Notes:

We were partially inspired by some of the theories proposed on the TV Tropes WMG page for the movie. We have taken the movie and combined it with the Eddas, the Gesta Danorum, and bits and pieces from other Marvel sources. We're having a lot of fun with it and hope you enjoy the result.

The room was blank white and sparsely furnished but, aside from the searing heat, not uncomfortable. Not at all what Loki would have expected to find inside a dormant volcano, even one he'd sensed the magic from while still a mile away. Normally no one came to this part of Asgard; he'd been looking to create a hideout from which he could reach the city without world-walking or he wouldn't have been there himself. Enchantments on a volcano had been unexpected, this rather ordinary room more so. But what made him stare in shock were the two on the bed. An ice giant and an Asgardian woman sitting beside one another and curled together like lovers.

The ice giant looked up and smiled, a welcoming look that seemed strange on that cold, blue face. 'You're a new one,' he said. 'Did Odin get tired of visiting me?'

A prisoner, then, thought Loki. That at least made sense. 'He did not send me,' he said, cautiously. 'May I ask who you are?'

'Loki Laufeyson,' said the giant. 'And this is Sigyn, my wife.'

Loki took a moment to gather himself, to suppress whatever startled reaction might have pushed its way forward. It seemed he had been recognised after all. 'You are not,' he said. 'You are mocking me.'

The giant only looked puzzled. 'In what way? If you have heard of me then you must see I am telling the truth. How many giants do you think Odin leaves in volcanoes?"

'I am Loki. And Laufey…is my father.' Loki was sure the effort it took to say that was visible.

The frost giant's eyes widened in surprise. 'Then I think it was Laufey who was mocking you, to name one of his runts after the last. Take a seat, little brother, and tell me how you came to be here.'

'Odin named me. I am more his son than Laufey's,' said Loki, the impulse to deny kinship with monsters overwhelming more sensible reticence.

The shock in those strange red eyes was the first strong reaction he'd got from the prisoner and Loki felt better for it, more in control. The Asgardian woman, Sigyn, put her hand on the giant's arm.

'Unlike him to be nostalgic,' said the giant. 'Perhaps you'd rather think of me as your uncle, then. Odin and I were sworn brothers.'

Oh. Loki had been told that he'd been named for an uncle, a great magician, as Thor had been named for an older brother who died in the last battle against the frost giants. It had been rather vaguely implied that the elder Loki had too. No one had mentioned he'd been named for a frost giant. It seemed it was Odin who had been mocking him.

Sigyn got up. 'Please sit down,' she said. 'I'll bring us all some wine.'

Loki nodded, grateful for the chance to collect his thoughts, and sat down at the small table. He quickly checked the magic around the place, he had known coming in that it was intended for only one target but there was a risk the coincidence of names might confuse it. There was no sense, though, that it was paying any particular attention to him and Loki turned his attention back to his namesake.

'You were fighting on the side of the Asgardians?' he asked.

The giant laughed, a surprisingly light sound. 'I wouldn't say fighting,' he said. 'And the whole thing was a little awkward from my point of view. I was glad enough to leave my father, but I still had friends in Jotunheim. Mostly I spent my time on Midgard, or ran less warlike errands.'

Loki forced himself not to drop his gaze, or show signs of how disturbing the thought of friends in Jotunheim was. Best not to mention what he had tried to do to Jotunheim if he wanted this conversation to continue. Sigyn returned with the wine, coming between Loki and the giant as she set his goblet on the table, and then returned to her place on the bed with her husband. It gave Loki time to focus on a different part of the conversation.

'Did they mind?' asked Loki. It wasn't the important question, but still… 'They mock me for fighting with magic. If you did not fight at all then I wonder what they said of that.'

'They didn't mind,' said the giant. 'They teased me endlessly, but that isn't the same thing as truly minding. And I found plenty to mock them with in turn.' He grinned, impishly. So strangely expressive for a frost giant. Or were more of them like this outside of battle?

'You talk of them as if they were friends. But they imprisoned you,' said Loki carefully. He was sure asking flat out 'what did you do?' wasn't a good approach, less sure of what would be.

The giant's look darkened. 'There was…a disagreement. It had nothing to do with frost giants and a great deal to do with plans for Midgard. Aside from neither of us wanting it turned into a glacier it seems Odin and I had different ideas about it.' He took a sip of his wine. 'How is Midgard now?' he asked suddenly.

'Full of self-destructive humans,' said Loki.

'Ah. They've always had a touch of that,' said the giant. He seemed almost reassured by the answer.

Loki blinked sweat out of his eyes, the heat in here really was almost unbearable. He considered bringing out the casket just to cool things down, but letting these two know he had a powerful magic artifact was probably a bad idea. He wasn't sure whether it could break the seal on this place, but he was sure they'd want to try it.

'You don't like Midgard?' asked the giant.

'It could be a great deal better organised,' said Loki. 'Too many rulers and companies grasping for their own interests. You like it?'

'I've never been keen on organised,' said the giant. 'They are, or used to be, a little too focused on dying gloriously. And certainly rather violent. But also chaotically creative. You have to love a race that decorates ear-picks.'

Loki wasn't sure what to make of reasoning like that. Possibly it meant he should keep quiet about his own plans for Midgard. He had, a little while ago, entertained the notion that the "disagreement" between this giant and Odin had involved the giant wanting to rule Midgard. Now he was positive that was not the case.

The giant sipped at his wine pensively and then said, 'If you are Odin's son you should be able to lift the enchantment on this place.'

Not his blood son, thought Loki. 'Why should I want to?' he said.

'For one thing I'm a powerful magician. I suspect I could teach you a great deal,' said the giant. 'And it would prove that you are Odin's son, would it not?'

'I don't need to prove myself to you,' said Loki.

'No. Not to me,' said the giant.

He understood. Loki had never been understood, not by the Asgardians, and being understood by this giant was more disturbing than gratifying. But there was still a pull to the idea, the desire to prove himself, with no idea how to do so, willing to jump at any notion. No matter how ridiculous it was to think Odin would see him as more of a son for letting out dangerous prisoners. Odin wouldn't approve. But Odin wouldn't approve of any of his plans. He was looking to be his Father's equal, not his favourite.

'Will you consent to be bound to obey me?' asked Loki impulsively.

The giant frowned. 'That would be a powerful spell.'

'I can do it.' He had the casket.

The giant's eyes flicked sideways to his wife. She met his gaze but didn't speak, and Loki couldn't read anything in her eyes beyond passive acceptance. She seemed a meek creature to be married to a frost giant.

'Say you will not use me in combat. I prefer not to be a weapon. And, in any case, I am hardly effective as one.'

'Agreed,' said Loki. A shame, since this giant was remembered for powerful magic. But he would teach it all to Loki anyway, given time.

'Then you may bind me.'

The giant stood and walked over to face Loki, who stood as well. They were almost exactly the same height. Loki held his hands out and the casket manifested in his grasp, the agonising heat dying down as it did. Loki's skin turned blue as he held it and he suppressed the flinch the sight of it caused.

'Odin did not give you that,' remarked the giant.

'It is my heritage,' said Loki. The casket responded to his will more easily than he expected. The bonds it created were invisible strands of ice cold air, showing only when they touched the giant and his skin turned a darker blue in strips.

'You are bound to my service,' said Loki. 'To teach, to act, to speak as I require. Only in battle do I exempt you. Be bound!'

The bonds seemed to dissolve and Loki thought they had broken, that the spell had been beyond his skill. But then they reappeared, like ink blooming through the blue skin, as lines of runes. The giant twitched his shoulders as if he was settling a burden and then nodded.

Loki took a breath. 'As son of Odin I release the bond on this place.'

The magic in the walls simply faded away, like the fading echo of a struck gong.

Sigyn lingered long enough for two things: to see the light and relief in her husband's eyes when he finally emerged from his prison and the caves into cooler mountain air, and to find out where this younger Loki would take them.

The latter proved to involve a particularly hair-raising trip between worlds. The boy didn't ask if they knew how and made fewer preparations than she'd ever seen, even when her own children had been young and reckless enough to fling themselves across the void and make friends or foes of the things that lived between worlds. As it was, they were towed rapidly through a veritable feeding frenzy - she wasn't sure what the creatures were after, but it was very much like swimming among sharks when you weren't the one bleeding into the water yet. The casket would have been useful, if he'd actually used it; perhaps its presence at least warned them off. He was tense and wary, but that seemed directed as much at her Loki as at any of the actual hazards of the journey.

She knew they were going to Midgard when she sensed Jormungand's drowsy stirring, and she relaxed somewhat when they were past him - he might not be paying much attention at the moment, but very few extradimensional predators were willing to violate his territory.

They emerged in a bland room, less spacious than the prison but significantly cooler. Sigyn marked the place in her mind, then gathered her own power and vanished with a light squeeze to her husband's hand, leaving him to explain her disappearance however he chose. Or, if necessary, however his namesake insisted.

The trip back, of course, was even worse. She emerged at the palace gates with sweat stinging a chemical burn on her neck from the blood of a metaphorical shark, and the energy of its death making her nerves itch and sing. She told the startled guards that she wanted to see the king. It had been a long time since she'd approached the palace. 'Sigyn Incantation-Fetter' seemed to mean little to them, when during the war with the Vanir it would have eliminated the need to ask Odin if he'd be willing to see her. She omitted 'wife of Loki' to avoid unneeded confusion.

Odin remembered her. She was conducted to a private room, not the throne room for audiences, and arrived at the same time as a young blond man in a great hurry who nevertheless let her enter before he went in to take his place beside Odin and Frigga.

'Odin,' Sigyn said, 'I think another of your children has gone crazy.'

'You've seen him?' the blond prince said, sounding more hopeful than alarmed. Frigga, likewise, straightened with her eyes suddenly bright.

'Thor,' Odin said - Sigyn looked at the blond prince again, and her stomach flipped and sank. She hadn't kept up with the news since Loki's imprisonment, but if this boy was Thor, she doubted she was going to see the one she'd known again. 'Let her finish.' His eye narrowed. 'I take it Loki has met his namesake.'

'Did you not feel your own spellwork end?' Sigyn smiled sardonically. Probably not, actually. At the same distance in space and time, she might not have felt her own spells defending the palace being modified either, which was part of why she hadn't gone straight in. (The other parts were courtesy - she did want him to listen - and a lack of enthusiasm for having to look for him.) But that was no reason not to needle him a little. 'Your heir released him from his imprisonment, as you allowed. His price was that Loki be bound to obey him. Using Jotunheim's casket.' She stopped and raised her eyebrows. 'As you may imagine, I have questions.'

'So do I,' said Thor. 'For one thing, I thought our, ah, Uncle Loki was dead.'

'I want to know what the young prince is likely to want from him,' Sigyn said. 'Or if you don't know that, at least what he's been doing.'

'We know less of that than we would like,' Odin admitted. 'It has been a month since he fell from the broken Bifrost, and this is the first we've heard.'

Sigyn stared at him. 'No wonder the space between worlds is such a mess. Start again, my king, a bit further back.' Her eyes narrowed. 'Perhaps when he learned he's Jotun. He didn't seem terribly comfortable with the idea.' Actually, he hadn't seemed terribly comfortable with anything, but her husband's lack of affection for Laufey didn't manifest in actually looking ill.

Frigga winced. Odin sighed. 'Not long ago. During a distinctly ill-judged,' here he frowned at Thor, 'investigative trip regarding a Jotun incursion into the vaults here. Shortly thereafter, he reigned while I slept, during which time he tried to kill Thor, lured Laufey here in person to try to assassinate me and killed him over my bed, and attempted to destroy Jotunheim using the Bifrost. Thor broke it; they both nearly fell from the edge, and Loki... let go.'

Sigyn shut her eyes for a few seconds and rubbed at the burn on her neck. She was right: the prince was crazy. Possibly quite a bit more so than Baldr had been. And now Loki, her Loki, had agreed to be bound to obey him. Well - that could be worse. He was very good at talking people around, at least when he kept calm about it himself. 'You made him king during impending hostilities with Jotunheim while he was still in shock about finding out he'd been born there?'

'That was my doing,' Frigga said. The pain in her voice was more obvious than that in Odin's. 'Odin had delayed the sleep longer than usual and then collapsed. We didn't know how long it would be.' Odin didn't precisely look embarrassed, but he did look displeased. He ordinarily slept only a single full day out of every year, courtesy of a long-past piece of magic that Sigyn personally thought had been a bit mad. At any rate, it didn't normally require a regent. She supposed it had probably been a bad time not to be sure who was in charge, but the boy she'd met still didn't seem ideal. 'Thor had been banished for his part in the trip to Jotunheim-'

'I am not sure I would have done better,' Thor muttered.

'-And Loki was also of age.' Frigga sighed. 'Holding the throne myself would have been a slight to him, and I meant to remind him that we did have confidence in him. I thought we could.' She raised a hand, palm up, and then let it fall. 'Odin took the casket from Jotunheim at the end of the war. They could have sent individual world-walkers against us, but not moved an army quickly.'

'I think the treaty with Vanaheim was better,' Sigyn said.

Odin eyed her. 'I cannot argue with that. And I thank you for... bringing warning.'

'Loki would want you to know, too.' The new binding was less restrictive than the old, which hadn't been subject to persuasion, but the boy clearly wasn't stable enough to be running around with that kind of power.

'Would he?' Odin asked.

Sigyn frowned at him. She'd hoped she hadn't really had to tell him. 'Even now, I thought you still had some faith in him.'

'Would someone please explain to me,' Thor broke in, 'exactly what we have been warned about? What can this other Loki do, that the one I know can now insist on? And Father, why had you imprisoned your brother?'

Odin looked grim. 'He gave Asgardian technology to a human king,' he said, 'to kill your brother Baldr and attempt to destroy Asgard itself.'

Sigyn's eyes widened, and she counted silently to nine, fingers flexing, before she could tell herself and believe it that throwing fire on the floor to punctuate her point would come across as a threat, not as emphasis, and that this was a bad thing at the moment. "Is that what you have thought all these years?" she asked, then forcibly unclenched her teeth.

Odin turned his head to her from Thor, and the rest of his body was very still. "It is what Hod did," he said. "And nothing that Loki said afterward suggested otherwise."

"He probably thought you had more sense than to believe he wanted Asgard to fall!" Sigyn shook her head. "He liked Hod. He - we wanted to put him on a more even footing with Baldr, seeing no reason he should be permitted to conquer Midgard easily just because he was your son." There was acid on her tongue as she added, "Evidently, you didn't agree."

Odin frowned. 'Baldr's excesses would have been... dealt with, had he survived, but he was hardly about to conquer all of Midgard.'

'I'm sure it would have taken him a while,' Sigyn said. 'So you didn't intend to help him with that?'

Odin gave her a wry look. 'Even now, I thought you still had some faith in me,' he said, his voice very dry. 'I saw no reason Baldr should not seek a high place among his mother's people, but I had no intention of conquering Midgard through him. We could not let him or Hod continue as they'd begun, but Baldr did not respond by proving himself more of a threat.'

'Let me see if I have this clear,' Thor said. 'Your husband has just been released from centuries of imprisonment over a misunderstanding, may think we intend to conquer Midgard, and is bound to cooperate with my brother in whatever he's currently trying to do.'

'He arranged an exception to avoid being asked to fight,' Sigyn said, 'and it has become apparent that Midgard is not conquered. That is where I left them. But otherwise, yes.'

'Ah,' Thor said, looking as if he might be developing a headache. Sigyn felt it was only fair for her not to be the only one. 'Lovely.' After a pause, his gaze sharpened, and he asked, 'Wait. You were able to reach Midgard? They're on Midgard?'

Sigyn gave him a puzzled look. 'At some hazard. The Bifrost's fall has attracted scavengers.' She touched the mark on her neck again. 'What kind of question is that? I suppose Odin can hardly go charging about world-walking under the circumstances - I wouldn't have gone myself if it were less urgent - but surely the art hasn't been forgotten.'

Thor shot his father a look. 'I was aware it had been known once,' he said, very slowly, then turned back to Sigyn. 'My exile was to Midgard.' His voice was strained. 'I... learned much, there, and made friends to whom I had promised to return.'

'I see,' said Sigyn. She did. Asgard had forgotten world-walking, mostly, except as an obsolete magic. Odin could hardly leave under the circumstances. Thor had thought the Bifrost's destruction would cut Asgard off from the other worlds entirely, rather than making journeys the domain of the very skilled and very bold. And he was holding himself back just shy of pleading. 'Well, I am not going anywhere right now. I need a meal, a bath, a bandage, and I could probably use something to set on fire. After that I can think about what to do when I return to them.'

'I will see to that,' Frigga murmured. Sigyn suspected she was not sorry for a reason to leave the room.

'Are you bound to obey my brother?' Thor asked suddenly, eyes narrowed. Not a bad question, if late in coming. More useful if he could compel her to answer truthfully.

'I am not.' Sigyn smiled thinly at him. 'He never asked me to agree to anything. I believe he thought I wasn't dangerous.'