The stairs to the Vault were older than the palace above them.
A single Einherjar led Arthur down, past the council galleries and the long halls of tribute, down a stair that narrowed and darkened the further it went, until the gold of Asgard gave way to plain worked stone and the air turned cold and old. The guard stopped at a door he did not open, bowed, and withdrew.
The door knew Arthur was coming. It swung inward on its own.
The Vault.
Arthur had never set foot in the Vault, in all his years coming to Asgard. Not for lack of means. There was little in this realm his magic could not have walked him into unseen, and the deepest room in Odin's kingdom would have been a pleasant afternoon's work. What kept him out was simpler than that. Friendship. A friendship he had no intention of spending on a moment's curiosity, and an alliance with a proud people that would not have survived a guest rifling through their secrets in the dark.
So he had stayed out. And now, here he was, invited, by the one man who could open the door without a key.
The chamber was vast and dim, lined on both sides with containment fields that hummed low beneath the silence. Arthur knew some of what they held. The Casket of Ancient Winters, breathing its slow cold behind a wall of light. The Eternal Flame, banked and waiting. And the empty pedestals, more of them than there should have been, the careful gaps where something had been taken away and never spoken of again.
Odin stood at the far end, beside one of the empty ones.
He was not in armour. He wore a plain grey robe, and Gungnir leaned against the wall beside him, untouched. Stripped of the gold and the one-eyed majesty, he looked exactly like what he was. A very old man, in a very old room, surrounded by the weapons of wars he had already won.
He did not turn. He let Arthur cross the cold floor and come to a stop, and let the silence stretch.
It was a test. Arthur understood that quickly enough. The All-Father had not brought him to the deepest room in his kingdom to put him at ease. He had brought him down into the dark, alone, turned his back, and now he waited to see what the mortal did with the quiet. Whether he would fill it. Whether he would shift, or clear his throat, or offer some small bow to remind them both whose realm this was.
Arthur did none of it. He stood easy in the cold and waited the old god out.
The seconds stretched into minutes. Neither of them moved an inch.
"You do not fidget," Odin said at last, still without turning around. "Most do, down here. Kings and seasoned warriors both. Something about a room full of dead men's weapons makes a man desperately want to prove he is still alive." He turned slowly now, and the single, ancient eye found Arthur and measured him. "You just stand there. Unimpressed."
"Should I be?"
"Oh." The white brow rose a fraction. "Most men would be."
"I think my vault is more impressive than this one."
"A bold claim."
"I have had time to accumulate a few things."
"You are very sure of yourself, wizard." Odin's voice was dry. "For a man whose whole life I could sit through without once rising from my chair."
"You could," Arthur agreed. "But not a life you'd want to. The interesting parts rarely happen where anyone can comfortably see them."
Something moved at the corner of Odin's mouth. Not quite a smile. The place where a smile used to be.
"Honest," he said. "And unafraid, which is the rarer of the two. I have known gods who could manage neither in this room." The eye held him. "Good. I did not call you here to be flattered, and I did not call you here to be feared. I have had five thousand years of both, and they weigh the same in the end. Nothing." He glanced at the cold around them. "Forgive the setting. I think more clearly down here. Up there I am the All-Father, who is certain of everything. Down here I am only the man who has to live with what the All-Father decided." A worn note. "It is more honest. I have come to prefer honesty. A weakness of old age."
It was, Arthur thought, the first thing he had ever heard Odin say that did not sound like a decree.
"Then I'll give you the same," Arthur said. "It'll save us both time."
"Good." The eye settled on him. "Then let us talk about my son."
"Which one?"
"The one you bound in fragile, mortal flesh."
"He earned it," Arthur said, without a trace of apology. "He threatened my children."
"He did. And men have died screaming for far less." Odin studied him. "And yet you left him breathing. The enchantment you wove over him is an incredibly elegant piece of work. You gave my son the chance to learn the weight of a fragile life, rather than ending him for his crimes." The old voice was quiet. "The King of Asgard thanks you for the restraint. And a father thanks you for the mercy."
"Don't thank me," Arthur said flatly. "Thank Thanos. If Loki had been himself when he came after my family, I don't know what I would have done."
The temperature of the room did not change. But something in Odin's face did.
"The Mad Titan," Odin said slowly. "Thanos." He turned the name over like a stone he had hoped not to find under his foot. "He has grown bold. For an age he kept clear of the realms under Asgard's protection. He took his harvests in the dark places, the worlds no one watched, and he was careful never to cross into Asgard's light. He knew the cost." The eye sharpened. "And now he reaches out and takes my son for a puppet, and throws an army at Midgard, which sits squarely beneath Asgard's shield. He has stopped being careful. And Midgard, Hayes, is now firmly among the things he means to take."
"Let him come," Arthur said, his voice cold. "It will be his last battle."
Odin looked at him for a long moment.
"Is that your power talking?" he asked quietly. "Or the stones?"
Arthur's eyes narrowed, just slightly.
"Do not look so surprised, wizard." A faint, humorless smile touched the old mouth. "I was intimately close to the Stones in my prime. I can feel their resonance on you now. Lingering. Cosmic. Radiating off your skin like heat off a forge." The eye held him. "I will not tell you what to do with them. You are not my subject, and I am long past issuing decrees the universe ignores. But I will say this, as one man who has stood near such things to another. Do not gather them together. The Titan is the largest thing that hunts them. He is not the only one. And there are things that wake when the stones draw near one another. Things I did not dare disturb even in my strength."
"I'll weigh it," Arthur said, and did not promise more.
"That is all an old man can ask." Odin let it settle, and then something colder came into his voice. Quieter. Almost regretful. "But hear me, Hayes. You and the Mad Titan are not so different. Two beings on the same road. Gathering the stones into your hands. Reaching for the same cold thing behind the veil."
Something shifted behind Arthur's eyes. He had not put that together. The stones, and the death energy. Without meaning to, he and Thanos were walking the same path.
"I understand," Arthur said quietly, his mind already racing.
"I wonder if you do." Odin began to circle him, slow, the single eye assessing him like a weapon on an anvil. "I can see your power, Arthur Hayes. Even with external help, I did not think a mortal could ever reach such staggering levels of raw power, and in such an incredibly short time." He stopped. "But that short time is also your greatest weakness."
Arthur frowned. "My weakness."
"You possess raw power that rivals the gods. You have gathered knowledge that would take lesser men ten lifetimes to read. But you do not truly know how to utilize it to its absolute best." Odin stopped directly in front of him. "I have watched your battle with Laufey. I have watched all the training battles with my son. Your fighting style is completely flawless. It is perfectly planned. When you have all the information about your opponent, you are unbeatable. You have plans and contingencies for absolutely everything your opponent can throw at you."
Odin stepped closer, his presence suddenly overwhelming.
"But where truly seasoned fighters excel is the ability to tackle the absolute unknown. You fight like a grandmaster playing a game of chess. But what happens to the grandmaster when the opponent simply flips the heavy wooden board and sets the table on fire?"
Arthur was not as shaken as Odin expected. He had known about the gap for a very long time.
For all the times he had sparred the Ancient One, Carol, Thor, the Asgardian warriors, none of it had truly challenged him. Not in the way that mattered. He won those fights with preparation and foreknowledge, not instinct. The only opponent who had ever forced him to improvise without a net was Mephisto, and even Mephisto had come in stages. It took two encounters before he understood the demon well enough to win the third. Every other battle had been a calculated execution.
He lacked true, blinding battle experience. The kind of experience that only came from fighting in the dark against things he did not understand.
"Your nights in the archives mean there is very little left in the cosmos that can surprise you," Odin continued. "But there are always unknowns, Arthur. Always. And there is no quick road to the experience that meets them. You can do nothing but fight. More people. Different people. In situations you cannot control."
Arthur nodded. But he was not worried. His foreknowledge would keep the gap from ever growing into a real problem. But he accepted the critique.
"You're not wrong," Arthur admitted. "But there are only so many beings in this universe who can truly push me. The genuinely unknown ones, the ones I cannot read clearly first... you can count them on one hand. I would have liked to spar with you, the All-Father, to gain that specific experience." A dry turn at the corner of his mouth. "But I do not think that is possible."
Odin went very still.
"So you can see it," the King said.
"Yes. You have years left. Perhaps a decade, if you're careful. But a true, sull power fight, against something that could actually push you, wouldn't cost you years." Arthur held his gaze. "It would cost you the whole decade in an afternoon."
"It would." There was no shame in it. Only fact. "And I do not have the luxury of being careful, nor of spending what little I have left on a friendly bout, however much I would have liked to learn what a mortal has become." The eye held him. "Every fight remaining in me, I must keep in reserve. My successor is not ready for what comes when I am gone. Thor is a finer man than I ever was, but he is not yet a king, and realms have died in the gap between those two things. I cannot hand him a fragile kingdom and a cosmic catastrophe in the same breath."
"Hela." Arthur said.
"Yes." Odin was not surprised. Frigga had told him what they discussed. "Hela. My firstborn. My proudest child."
He looked at the empty pedestal.
"She was born with an innate connection to death itself. She could feel the ending of things before they came. A wiser man would have helped her carry that burden. A better father would have taught her the worth of the life she was so capable of ending." Odin's jaw tightened. "I did neither. I handed a child a sword and praised her every time she brought me a fresh crown soaked in blood."
Arthur listened in silence. There were no excuses in the old king's voice.
"There was nothing in my mind then but conquest. I did not see the damage it did to my daughter until it was done. By then she was lost to me. Consumed by the very thing I had weaponized." His hand rose toward the empty pedestal and did not touch it. "So I did what I have always done with my failures. I sealed it in the dark. I struck her name from every record and forced a kingdom to forget her. I locked my own daughter in a box and called it mercy." The hand fell. "And the box is fraying now. When it gives, she returns exactly as I left her. Unhealed. Unreached. A wound I made, walking and armed."
"You want me to stand with Thor when she returns," Arthur said.
"She was my ultimate pride. Without your help, Thor will not win the fight." Odin stood tall, the weary old man instantly replaced by the commanding king. "I am in no position to demand anything of you, Arthur Hayes. But I cannot pretend Asgard will not need your strength. So I ask you as a king. What do you want in return?"
"Nothing," Arthur said. "Asgard has given me what I needed. And I already promised Frigga I'd help."
Odin looked at him for a long moment, and something in the old face loosened.
"Of course you did." A breath that was almost a laugh. "She asks the important things long before anyone else knows to ask them. I gave up being surprised by it an age ago." He inclined his head, slow and deliberate, and it was not the nod a king gives a subject. It was the nod one old soldier gives another across a field they have both bled on. "Then you have my thanks, Hayes. Not the king's. Mine. For a kindness to a wayward son who did not earn it, and a burden you have taken up that was never yours to carry."
"It's becoming a habit," Arthur said. "Carrying things that aren't mine."
"I know the habit well." The old eye glinted, dry. "It is the most expensive one a man can keep. And the only one worth keeping."
There was nothing left that had to be said. And having said the heavy things, neither of them rushed back toward the light.
Odin lowered himself onto a low stone plinth, Gungnir across his knees, and gestured Arthur toward the bare pedestal across from him. For a while they simply talked. Not as king and guest. As two beings who had each seen more than most things alive, comparing notes on a universe that had spent a great deal of effort trying to kill them both.
Odin spoke of wars older than the histories remembered, of realms that had risen and worn smooth so long ago their names were lost. Arthur spoke of Earth, of the stubborn, breakable species he had thrown his life behind, of the completely ordinary life he liked best. They argued, without heat, about whether a long life was a gift or a sentence. Odin held that it was both, and that the trick was forgetting which on any given morning. Arthur said he didn't know yet. Odin told him he definitely would, in time, and that he truly hoped Arthur met the knowing of it much better than he had.
They talked of children, and of wives who saw straight through a man, and both went quiet for a while after that.
It was, Arthur would think later, one of the better conversations of his life. He had come down the cold stair braced for a warning, a burden, and a dying king's regrets. He had been given all three. He had not expected to also be given this. An hour in the dark with someone who had nothing left to prove and nothing left to hide.
He was almost sorry when it naturally ended.
But threads do not stop fraying for the sake of good company. As the hour wore on, Arthur watched the old fire dim with it, the talk quietly costing Odin more than he let into his voice. When a natural silence came, Odin rose, leaning on Gungnir as a staff now rather than holding it as a spear, and the full weight of his years settled back onto him all at once.
It was time to go.
He walked Arthur to the foot of the stair, and there he stopped, and set a heavy, weathered hand on his shoulder. It was the first time the King of Asgard had ever touched him.
"You are a good man, Arthur Hayes." Odin looked deeply into his eyes. "You have built a fortress of people who care for you." The hand was firm and certain. "My true failure was not Hela, and it was not Loki. My greatest failure was that I sat alone on a high golden throne and simply stopped listening to the people around me."
He gave the shoulder a firm squeeze.
"Never stop listening to the people who love you enough to look you right in the eye and tell you that you are wrong. I was terribly wrong in many things. I was wrong in how I handled my bloody conquests. I was wrong with my daughter. I was wrong with my sons."
Odin dropped his hand and took a slow step back, into the shadows at the edge of the Vault. He offered a final, weary smile.
"Do not live with ghosts and regrets like I do. Go home to your family."
Arthur bowed. Not deeply. But he meant every degree of it.
Then he turned and climbed the long stair toward the light, and behind him the old king stood alone among the weapons of his finished wars, a grey shape in a grey robe, growing smaller in the dark.
—
He found Frigga in her garden on the way out, and sat with her a while among the flowers that grew nowhere else in creation. He did not speak of what her husband had said. Some things needed to settle in the dark before they could be carried into the light, and she did not ask.
That night, when the portal had closed and his own home folded its warmth back around him, Eileen looked up from the couch and asked how Asgard had been.
Arthur sat down beside her and told her everything.
The grey at the edge of an old king's fire. A daughter sealed in the dark and a kingdom made to forget her. A weakness Odin had found in him that no enemy ever had. A dying ruler in a plain grey robe, who had conquered nine realms and learned, far too late, that his one unforgivable failure was that he had stopped listening to the people who loved him.
Arthur told her absolutely everything. Because Odin had told him not to stop listening, and Arthur knew that listening always started with talking.
Eileen listened intently to every single word. She did not interrupt once.
And Arthur was beginning to truly understand that it started right here. On this comfortable couch, with his wife. Refusing, for once in his life, to carry all the heavy things alone.