hunt was organised, and Siegfried, in eager pursuit of prey, found himself at one time alone on the bank of the river. As he stood there a moment, gazing into the water, the three lovely Rhine maidens, Flosshildr, Woglinda, and Wellgunda, swam towards the shore and gave him glad greeting, knowing that this was the great hero who now possessed their long-lost treasure; and in coaxing tones they entreated him to restore the magic Ring to them.
Siegfried, however, refused to listen to their pleadings, even when the nymphs told him that if he retained it longer, the talisman would quickly bring death upon him; and as the Rhine maidens swam away disconsolately, he laughed aloud at their warning.
At that moment, Gunther, Hagen, and the rest of the hunting party joined him, and sitting down to rest upon the river bank, the huntsmen began to feast and make merry together. To amuse his new friends, Siegfried began to tell them the story of his life and adventures; but just as he was relating how he had scaled the fire-encircled mountain, Hagen crept softly forward and suddenly stabbed him in the back with his hunting-spear, announcing to the dismayed onlookers that the deed was done in retribution for the hero's betrayal of their King.
Siegfried sank to the ground immediately; and the effect of the magic potion of forgetfulness waning as his life-blood welled forth, all his old love for the beautiful Valkyrie he had so innocently betrayed returned to bless his last moments, and with Brünhilde's name upon his lips, he died.
The dead hero's body was quickly borne back to the royal Hall; and when the fair Gudrun beheld the lifeless form of her husband of a day, she fell senseless to the ground, overcome by despair.