A/N: If you were looking forward to the reactions of the Avengers…well, that's not happening yet. This is turning into more of a series of one-shots that probably won't have that much continuity. I place this one a little after Jack became a spirit.
It was the singing that attracted him. He was flying over Norway, heading towards Siberia, when the wind brought the deep, booming voice to his ears. It seemed to be a good song: all about victory in battle and beautiful women, so Jack dropped down to see who it was and listen to the rest of it. Walking along the snowy road were two men, one singing while the other had an exasperated look. The singer was a large, brawny man with golden hair and blue eyes. He wore armor that looked as though it had come from long ago and a red cape billowed from his shoulders. The other was the singer's opposite: black where there was gold, green where there was blue, pale where there was tan, and lean where there was brawn. Jack stood off to the side of the road, leaning on his staff and watching them. The blonde man was enthusiastic with his singing: flinging his arms and occasionally acting out the scenes told. The dark haired man, however, was looking steadily more and more annoyed at every near hit from his companion. Jack grinned at the two. He couldn't help it, they were just somewhat comical. When they were closer, only a few feet away, the blonde dropped his song.
"Greetings!" He boomed, looking straight at Jack. The winter sprite glanced around, confused. There wasn't anyone else around, so…
"C-can you see me?" He stammered, almost breathless. The dark one rolled his eyes.
"Of course. Do you think we are blind?" He snarked. Jack ignored him for the moment, a grin spreading across his face.
"You can see me!" He exclaimed, large white snowflakes beginning to fall in response to his rising excitement.
"Can others not?" The blonde asked. Jack shook his head.
"No. No matter what I do, no one can see me." He said, the sobering reality tempering his joy somewhat.
"Have you ever heard of this, brother?" The blonde asked. So they were brothers. That was odd: they looked and acted nothing alike. The darker one rubbed his chin, studying Jack.
"Very rarely… What is your name?" He asked abruptly.
"Jack Frost." He answered.
"I am Thor Odinson, and this is my brother, Loki." The blonde one, Thor, informed him. Jack frowned.
"I've heard those names before…" He mused, falling into his habit of talking to himself. He snapped his fingers and a flurry of snowflakes appeared to join their brethren.
"That's right! Those are like, Norse gods! Thor was the god of…thunder, and Loki was mischief and fire!" He exclaimed. He'd snuck into a house and heard a mother telling her son stories about the two. They seemed like fun to hang out with, even if Loki seemed to like fire. Fire and ice rarely got along, but Jack figured he'd make an exception in order to get the pranks. Thor held up a giant hammer Jack had somehow not noticed before.
"Indeed, the mortals think of us as gods because we live long and do not injure easily." He boomed. Jack grinned.
"Sounds fun!"
"Jokul Frosti!" Loki interrupted. Jack considered the name for an instant, then nodded.
"Yeah, that's my name. Kinda." He said. Loki rubbed his forehead.
"Foolish." He muttered, heaving a sigh, "you are a winter spirit, like Father Frost.* Thus, people cannot see you unless they believe in you. It's the price for your immortality and powers." He explained. Jack frowned.
"Powers that I never wanted. Great." He'd be more upset, but he had suspected as much.
"Anyways, where are you guys going?" He asked, shifting positions. He hated staying still this long.
"We seek adventure!" Thor answered, a wide grin splitting his face. Loki remained sulky, looking rather like a cat.
"Such as there is in Midgard." He muttered. Jack nodded and started float upwards.
"Good luck!" Just before he was out of earshot, he aimed a snowball at Loki's head.
"Lighten up, sourpuss!" He laughed at the glare the mischief god sent him. In the next instant he was gone, the wind whipping him towards his original destination.
Over the decades, he saw the two brothers a few more times. He and Loki began a prank war after the second meeting, generally through instigating rumors among the other spirits, some of whom Jack was beginning to meet. Altogether, he was beginning to feel less lonely.
When Loki attacked New York, Jack didn't hear about it until afterwards. He had been shocked. The trickster god had always been unbalanced, but never to that point. And he had never shown any desire to conquer the world, instead having only derision for it and the mortals living there. Jack had quickly made his way to New York, but the brothers were already gone.
A year later, when he felt the signs of Loki's magic, he immediately went to it. He found the Asgardian bitter and hateful, ordering all spirits to stay out of his domain, otherwise known as New York City, and especially the Avengers. Of course, Jack saw that as a challenge and visited often in an attempt to revive their friendly rivalry. He liked to think that Loki enjoyed their spars, both physical and verbal. It didn't really matter if he did. Loki was one of the few to see him; he wasn't just throwing that away.
*Father Frost is the badass Russian version of Jack Frost, who binds the world with ice chains. Basically, I'm trying to bring in some of the mythology surrounding Jack Frost.
Speaking of which, I'm going to explain some of the stuff in the chapter, like where I got Jokul Frosti from. I went online to try and figure out the origins of Jack Frost. From what I saw, the Nordes had Jokul Frosti, who was the son of a Nordic wind god, was a cowardly guy, blah, blah blah. Long story short, when the Nordes went to England, the English bastardized him into their own version, which is the one we know now: a winter sprite by the name of Jack Frost. There's a buttload of other winter spirits too, which I may or may not bring in. I dunno, I just like the idea of Jack and a bunch of winter spirits hanging out and griping about how they don't get any respect and nobody likes them.