So. Uh. Yeah. This is more or less the longest thing I've ever written. It's also the first fanfic I've written in years o.O

There will be frostiron, and small amounts of angst. Because we all have Loki feels :3

None of the characters are mine, etc. Enjoy. Comments/criticism much appreciated.

"So, what are we going to do with him?"

The Avengers were sitting around the table of one of Stark Tower's many kitchens. The reason Stark Tower had so many kitchens was really quite simple - for Tony Stark, "kitchen" was essentially a synonym for "large liquor cabinet", and Tony Stark was not a man who liked to be more than five floors away from a liquor cabinet. Therefore, Stark Tower - by then Avengers HQ - had a large number of kitchens, almost all of which were almost always well-stocked (although not always with food, per se), and it was around a kitchen table that the Avengers had gathered to discuss the fate of their newest…guest.

"I want him out of here," Fury said, gesturing to the hologram hovering just above the table. "Lock him up, send him into space, hell, send him to another dimension, just send him away from here."

"My brother will cause mischief wherever he goes," Thor said, his expression stony. "Simply sending him away will not put a stop to it."

The hologram of Loki - the image taken directly from the cameras in his cell - smirked, almost as if it could hear them.

Capturing Loki had been easier than Tony had expected, in the end. In the past, capturing their friendly neighbourhood chaos god had never gone well. Well, to say it hadn't gone well was an understatement, really, considering that the last time they'd "captured" Loki, he had managed to take over a small city from the inside of his cell, and that his escape had involved flooding and major property damage and frankly sickening amounts of shape shifting and transfiguration, and they still hadn't figured out how to remove the tentacles safely, so a few guards were still-

Anyway. It hadn't gone well.

But this time, Loki had seemed - almost off his game. Sure, there had been a few craters, but eventually it had only taken four of them (Widow, Hawkeye, Iron Man and the ever-sparklin' Captain - two ex-assassins, a tin can full of sarcasm and the personification of patriotism, and oh boy, weren't they a team) to take him down. Thinking about it, Tony almost felt as if he'd cheated. None of them had come away with anything that would take more than a week to heal, and Loki had given himself up with a smirk. They'd brought him back to the Tower in silence, put him in the sturdiest cell they could find, and voila. One captured chaos god.

"I don't like it," Clint said. "Loki's as tough as hell, he's never this easy to bring in."

Tony eyed the hologram suspiciously, thinking. On some level, he knew Clint was right. Loki was tougher than this, and the way he was smirking at them from the corner of his cell was…more than worrying, and really, what was to say he wouldn't just break out and kill them all in the middle of the night?

"Well, what are we going to do, let him go?" he said. "I mean, seriously, the guy's probably planning something, but we can't exactly just turn him out onto the streets. Not that there are, uh, any streets left around fifty-second street right about now, he kinda made sure of that…"

"We're not gonna let him go," Fury cut him off. "But I'm not happy about keeping him here, either."

"Well, have we tried talking to him?" There's something inherently polite about the way Steve talks, as if his voice carries with it an echo of the 1940s. "No, I know we've tried - alright, repeatedly - but do you think we might be able to get him to see reason?"

Thor perked up at that; Fury simply looked sceptical.

In his cell, Loki was letting tendrils of green light curl around his wrists and over his fingers and Tony couldn't help but think - because this is how his mind works, how his mind has always worked, he has never been able to resist taking things apart to see how they work, to see how they could be changed, adapted for other uses -

"Guys," he said. One by one, the others turned to stare at him, and he knew he must have had the most whacked-out look on his face, but his thoughts were racing, because damn, you couldn't find a more perfect test subject if you tried, well, without the homicidal urges, but-


"We could use him," he said, bringing his attention back to the present with a jolt. Fury simply raised his eyebrows, and the expression on Thor's face said that he had to tread very, very carefully here, so he continued slowly - "Loki's key advantage is his magic, and we've never had much opportunity to study that in-depth - no offense, but there's only so much we can do with Mjölnir when no-one can lift it - and if I could just figure out how it works, I'd be willing to bet that we could use it-"

Fury still looked sceptical, but Banner was looking up, a gleam of interest in his eyes.

"Tony's right. I mean, Loki might not be the most willing participant, but this is a huge opportunity…"

"I will not have my brother harmed," Thor said, in the kind of voice that brooks no opposition.

"The kind of scans I'm thinking of, I wouldn't even have to touch him. Not that I'd really want to."

"I don't see the problem with that. If you can convince him to let you anywhere near him." This from Natasha, who was lounging against a counter with an expression that simply screamed bored.

Fury remained silent for a moment longer, but eventually he nodded, and Tony felt something glorious and manic blossom in his chest.

"Alright. But if I hear you've opened up a portal or turned the rest of the team into rabbits or whatever, I'll have you doing paperwork for the rest of your goddamn life."

In the past, Tony had tried to figure out what Loki's magic was. Of course he had - he's a genius, he's spent his whole life picking things apart to see how they work. And really, after taking a few blasts of unidentified green lightning to the chest, the drive to figure it out became impossible to resist.

And he'd made progress. He'd tracked radiation and measured energy fluctuations, designed whole systems to measure Loki's magic and its effects. He'd built things - cameras and scanners and shields, all specifically designed to track and trace whatever it is that Loki does. (Half of these machines had, incidentally, been lost; Tony Stark is not a man who is careful with his possessions, and his workshop…well, the less said about his workshop, the better.)

But the thing is, it's difficult to research something you don't have access to. Mjölnir might be magical, but it also apparently weighs about as much as a dwarf star, which makes it impractical for research purposes, and it hardly compares to a real, living subject.

So, yeah, Tony was excited. Because whilst being a superhero is fun, he is a scientist at heart, and this is what he lives for. He dreams of dissecting the universe, teasing out its secrets, and hell, Loki might be a chaos god, he might be a maniac and a murderer, but he's also a walking cipher, a fucking torrent of discoveries waiting to be made and this? Yeah, this is what Tony lives for.

He bounded down to the cells (via his lab) with a grin on his face, looking for all the world like a six-year-old on Christmas morning.

Well, a six-year-old armed with a few miles of copper wiring, sixteen modified Geiger counters and a death wish. But hey, who was counting?

"Why, what a pleasant surprise."

Loki's tone was light, almost sincere. Tony found him lounging in the corner of his cell, staring up into one of the cameras, a bored expression on his face. He was still wearing his armour - and holy shit, these people really aren't familiar with the concept of comfort, are they - but the remains of their earlier fight, the dust and dents and scratches, had all disappeared. The bronze plates gleamed under the electric lights.

"Well, I aim to please," Tony shot back, because hey, he's a talker, always has been, always will be.

Loki grinned at him through the glass. It was an unnerving expression, bestial, all teeth, but Tony didn't care.

"Okay, so," he said, laying out his equipment - Geiger counters, radiation monitors, you name it, he's got it - on the floor. "Here's the deal." He let the words tumble out of his mouth carelessly, preferring to concentrate on the machines in his hands. "That magic of yours. It's, uh, it's quite something, really, and certain one-eyed directors would like to know a little more about it. So you're going to…sit there, or creep about and be sarcastic, or whatever you like to do to entertain yourself, and I'm going to sit here and figure out…how you do what you do."

"So, I'm a guinea pig."

Tony paused, looked up. Loki had moved closer, and was standing with the tips of his fingers pressed against the glass. For a moment, he wondered how Loki had managed to master colloquialisms like that, when Thor still spoke like a hero from a cheaply-made period drama.

"Yeah," he said, eventually. "Yeah, you're basically the mother of all lab-rats."

Loki quirked one eyebrow at his phrasing, but said nothing.

"And hey, you can talk about magic all you want, but I'm firmly of the opinion that your magic is just a different branch of science, and I am going to figure out how it works if it damn well kills me."

The smile that played about Loki's mouth was dangerous that time, and Tony suddenly wished he'd used a different phrase.

"Well then," Loki said softly. "You'd better get started."

And Christ, it was fascinating. Really. It took Tony two hours to find the right strain of data, the right kind of radiation, and then - well, he's a scientist, and even building his suit wasn't quite this fun, because he's fairly sure that the things he's discovering, the patterns he's tracing are entirely new, never seen before by anyone, and that's - that's brilliant.

For the most part, Loki seemed content to lounge in his corner, staring up into the cameras. Sometimes Tony would look up, only to find that he was being stared at by a pair of sharp green eyes, and he had to bite back his usual remarks (see anything you like?) because…well, he was sure that Fury was watching, somehow, and a part of him was still sure that Loki was only there for his own amusement. He was a god, after all.

But the hours rolled by, and nothing happened. Pepper came to check on them, and then Steve; both seemed surprised to find Tony alive and well, and still in possession of all his internal organs. The guards changed and changed again, and still Loki sat and stared, idly allowing wisps of light to weave between his fingers, saying nothing.

Of course, it couldn't last.

It had been almost five hours, and Tony was just beginning to test a freshly-built spectrometer - …damn, if I could just figure out what kind of spectrum I'm dealing with I could…- when he looked up to see Loki's reflection grinning at him from a screen, eyes glinting. Tony spun round with a curse, breath coming short, reaching for something -anything - to use as a weapon (as if it would do any good) - only to find himself facing an empty room. Loki was still sitting in his cell, wearing an expression of perfect innocence.

Tony dropped his hands to his sides with a muttered expletive, shot Loki a look that said fuck you, and went back to the monitor.

"So," he said - anything to break the silence. "Why are you here?"

Loki stretched, cat-like, tipping his head back to reveal a shockingly white throat.

"I think you might do better to ask your comrades that," he said. "I am your prisoner, am I not?"

Tony turned to him. "No, don't give me that. You could break out of here in five minutes flat if you wanted to, we both know it, but you're just…sitting there. Why?"

"Trying to give me ideas?"

"Just curious."

Loki simply smirked.

"Maybe," he said delicately "I am plotting to kill you all in your sleep. Maybe I am gathering information. Maybe I am simply bored."

Tony met his gaze for a moment, before turning abruptly away. "And maybe you just wanna freak Fury out." Loki snickered at that. Tony went on. "Either way, looks like we're working together, and, hey, workmates should know the worst about each other, right? You oughta know, I'm very disorganised, never clean up after myself, periodically set the place on fire, you know, minor faults, my charm makes up for it. And to be fair, you're a megalomaniac with daddy issues and you threw me out of a window, so I'd say it balances out, right?"

Loki opened his mouth to reply, but at that moment JARVIS interrupted.

"Director Fury has an urgent message for you, sir."

They were being watched, then.

"Go ahead."

"He says that if you continue to fraternise with the prisoner, he will use your intestines to asphyxiate you. Sir." JARVIS said pleasantly.

Tony pulled a face, and went back to work.

I'm planning to update this every two days or so, if you're interested. Thanks for reading ^^