One day, while Siegfried and his wife were on a visit to the Burgundian court, the two queens fell to quarrelling on the ques tion of precedence, not in a river but on the steps of the cathedral (Avent. xiv.). Kriemhild was taunted with being the wife of Gunther's vassal; whereupon, in wrath, she showed Brunhild the ring and the golden girdle taken by Siegfried, proof that Siegfried, not Gunther, had won Brunhild. So far the story is essentially the same as that in the V olsungasaga; but now the plot changes. Brunhild drops out, becoming a figure altogether subordinate and shadowy. The death of Siegfried is compassed, not by her, but by the "grim" Hagen, Gunther's faithful henchman, who thinks the glory of his master unduly overshadowed by that of his vassal. Hagen easily pursuades the weak Gunther that the supposed insult to his honour can only be wiped out in Siegfried's blood; he worms the secret of the hero's vulnerable spot out of Kriem hild on pretence of shielding him from harm (Avent. xv.) and then arranges a great hunt in the forest, so that he may slay him when off his guard. The 16th Aventiure describing this hunt and the murder of Siegfried is perhaps the most powerful scene in all mediaeval epic. When the hunters sat down to feast, it was found that the wine had been forgotten. Hagen thereupon pro posed that they should race to a spring some way off in the forest. Siegfried readily agreed, and though handicapped by carrying shield, sword and spear, easily reached the goal first, but waited, with his customary courtesy, until the king had arrived and drunk before slaking his own thirst. Then, laying aside his arms, he stooped and drank. Hagen, seizing the spear, thrust it through the spot marked by Kriemhild on Siegfried's surcoat. The hero sprang up and, finding that his sword had been removed, attacked Hagen with his shield.
Then reproaching them for their cowardice and treachery, Sieg fried fell dying "amid the flowers" while the knights gathered round lamenting. The whole spirit of this scene is primitive Teutonic rather than mediaeval. The same is true, indeed, of the whole of the rest of the poem. Siegfried, to be sure, is buried with Catholic rites; but Kriemhild, while praying for his soul like a good Christian, plots horrible vengeance like her pagan proto type. Mistress now of the Nibelungen hoard, she sought to win a following by lavish largesses ; but this Hagen frustrated by seizing the treasure, with the consent of the kings, and sinking it in the Rhine, all taking an oath never to reveal its hiding-place (Avent. xix.). At last, however, after 13 years, Kriemhild's chance came, with a proposal of marriage from Etzel (Attila) king of the Huns, which she accepted on condition that he would help her to vengeance (Avent. xx.). Then more years passed; old feuds seemed to be forgotten ; and the Burgundian kings, in spite of Hagen's warnings, accepted their sister's invitation to visit her court (Avent. xxiii.–xxiv.).
The journey of the Burgundians into Hunland is described by the poet at great length (Avent. xxv.–xxvii.). From this point on ward the story is dominated by the figure of the grim Hagen, who, twitted with cowardice and his advice spurned, is determined that there shall be no turning back and that they shall go through with it to the bitter end. With his own hands he ferries the host over the Danube and then destroys the boat, so that there may be no return. At Attila's court (Avent. xxviii.) it is again Hagen who provokes the catastrophe by taunting Kriemhild when she asks him if he has brought with him the hoard of the Nibelungs : "The devil's what I bring you !" Hagen then replied, "What with this heavy harness and my shield beside, I had enough to carry ; this helmet bright I brought ; My sword is in my right hand, and that, be sure, I bring you not !" The sword was Siegfried's. It is Hagen, too, who after the first onslaught of the Huns, strikes off the head of Ortlieb, the son of Etzel and Kriemhild, and who, amid the smoke and carnage of the burning hall, bids the Burgundians drink blood if they are thirsty.
But for all their prowess, after a prolonged struggle (Avent. xxix.–xxxvii.) the Burgundians were at last overwhelmed. Most of the chief figures of heroic saga had come up against them; Attila, Hildebrand, the Ostrogoth Theodoric (Dietrich von Bern). To the last named even Hagen armed with Siegfried's sword had to yield (Avent. xxxviii.). Kriemhild came to him as he lay in bonds and demanded the Nibelung treasure. He refused to reveal its hiding place so long as Gunther, also a prisoner, should live. Gunther was accordingly slain by the queen's orders and his head was brought to Hagen, who cried out when he saw it that all had been accomplished as he had foretold : "Now none knows where the hoard is save God and I alone: That to thee, devil-woman, shall nevermore be known !" Whereupon Kriemhild slew him with Siegfried's sword. But Kriemhild was not destined, like Gudrun, to set out on further adventures. Hildebrand, horrified at her deed, sprang forward and cut her to pieces with his sword.
In sorrow now was ended the king's high holiday, As ever joy in sorrow ends and must end alway.
To some mss. of the Nibelungenlied is added a supplementary poem called the Klage or Lament, a sequel of 2,16o short-line couplets, describing the lament of the survivors—notably Etzel —over the slain, the burying of the dead, and the carrying of the news to the countries of the Burgundians and others. At the end it is stated that the story was written down, at the corn mand of Bishop Pilgrim of Passau, by a writer named Konrad (Kuonrat) in Latin and that it had since been sung (geticlitet) often in the German tongue.