Title: I do solemnly swear
Rating: PG
Summary: In which our heroes learn the perils of lack of inter-team communication, and Loki has his day in court.

Author's Notes: For a while I hesitated publishing this story, because I feel it's not really one of my best. It's not all that original or interesting - people have done this idea before - and in some parts it's more of a meta-argument in fic format than a proper story. But, I wrote it, so make of it what you will.

Set post-Avengers.

When he next returned to Midgard after the battle of New York, Thor's heart was heavier than it had been in many a year. Even on his last descent, though half-wild with anxiety and his heart heavy with dread at all Loki had wrought upon this world, he had not felt anything like the same despair. For then there was still the promise of action to stir his blood; then there was still the possibility, however distant, that Loki might reconcile with him and come back to Asgard in peace. Then, there had been hope.

Now, there was not even that.

He still loved his brother. He didn't think that will ever stop, not unless the beating of his heart were to stop along with it. But love was no longer enough. All Loki did at home - bringing the Jotun into Asgard, assaulting Heimdall, sending the Destroyer, raining death down upon Jotunheim - it could be argued. It could be waived. It could, perhaps, be forgiven.

But there was no forgiveness for what Loki had done in his madness, in his cruel game that was no longer a game. People had died. People died in in the laboratory and they died in Germany and they died on the Helicarrier while Thor watched and could do nothing -and they died in New York, too, even whilst they labored to bring down Loki's strange, hideous army from the sky. They were only mortals, perhaps, but they were people all the same and their deaths could not be overlooked.

So it went. Loki had returned to Asgard to stand trial. Midgard was under the protection of the Allfather and his crimes would be weighed and retribution distributed appropriately. Thor loved his brother, but he knew with a heavy heart that there was nothing he could say or do to shield Loki from the consequences of his actions. The justice of his people was harsh - it had to be, to hold sway over a people so proud, so strong and so resistant to censure, who lived so long and could carry grudges for eons of time. Thor did not know what the punishment was to be, but he knew it would not be light.

Loki would survive it, of that Thor was certain. He had the resilience of his people - both his peoples - and his body was not weak. But Thor feared for what would become of Loki's mind afterwards. He was already so twisted, so warped by rage and pain. It could not possibly do aught but ill to force yet more pain upon him.

Thor knew not what else to do. He could see no way past this tangle.

So when Odin took command again, Thor had no thoughts but to do his bidding. Mother always said that there was a reason for everything his father did, no matter how arbitrary nor cruel it seemed at the time. And now Odin had ordered him back to Midgard, there to collect the evidence needed for his brother's trial.

It was a logical assignment. Thor had witnessed the entire debacle from start to finish and already knew the gist of all that had befallen. He was known to the mortals, was deep in their conferences and already 'cleared' by their security. It would be easy for him to get the requested information, without going through the no-doubt tedious negotiations of an official envoy.

Nonetheless it was an assignment that gave him no joy. Thor's glory had always been in the battle, never the gruesome aftermath of the battlefield. Although they had won their battle against the Chitauri invaders - and it had been glorious, no one could deny that - the crumbled concrete shells and twisted metal girders left Thor feeling as defeated as he ever had after any rout.

There was a heavy weight in his step that had never been there before as he walked the streets of New York City. Mere days had passed on Asgard since the princes had returned - one triumphant, one disgraced - but over a month had elapsed in the mortal realm. Much of the debris had already been cleared, and in some places skeletal new repairs showed above the ravaged skyline. Truly the mortals were a resilient people, recovering quickly from shock and lending their industry towards rebuilding what had been lost.

But that could not diminish the impact and tragedy of what had transpired to bring this great city to such a pass. The folded parchment - SHIELD had not been able to make use of any of Mimir's memory crystals, nor he of their flashing drives, so they had compromised on this printing - lay on his breast like a lead weight. Frozen images, transcripts of the video footage of Loki's first emergence into Midgard. A detailed timeline of the events of the days that followed. Estimated monetary damages, ranging in the billions. Estimated death tolls - even now, weeks later, they had not found all the bodies, and likely never would.

Brother, how could you do such a thing? Thor thought, furious and grieving. However hurt and angry you may have been, these people never did a thing to harm you! Why did you not bring your army against Asgard, as would have been an honorable and proper path to your vendetta? That Loki had directed his thwarted rage against the weaker, undefended target smacked of cowardice, and Thor hated to think of his own brother as a coward. Yet the evidence he bore said otherwise.

Now that he had that evidence, Thor knew he should return to Asgard. Loki's trial was already underway, had been all that terribly long day, and would continue for interminable time yet. But here on Midgard where the stream of time flowed more swiftly, Thor knew that he could steal a precious few hours for his own solace, and still not be late upon his return.

His steps turned towards Stark Tower.

Here, though at the center of the devastation, the repairs had been most swift. Already power was restored to the tower, humming and glowing in the desolation around. Shattered glass and concrete had been swept from the pavement, the broken walls and windows repaired. Though many of the streets surrounding it were blocked to their metal ground-vehicles, others flitted to and fro the roof of the tower like ungainly birds. The only thing that had not been repaired, somewhat to his surprise, were the tall metal glyphs that spelled out his teammate's name in the local Midgardian script; all that remained was a solitary rune, defying the destruction.

Thor stepped into the lobby, and was challenged by the warden of this place, the disembodied voice that served the Man of Iron as a servant. The invisible squire greeted Thor politely and directed him to a sitting room some forty floors above ground level; Tony Stark, Steve Rogers, the Hawk and the Widow were all assembled there, although Doctor Banner had apparently departed some weeks before. An elevator arrived smoothly, waiting to convey him to his destination, but all Thor's earlier sojourns on Midgard had not reconciled him to the claustrophobic confines of these floor-lifts; he took the stairs instead. A mere forty flights was not enough to trouble him.

When he arrived at the appointed floor, a greeting for his shield-comrades ready on his lips despite his depression, he never got the chance to voice it; Tony pounced on him almost as soon as he'd entered the room, the blue glow of his chest-borne phylactery giving his expression a febrile cast. "So what's he planning?" Tony demanded.

He stalked forward until Thor was backed almost against the wall, a ridiculous sight they no doubt made with how much he outweighed the other man. "Have you figured it out? If you have, please share it with the class, I'm going nuts here. Has he spilled the beans yet? Have you pulled out the thumbscrews? I'm betting you've got really epic thumbscrews up in Asgard, they probably aren't even thumbscrews, you probably have something that's way better, spinning rims and chrome and all. But the point is what is he planning?"

"And a good day to you, my comrade, as well," Thor got out, feeling a bit bewildered. "It is meet to find you in such good health and, uh, spirits." He looked around the room at the other three, a hint of pleading in his expression.

"He's been like this all week," Natasha said in a long-suffering voice. "Don't look over here for help, at least he's not bothering one of us for a change."

"He's planning something," Tony shot back over his shoulder. "He's got to be, I just know it. It's driving me crazy. You must know something, right?"

"Tony, leave off him," Steve intervened, blessedly diverting Tony's attention from Thor long enough for him to cross into the room and lower himself creakingly onto a wide metal-and-leather divan. Similar seats were scattered around the room in a foursquare pattern, with the two dark agents sharing one, Steve sitting on a third, and Tony prowling the room like an agitated beast of prey.

"Thor, it's good to see you again," Steve said, turning all his earnestness on the thunder god. "But, we really would like to hear what's going on in Asgard. There hasn't been much news since you left with the Tesseract and - well." He broke off, his fair skin reddening slightly as he averted his eyes, no doubt uncomfortable at the idea of asking Thor point-blank about his traitorous brother.

"With the Tesseract and your axe-crazy wannabe-conquistador of a brother," Tony filled in helpfully, and Steve and Thor both winced. "Who went way too quietly, if you ask me -"

"Nobody did," Clint muttered under his breath, but Tony ignored him.

"You do still have him, right?" Tony demanded. "Oh my God, you didn't come down here to tell us he escaped, did you? Tell me you didn't let him escape. That's just the sort of thing he would do, wait till he was out of reach of the Avengers and then give you the slip. Did he steal anything from Asgard? I bet that's his plan. This whole Independance Day re-enactment was just a smokescreen, Act 1 of his incredible Xanatos gambit. Get you to take him back to Asgard, then do a runner and steal something, I bet you have all the best weapons, he could grab something out of your vaults that would make that scepter of his look like a playskool toy - "

"Peace, friend Tony," Thor finally got out, raising his hands as if to ward off the spate of words. "I can assure you, we still have... Loki in the custody of Asgard. Our bonds are not easy to slip, even for a sorcerer such as he." He brooded on this for a short time, remembering his brother's familiar shape, bent by chains and tight-clasped by the metal restraints that kept him secured. "His trial continues apace."

"That's still going on?" Natasha's lovely eyebrows rose in disbelief. "It's been over a month. I'd have thought they'd reach a verdict by now."

"The proceedings continue with all possible haste," Thor assured her; indeed, the scramble to summon all the appropriate members of the Thing from the corners of Asgard had been somewhat unseemly. All had been made ready and begun within days of Loki's return to Asgard, and that was haste indeed.

"But since he is - was - is still a Prince of Asgard, never having been officially disowned, there are any number of formalities that must be waded through first." He sighed. Not all of those who had arrived for the trial had been summoned; there were plenty among them who had come just to gawk, or to gloat. Loki had made many enemies in his youth, and even of those who were not, the spectacle of a son of Odin being brought to such humiliation and disgrace was the show of a thousand years and not to be missed. Yet whatever their reasons for coming, be it a sense of justice or merely enjoyment of a show, tradition decreed that a place must be found for all of them. "I was sent to gather word of my brother's doings in Midgard, for use in that part of the trial. Upon my return the last of the witnesses will be called, and the Thing will announce its verdict."

"I understand," Steve murmured, and his expression was that of stern sorrow. Natasha's was more guarded, and Clint looked openly vengeful. Thor supposed he could not begrudge him that, for all of them save Eric Selvig, Clint had endured the most ill-use at his brother's hands.

Tony, on the other hand, would not be sated. "Look," he said. "I've been thinking over this ever since you left, Thormeister, and it just doesn't add up. After we cancelled his little war, Loki went waytoo easily. Even with the sweet-talking the Hulk gave him, he had plenty of time to escape from Stark Tower before we got back to him. He could have run off, or teleported, or just sat there and made himself invisible, or set up an elaborate and yet karmically appropriate trap to blast us all to Milwaukee as soon as we set foot on the terrace. You know him better than any of us, Thor, am I right or am I not?"

"You do have the right of him," Thor admitted, somewhat uneasily. Truthfully, it bothered him more than a little that Tony Stark's insight into his brother exceeded his own, who had known him for hundreds of years and yet never, apparently, understood him for a day of it. "My brother has always been skilled at illusions, and he knows the secret pathways of Yggdrasil, that allow him to walk in the shadows between worlds without the aid of the Bifrost. It was something of a mystery to me as well, why he chose not to do so."

"So did you ask him?" Tony said impatiently. "I mean, come on, kind of a pressing question here!"

"Uh, kinda hard for Loki to say much of anything with that gag on him," Clint pointed out dryly. "That was kind of the point of the thing, to shut him up for a change."

"It was a necessary precaution, to stop him from speaking words of seidh, yet by the same token it prevented me from questioning him as I would have liked," Thor said quietly. "Yet I did ask him, once before I bound him; why he had changed his attitude so, why he had at the last ceased fighting and surrendered. I did not understand the answer he gave, however, and there was no time for more."

"What'd he say, what'd he say?" Tony demanded, and the full-grown man was practically bouncing with impatience, jittering from foot to foot.

"Sorry about this," Natasha apologized, "you would not believe how much caffeine he's had today."

"He said -" Thor thought back on that dark afternoon, frowning. It was difficult to bring the words to mind, for they had made no sense to him at the time and it was hard to retain things that seemed like nonsense. But there had been only two words, and the whole of the scene had burned itself unforgettably into his memory. "He said, 'cranial recalibration.' I think."

After a moment Thor glanced up, to find the Avengers stock-still in their positions, as though he had uttered some magical incantation to turn them to stone. "Are you sure?" Natasha asked in a strange, flat voice.

"Verily," Thor said, bewildered and beginning to get angry with it. For all he had learned patience over the past year, his temper still slept within him, and anger was always the first emotion to come to hand when he was uncertain of himself or the situation. "That was what he said. Why? What does it mean?"

"It means we fucked up," Clint grated. "Big time."

~to be continued...