Secrets had been a part of Tony's life from the very start. From the day he was born, a tiny hatchling curled against the scales of his mother's chest, secrets had been whispered into his ear. Never show them who you are, was the first thing he ever learned. Never let them see. Even before he knew how to do more than draw breath, he was taught the magic to make him hide, to keep his real heritage protected away from the rest of the world.

He was the only dragon to be born of Midgard – Earth – that he knew of. There were no others out there like them. His mother, a beautiful Light dragon, made sure he knew all the stories about his kind and their lives on the other realms. She told him the history of the Light dragons found of Alfheim, and of the Fire dragons of Svartalfheim, where his father came from.

Tony soaked it all in like a sponge. He absorbed every bit of their history, every magic lesson his mother taught him.

But nothing had sunk in as deep as those earliest words. Those, Tony carried in his heart. Never show them who you are. Never let them see.

It was a motto that Tony Stark shaped his life around.

He hid from everyone right underneath their noses. They wanted to see a human? He gave them a human, putting himself in the spotlight, living up to every single expectation they had of him, all the while knowing that if the world honestly knew him, they'd come to despise him far more than they did already.

Tony made it through life without ever once revealing his secret. Not even in the dark caves of Afghanistan did his secret break free of the magic he hid it under.

It stayed hidden right up until the day an insane Norse god came to his planet to try and take it over.

After that, there was no going back.

Tony knew of Loki Odinson long before Coulson brought him the files. He'd first heard that name when he was still a hatchling climbing along his mother's back and begging for stories. The second son of Odin was both a mystery and a pleasure to the dragons, it would see. A creature that was just as strange as Tony often felt he was. Born of ice, yet a god of fire, he was opposing forces trapped inside of one body. Two different parts of him, two different worlds he belonged to, and yet he walked them all.

When Tony saw the file on him, every instinct inside of him was demanding he go and find him, that he protect the one his mother said the dragons had claimed as Dragon-Kin long ago.

Finding him proved to be a whole lot easier than anticipated. Facial recognition placed him at a party in Stuttgart, Germany, and he wasn't exactly hiding when he went there. It didn't make sense to Tony, and he earmarked it as something to think about later. Of course, a lot of it quickly started to go into the whole 'not making sense' pile. Like how fast he was able to knock Loki back, how he just gave in instead of teleporting away when Tony threatened him with a repulsor blast, and later on, how he didn't try and run when Thor and Tony were fighting. He actually waited for them.

All of it was a puzzle that Tony needed to figure out. It was very, very important that he did. If the old stories weren't enough to convince him of that, opening his helmet and getting his first scent of the god was.

It'd taken everything Tony had not to stumble right over to Loki and curl up around him. His scent was smoke and fire, fresh snow and heavy ice, and home. But there was something else to it, something that, as Tony moved just slightly closer, took all those pleasant scents and edged them in a foul sense of wrongness. Like a thin layer of slime overtop of it all.

Then Thor arrived, and there was no more time to think about it. No more time for Tony to analyze anything beyond his fury at the audacity of anyone taking what was his. Tony had his helmet on and was off the jet in an instant, not giving a damn about the protesting soldier shouting behind him.

They all ended up on SHIELD's Helicarrier. Being here never failed to give Tony the chills. Though he was sure SHIELD had no idea about them – he had JARVIS monitoring them continuously, so deep in their systems they'd never be able to pull them out if they were ever even lucky enough to find him – he couldn't help the fear that they might learn something. That he might slip somehow and give himself away. If that happened, any life Tony had would be lost. They'd never stop trying to come for him.

Of course, getting the chance to meet Dr. Bruce Banner, working in a lab with him, made the risk worth it in Tony's head. He'd admired the man – and the beast inside – for quite a while, and he absolutely adored him from the instant he opened his mouth to speak. They shook hands and Tony got close enough to smell the strange, dual scents he possessed. Wet, heavy dirt, moss, fresh grass, and a faint hint of oranges that Tony had come to associate with any type of radiation. The gamma radiation that had made the Hulk seemed to produce a tangier orange scent that was pleasant.

If Tony brushed up against Bruce in the lab a little more often than he did with others, laying his own scent on him to mark this being as his, and if he made sure to feed him – because seriously, there was no food here, had anyone fed him at all? – well, no one else needed to know that, did they?

Tony didn't get the chance to face Loki again until they were both standing inside his penthouse. Here, where Tony's scent was the strongest, where a creature of magic like Loki should've been able to sense something even with all of Tony's careful wards up, the mage stood tall and proud and showed not a hint of recognition. There was something so wrong with that, Tony couldn't even find the words for it.

It should've been impossible, and yet…

Loki didn't recognize him.

The shock Tony felt at that was the only thing that kept him there as Loki brought his staff up between them. "How will your friends have time for me, when they are so busy fighting you?"

Tony's inner dragon was snarling as the magic stick touched against his arc reactor. Not that he was afraid it was going to do anything. The magic in the staff had nothing on the magic even a dragon as young as Tony carried. Dragons were magic in one of its purest forms. The little blue tendrils that reached out for him had no chance of ever making it to his mind. No, Tony's rage wasn't for that magic. It was for the being in front of him that he could see now was being held by the very same magic that was trying to ensnare Tony.

Loki looked utterly surprised by the lack of reaction. "This usually works."

"You can't have me," Tony's voice had dropped down to a low, rumbling growl, deeper than he'd ever let it show before. His body was aching to shift to his true form so he could find whoever had dared to take what was his and violate it this way. "And you can't have him."

In hindsight, he wasn't all that surprised at being sent flying through the window. The threat in Tony's voice had been clear, and Loki had responded. But Tony was done playing games.

There was no thought to it as he let his true form take over. Big wings snapped out on either side of him, and magic rippled down his body as it took on the shape it was meant to have. Tony opened his maw and let loose a battle roar as he caught the air current and spun himself towards the side, looping around and right back up to the window he'd just came through.

He hovered in front of it and enjoyed the shock on Loki's face as he took in Tony's form. He was a beautiful dragon and had no shame in spreading his wings wide so that Loki could see the full glory of him. The heritage of both his parents showed on his body. He had his mother's golden scales covering almost every inch of him, with the red from his father showing in the bones of his wings and the horns on his head, as well as the spikes down his back and tail and his claws. When the sun hit him just right, it seemed to shade the rest of his scales as wells, just a hint of it tinting the gold.

For one moment Tony let himself be seen for the first time ever by anyone else.

Then, with another roar, the dragon shot through the broken window and straight into the mage's body.

The two hit the far wall with a crash that almost sent it crumbling down. Tony grabbed Loki by the throat with his front foot and slammed him up against the wall. That slime was still on his scent, the little legs of blue power gripping him tight, and it only served to make Tony more furious. "You can't have him," he snarled right in the mage's face, his message for the one he knew was holding the leash. "He's MINE."

Tony's mouth opened wide, and he breathed out a wave of, not fire, but power, pouring the magic down Loki's body. It wrapped tightly around the god through the bond of blood and fire that they shared, one forged long, long before Tony was ever born. One that marked him as Dragon-Kin and made him theirs to protect, theirs to shelter, and theirs to avenge. Tony poured all the magic he had into Loki and shredded the hold of the one stupid enough to dare and touch what didn't belong to them.

Only when every last piece of it was clear from Loki did Tony finally let him go. He drew his magic back and very carefully set the little mage down on his feet.

It hadn't been comfortable, what Tony had done. Though his magic had been fueled by rage, it'd still been one hell of a battle. He was just a little shaky as he carefully sat down and braced his front legs on the ground. His wings drew in to rest against his body while his head lifted so that red/gold eyes could lock on the being standing in front of him, their heads almost level. Like this, Tony was just slightly larger than a horse, closer in size to a moose.

If Loki had seemed surprised before, he looked stunned now. Bright green eyes – no longer blue – were wide as they ran over him. "You saved me."

A huff had smoke curling out of Tony's nostrils. "Like I told your brother – no one touches my stuff."

Loki's eyebrows shot up briefly, and there was a brief flash of pleasure in his eyes. "I owe you a debt greater than I can repay, Winged One."

Snorting, Tony deliberately blew smoke at the mage this time. He swatted at Loki's shoulder with his right wing and chuckled as it made him stumble. "You don't owe me anything. I take care of what's mine."

"Yours," Loki repeated.

"Mine." There was power in that word that echoed in the room around them. No matter what else was going on, Tony knew with absolute certainty that this being in front of him was his. He had smelled it before, and he'd only confirmed it when his magic ran through him. Whether or not Loki ever wanted him in return, he was Tony's now, and that meant Tony would do whatever it took to watch out for him. This strange mage god of fire and ice, the Frost Giant who had bent fire to his will.

A slow smile stretched over Loki's lips. He drew himself up, body straightening to its full height for the first time since Tony had set him down. Gone was the fear that had been there moments before.

Any other time and Tony would've loved to stay there and enjoy it. However, there was something a whole lot more important that needed to be done right now, and with the staff lying nearby, there was no one else that was better suited to do it.

Tony brushed off any exhaustion and forced himself back up to his feet. He had a realm to save and some aliens to destroy. Then, then, Tony would take his time admiring the newest member of his clan and making sure that Loki was okay, drawing him in close and sheltering him with his body until Loki could rest and eat and be well once more. For now, he had to leave him here, in the safety of Tony's lair. With that in mind, Tony pushed himself forward, using his head to butt against Loki's chest and nudge him back towards the couch. He'd caught him by surprise enough that he managed to knock him down onto it before Loki thought to protest. "You wait here," Tony told him firmly. "I'll go handle the infestation."

It probably shouldn't have been as cute as it was to see the indignation rise on Loki's face. "I absolutely will not!"

He tried to push up, only for Tony to duck down and knock him back down again. "Yes, you will, Lord of Fire and Ice. I need the staff to shut down the portal, and I'm not looking to rip it away from your head again tonight."

"So carry it yourself," Loki insisted, looking not the least bit displeased to not have to go near the staff again. "I will watch your back while you close the portal, as Kin should do."

The idea held merit. More than Loki probably realized. Because not only would the Chitauri try and stop him, there was a good chance the other Avengers would as well. There was a slim chance that Tony's transformation had been missed. With the mage at his back, keeping him safe, it would make Tony's job much more manageable.

This time he didn't stop Loki from getting to his feet. He just watched as Loki stepped up towards him and raised a hand to press against the side of his face. "You are a beautiful and magnificent creature. Truly glorious. I don't doubt your strength, my fierce one. I simply wish to be at your side as we right the mistakes that I have made. These creatures, they have wronged me, helping my jailer to contain me so that I committed terrible crimes. Won't you allow me to stand at your side and find the justice I deserve?"

There was no way that Tony could argue any of that. He rumbled, low and deep, and his tail flashed in agitation behind him. Then, ever so gently, Tony lowered his wings and squatted down. He turned his head to look at the surprised mage. "Climb on then, Silvertongue."

Loki was right. He had every right to demand blood-price be paid for the injustices done to him and the wrongs he'd been forced to commit. It was his right to be there, just as it was Tony's right to be at his side. They'd take these creatures on together.

He held still as Loki carefully climbed atop him and settled in at his shoulders between the spikes that ran over Tony's spine. It was the first time that Tony had felt the weight of anyone on him and he found that it was a surprisingly pleasant one. When Loki's knees pressed in and his hand settled against around a spike, Tony straightened himself back up and headed towards the spear, grabbing it with his front right foot. He walked them over to the window, staring out at the aliens below.

On his back, he felt it as Loki straightened himself up. Magic crackled around him. "Come then, Fire Lord. Let's go show the world what happens when you choose to fight with the wrong dragon."

The sound of Tony's roar echoed through the skies, twining together with Loki's laughter as they dove out the window.