Gefialdr Underground

"Hm! Hmm-hmm!" Gefialdr exclaimed.
The man was never one for adventure. His reputation as a seer spread far and wide when he was young, and so he lived quite comfortably in the retinues of chieftains before settling at the Temple of Uppsala, where was trained in the ways of a gothi [priest] and his fame slowly grew.
When the snows proved unrelenting, the marshy plains leading from the river Fyri to his temple were thronged with desperate families. Burdened as they were by their children and their offerings, the pilgrims were easy prey for the Helbuar who moved without care of food or warmth. The gothi hung nine willing pilgrims in the sacred grove beside the temple as an offering to end the Great Winter, and countless animals, but the corpse-black things overran the Temple of Uppsala, the blood splattered on its hallowed idols a final offering of the gothi who attended them.
Gefialdr's last vision in the Temple drove him to find a hiding place among the blessed dead, for surely the helbuar would ignore given the easy slaughter above. So he fled at the sight of the helbuar, but not far - the twisting earth had drained the sacred spring near the temple's holiest yew, where men were drowned in sacrifice. He climbed into the pit, and when the tree roots became too sparse, he let himself fall into the darkness, trusting in what the gods showed him, and trusting that bones would break his fall. He instead fell onto solid ground after a blessedly brief fall, and saw torchlight in the distance.
He followed the light, though never found its source. Some artifice of the earth-dwelling dwarves must have illuminated the tunnel. Gefialdr eventually came into a large, round chamber, built in three layers of earth. Forges, no longer burning, were on each level. Ordered stacks of wood, iron, and other materials lay beside anvils, molds, and benches. And it was littered with dead.
Some were human, bound with iron rings around their neck as a symbol of their thralldom. They were dressed in the white robes of the men sacrificed in the spring. Others were not-quite-human. Roughly three-fifths the size of a man, but broad of shoulder and chest. They bore shirts of precious metal, fine rings of silver or gold, and metals of some hues Gefialdr had not seen before. Their broad, flat faces were pierced with gold, and they wore many gold bracelets. Where skin could be seen through the shining metal, it was black with soot. Neither master nor servant bore mark of violence, or any other sign of their doom. It was if the threads of their lives were simply - and unceremoniously - severed by the Norns.
Gefialdr pieced together than the men "drowned" in the spring, in fact, were drawn down by some force to this dwarven commune, and taken as slaves - probably to work the bellows. And the dwarves, their masters - worked the will of the gods while they listened to the prayers of the gothi, if for nothing but entertainment. Indeed, Gefialdr found many half-realized masterworks of these dwarves, but even more valuable, he found some of their secrets hewn into the rock. The script was difficult at first, but not unlike the runes used in casting sticks. Gefialdr read all he could, eating the simple food kept for the thralls. Miraculously, both food and slave did not rot or fester.
Now, he felt he could learn no more. The final slab he read recalled some secret formula of the dwarves for what they called eiterstal. He left the dwarven commune, choosing at random of the many tunnels that spread from the chamber.