In the ancient days of the world, when the boundaries between the realms of gods and giants were thin and fraught with peril, three of the highest Æsir—Odin the All-Father, Hœnir the silent, and Loki the cunning—set out on a journey far from the golden gates of Asgard. They traveled through desolate heaths and rugged mountains, eventually finding themselves in a land where the earth offered little sustenance. As the sun began to dip behind the jagged peaks of Jötunheimr, the gods felt the gnawing bite of hunger. In a valley below, they spotted a herd of oxen grazing peacefully. Driven by necessity, they slaughtered one of the beasts and set it over a great pit of fire to roast. Yet, as the hours passed and the flames roared, the meat remained as raw and bloody as the moment it was butchered. The gods were perplexed, for the fire was hot and the wood dry, but some unseen force seemed to be shielding the flesh from the heat.
From the branches of a towering oak tree above them, a voice boomed with a chilling, metallic resonance. 'The meat will not cook unless you grant me a share,' the voice declared. Looking up, the gods beheld a massive eagle, its wingspan wide enough to cast a shadow over the entire camp, and its eyes burning with a cruel, ancient intelligence. This was no mere bird, but the giant Thjazi, who had donned his eagle skin to mock the travelers. Hungry and weary, the gods agreed to his terms. The eagle descended, and with a single sweep of its massive talons, it seized the two hindquarters and both shoulders of the ox, leaving the gods with nothing but the offal. Loki, ever the most volatile of the trio, was consumed by rage at this insolence. He seized a heavy branch from the ground and struck at the bird with all his might as it attempted to fly away.
However, Thjazi was a master of enchantments. As the branch struck the eagle’s back, it did not bounce off; instead, it became magically fused to the giant's feathers. Loki found to his horror that his hands were stuck fast to the wood. With a powerful beat of his wings, Thjazi took to the sky, dragging the screaming Loki behind him. The giant flew low over the landscape, intentionally dragging Loki through the sharpest thorns, against the hardest granite crags, and through the freezing waters of mountain streams. Loki’s limbs felt as though they were being torn from his torso, and he begged for mercy, offering anything in exchange for his release. Thjazi, seeing his opportunity, demanded a price that would strike at the very heart of the gods: he wanted Idunn, the goddess of youth, and her golden apples that preserved the Æsir's immortality.
Bound by his pain and the fear of death, Loki swore a binding oath to deliver Idunn to the giant. Upon his return to Asgard, the trickster waited for the perfect moment. He approached Idunn in her private garden and, with a silver tongue, told her of a forest just outside the walls of Asgard where he had found apples even more wondrous than her own. He urged her to bring her basket so they might compare the fruits. Trusting her kinsman, Idunn followed him beyond the safety of the divine ramparts. No sooner had they stepped into the deep woods than the shadow of Thjazi’s eagle form fell upon them. The giant swooped down, snatched the goddess and her apples in his claws, and soared away to his fortress of Þrymheimr in the highest peaks of the mountains.
In Asgard, the consequences were immediate and devastating. Without the daily consumption of Idunn’s apples, the gods began to wither. Their hair turned the color of winter frost, their skin wrinkled like dried parchment, and the strength fled from their limbs. Even Odin felt the weight of the ages pressing down upon his spirit. A council was called, and the gods, though frail, managed to piece together the evidence. The last time Idunn had been seen, she was walking with Loki. They seized the trickster and threatened him with the most agonizing tortures if he did not find a way to restore the goddess. Terrified, Loki begged Freyja for her falcon cloak, which allowed the wearer to take the form of a bird of prey. He promised to fly to Jötunheimr and bring Idunn back, or die in the attempt.
Loki flew north, a lone falcon against a sky of leaden clouds. He reached Þrymheimr while Thjazi was out on the sea fishing, leaving Idunn alone in the cold halls. Using his magic, Loki transformed the goddess into a single hazelnut, which he grasped firmly in his talons before taking flight back toward Asgard. When Thjazi returned and found his captive gone, his roar shook the mountains. He donned his eagle skin and took to the air, his massive wings creating a sound like a coming hurricane. Because he was a giant in eagle form, his flight was faster and more powerful than Loki’s falcon form. As they crossed the final leagues toward Asgard, the gods standing on the walls could see the falcon straining for speed, with the shadow of the great eagle looming directly behind him, closing the gap with every second.