The saga of Sigurd, the Völsung, reaches its pivotal climax on the desolate Gnita-heath, a place where the air hung heavy with the scent of ancient greed and the sulfurous breath of the dragon Fafnir. Sigurd had been raised in the house of King Hjälprek, fostered by a man named Regin, a master smith of the dvergr (dwarf) race who possessed a mind as sharp as his tools and a heart twisted by centuries of resentment. Regin had long sought the hoard of gold that his brother, Fafnir, had stolen after murdering their father, Hreidmar. Fafnir, consumed by the curse of the ring Andvaranaut, had transformed into a monstrous serpent-dragon to guard the gold, and Regin lacked the physical strength to reclaim it himself. He had spent years molding Sigurd into a weapon, a hero of unparalleled strength who could accomplish the deed that Regin’s own cowardice prevented.
Regin had forged many swords for Sigurd, but the youth had broken every one of them upon a simple anvil, finding them unworthy of his lineage. It was only when Sigurd brought the shattered shards of Gram, the sword of his father Sigmund, that Regin was able to craft a blade of true power. Gram was a weapon of destiny, capable of cleaving an anvil to its base and slicing a lock of wool floating on a stream. With this sword in hand, Sigurd rode out to the heath, guided by Regin’s instructions to find the path where the dragon crawled to find water. Along the way, Sigurd was visited by an old man in a grey cloak—Odin in disguise—who advised him not to dig a single pit to hide in, but rather a series of trenches so that the dragon's torrential blood would not drown him when he struck from below.
As the sun began to set over the jagged rocks of the heath, the ground began to tremble. Fafnir was coming. The dragon’s movement was like the grinding of tectonic plates, his scales scraping against the stone with a sound like iron on iron. From his hiding place in the trench, Sigurd waited until the Great Worm passed directly overhead. With a cry of 'Gram!', he thrust the blade upward with all his might, piercing the soft underbelly of the beast and finding its heart. The dragon let out a roar that shook the foundations of the world, thrashing in its death throes. Sigurd leaped from the pit, standing before the dying monster. Fafnir, even in his final moments, was eloquent. He asked who the boy was and warned him of the curse of the gold. 'The sounding hoard and the glow-red gold,' Fafnir hissed, 'shall be thy death.' Sigurd, however, accepted his fate, for he believed that all men must die, and to die with glory and wealth was the highest path.
Once Fafnir fell silent and the life left his massive eyes, Regin emerged from the shadows where he had been hiding in terror. Seeing his brother dead, Regin’s grief and greed fought for dominance in his twisted soul. He approached Sigurd and, instead of thanking him, accused him of the murder of his kinsman. As a form of 'weregild' or blood-payment, Regin demanded that Sigurd take Fafnir’s heart and roast it for him. He claimed that eating the heart of such a powerful being would grant him wisdom and strength. Sigurd, bound by the codes of honor and the manipulation of his foster-father, agreed. He built a great fire and placed the heart on a wooden spit, turning it slowly as the fat sizzled and dripped into the flames.
As the meat cooked, Sigurd reached out to touch the heart to see if it was tender enough. A spurt of boiling dragon-fat splashed onto his thumb, searing the skin. In a natural, reflexive motion, Sigurd thrust his burned thumb into his mouth to soothe the pain. The moment the dragon’s blood touched his tongue, the world was irrevocably altered. The silence of the forest was replaced by a cacophony of voices—not human voices, but the sharp, rhythmic chirping of the birds in the trees above. To his astonishment, Sigurd realized he understood every word they were saying. These were the seven nuthatches (or titmice, in some tellings) of the forest, and they were discussing his very fate.