I change narrative style a little bit here. Let me know what you think of it.
Odin would have left Billing's Dun at dawn the next morning, shamed and angry, had refugees from the neighboring dun – that of Billing's brother – not woken them before the sun had rightly begun its rising.
Riders, they gasped. Riders from the North. Dark as Death with swords of flame who razed the thatch of their dun above their heads in smoke. No sign was left behind them. They vanished as a morning mist.
What did they want, Billing raged. What had they taken.
They took nothing but lives. Left nothing but ash.
What had caused this.
He didn't know. He didn't know. Nothing had caused it. They were unprepared.
Odin stepped in. These attacks, he had heard of such attacks in his travels.
Billing looked on him with a newfound interest. He waved for the distraught refugees to be led by his daughters, Saga, Frigga and Gefjun, to the recesses of the Hall, to have their wounds cared for and to be comforted.
The eldest and youngest obeyed. Frigga remained, to Odin's disgust, her face taught, eyes alight. Her hands were tight on the back of a chair behind which she stood.
Billing wanted to know of these creatures.
Castlings, Odin promised.
Frigga watched him, rapt and anxious.
Odin did not look again at her.
Creatures of fire and ash, he said. All but indestructible. Cast by a dragon out of the Nidaveil. He'd seen their like among the forests of the Nidavellir.
Billing scoffed. The Nidavell and Vanir were rivals time-out-of-mind.
Odin told how he had been wandering among the few towns that pocked the surface of that subterranean realm and how the dragon Vrending had roused herself and working her strange magic – magic chosen to devour the land piece by piece through the flame and ash of her castlings.
The first thing to be done, he said, was to protect the dun with water. If they had any stormbringer, such a one should be summoned.
Billing looked to his daughter.
She shook her head. She told her father she had but little skill commanding the storm, and she knew of none other who did.
Then, Odin told them, they would have to be ready. Armed with water to douse the flames as the attackers rode through. To salvage what they could of the buildings.
"What then?" Frigga asked. "Surely the dragon will only be angered and will come back."
Billing looked to him.
"The dragon must be slain," Odin said, "either that, or persuaded to go back to sleep."
Frigga scoffed that such a thing as persuading a dragon could be thought of.
"They speak," Odin told her loftily. "Should they not also think?"
Frigga folded her arms, "You know little of men," she answered.
Billing spread his hands. "We have little ability, Bolverk, to do this thing you ask. We have no blade of the strength necessary to slay the manner of beast you describe. Unless you have ability you have yet to reveal to us?"
"I do not."
"Father," Frigga came nearer him. Stopped beside his chair with her hands on the arm of it.
The old chieftain closed his eyes. Certain of what it was he would be hearing.
Odin knew what it was she would ask. It was preposterous, and he smirked, soothed that at least she should not have that which she desired.
"I have much skill in the craft of my mother. There is nothing else the wise-women here may teach me, and none of your men-at-arms either. I would face this beast. I have slain my share on the hunts –"
"This is not a wyrm as those who prey on cattle, Daughter."
"This I know." Frigga said. "But you yourself just said that we possess no weapon to end this threat. Perhaps magic might serve where a blade does not."
"And if not?"
"Bolverk believes the dragon can be reasoned with. One way or another, Father –"
"And if not, Frigga?"
She drew herself up. "Then I die to save my people. You have two daughters more. Saga already will lead your line, and Gefjon is a good daughter. Both," she touched his arm, "less strain on you than I."
The old chieftain eyed her fondly, "Neither more dear," he said.
Giving a slight smile she inclined her head.
"And neither," the old chieftain straightened, "more stubborn. You will follow this path with my leave or no, will you not, Daughter?"
Giving a soft chuckle, Billing rested one hand on his daughter's cheek. He turned to where Odin stood across the room. "An honest daughter is a thing to be prized above gold. Remember that in your future days, Bolverk."
Odin breathed a scornful laugh. He looked away, impatient and uncomfortable with this exchange. He had not, however, been dismissed by the chieftain. Some regulations were kept, even among the Vanir, and he knew to leave without dismissal was unwise.
Billing put one hand behind his daughter's neck and rested his forehead to hers. "My strength and my blessing go with you, Girl," he said softly. "Norn speed and blessing on your quest. My blessing return to me if you do not bow to my one condition."
"Bolverk will accompany you."
She leapt back as though he'd struck her, "Father! You can't –"
Odin was as little pleased as she. But he could see how little this man was to be placated. He shut his teeth.
"He alone knows what manner of thing this is," Billing explained quietly. "And in the days he has dwelt with us he has showed himself a hunter skilled both in tracking and in slaying the kill. These are traits that will be invaluable to your quest. And it was he who brought up the notion of reasoning with the beast, once it is found. I will not be swayed. Either he goes with you or you remain under my personal guard until some other had dispatched the creature."