By the time Harry had eaten a leisurely breakfast, packed up his camp, and gotten his horse over to where whatever-it-was had crashed, a whole lot of locals had already beaten him to it. There were pick-up trucks all around the crater. One guy had set up a barbecue, there was a radio playing, and more folks lounged on deck-chairs watching as their friends all tried their hand at lifting the thing in the middle like they were trying to draw Excalibur.

One old bloke backed up to the crater in his truck, and some younger guys brought out a long chain, which they used to tie the... absolutely massive hammer, Harry realised, to the back of the pick-up.

Rather than moving the hammer, the back of the pick-up was pulled off.

Harry smiled to himself and decided that he really did need – not just want, but need – to have a go at this bit of fun.

"You gotta be kiddin' kid!" one of the big, beefy guys objected with a laugh. "How do you think you're gonna pick it up when we couldn't?"

"Arthur managed to free Excalibur from an anvil when he was just a kid my age," Harry countered with a grin.

"Aw, let 'im try!" one of the women watching called out.

"It'd be a right laugh for all of us if the kid did it when even a truck couldn't budge the thing!" added one of her friends.

Harry was escorted down to the hammer. He'd just slipped his hand into the leather strap at the end of the handle when a whole flood of people in suits and combat uniforms descended, declaring the site to be radioactive, and that they all needed to leave. Harry sighed, and removed his hand from the leather strap without attempting to lift the hammer.

"Woah, except you," a voice said as a hand lay on Harry's shoulder before he could take a step.

Harry turned and looked up at the person who'd stopped him. It was the guy from Budapest. Harry smiled. "Hello again," he greeted.

"Agent Barton, why are you detaining that minor?" another man in a suit demanded.

"Boss, this is Harry Potter," the man, Agent Barton apparently, presented.

"Mr Potter," the suit-wearing man greeted with polite surprise. "I'm Agent Coulson of SHIELD."

"Shield?" Harry repeated.

"Strategic Hazard Intervention and Espionage Logistics Division," Coulson explained.

Harry pulled a face. "The acronym is definitely less of a mouthful," he agreed. "Umm... are you guys also going to be looking for the guy who fell from the sky just a bit before the hammer did?" he asked curiously. "Because he's probably still at the local hospital after he got tased by a very pretty brunette."

"A man fell from the sky?" Barton asked, a little incredulous, even as he couldn't help but chuckle at Harry's hormones rearing up to describe a person of the opposite gender.

"Well, technically he's an Asgardian and he came by the Bifrost, but laymans terms will say man-slash-alien, and fell from the sky works as a pretty good description of what it looked like when it happened last night," Harry explained with his best, innocent smile.

"An alien?" Barton questioned, now a lot incredulous, rather than just a little.

Harry shrugged. It wasn't magic, so there was no statute of secrecy covering his telling them about this.

"Indeed," another voice spoke up.

"Professor!" Harry greeted brightly. "Will I get an answer this time if I ask what you're doing here?"

"I am risking my very existence, Mr Potter," Loki answered seriously. "The name of this particular blonde and violent idiot is Thor. That," he said, and gestured to the hammer, "is Mjolnir, Thor's hammer. He'll come for it when he knows it is here, so you needn't look for him."

"May I ask who you are, and how you were able to just walk up to us?" asked the suit-wearing man, a hint of edge in his tone. "I know my men are already setting up a perimeter."

"Agent Coulson," Loki greeted, and inclined his head. "Of course you may ask. However, I cannot promise answers to all of your questions. As I have said already, I risk my very existence by presenting myself here."

The man in the suit frowned. "I don't believe we were introduced," he said. "So now I'm also curious as to how you know my name, as well as why you mean by 'risking your existence'."

"A conversation best held between just the two of us," Loki intimated. "Or three, if you would be so obliging as to contact Director Fury. But there are some things that I either cannot or will not divulge in the presence of one of my students."

"I'm confused," Barton admitted. "Professor?" he asked.

"Well, I go to school in Scotland," Harry started.

"And I teach one of the subjects at that school," Loki finished with a suave smile. "Agent Coulson, I am unarmed and only wish to share information with you that will be to the benefit of SHIELD. It is simply a case of some of the information I wish to share being very sensitive."

Coulson frowned, but nodded. "Very well," he agreed. "Barton, don't let Mr Potter wander off," he instructed, then gestured for Loki to lead the way to somewhere private.

"How'd you get all the way out here anyway Kid?" Barton asked.

Harry grinned and pointed to where he'd parked his horse.

~oOo~

Coulson indicated for Loki to climb into the passenger seat of his car, while he slipped into the driver seat. Once the doors were shut, Coulson pulled out his phone and called his boss.

"Coulson, is there some reason you're calling me again so soon?" Fury's voice asked, rather than extend any sort of greeting.

"An unknown approached me and knew who I was, and who you were, without being told," Coulson answered.

"And I have information," Loki added.

"Who are you?" Fury demanded.

"I am Loki," he answered. "And it would be wise for you to remember, Director Fury, that doors, even and especially those that reach to the other end of space, open from both sides. The Tesseract was sent to the bottom of the ocean for a reason."

"How the hell do you know about that?!" Fury demanded.

"Director Fury, are you familiar with the concept of a paradox? A statement that contradicts itself? I know who you are, who Agent Coulson is, and about the Tessaract because I have met you before, and it was because of the Tessaract that our meeting came about," Loki started to explain. "This won't happen for, I'd guess, another year or two though."

"You're saying that you have met us... in the future?" Fury clarified.

"That's right," Loki confirmed. "Though for me, personally, it has been some near-decade since then."

"Time travel?" Coulson queried.

"That's right," Loki confirmed. "And now here I am, risking my continued existence in this time-stream, by offering you information that will become very pertinent."

"Such as?" Fury asked.

"Such as... when we eventually meet for that first time, Director Fury, I will not be in my right mind, and will not be restored to my right senses until and unless the Hulk slams me into a marble floor enough times to leave me lying in a crater barely able to breathe from the pain."

"That sounds like a rather drastic sort of measure," Coulson noted.

"A normal human, such as Agent Barton, would be able to be restored from the same state as I was, or will be in, through nothing more than a solid strike to the temple," Loki offered. "There are certain disadvantages to being... in possession of a more resilient constitution."

~oOo~

"So that guy is one of your teachers?" Barton asked Harry as Loki and Agent Coulson walked away.

"My favourite teacher, actually," Harry corrected. "Yeah."

"You two look a lot alike," Barton remarked.

Harry nodded. "He helped me with my school shopping when I got my letter saying I had a spot at my school, and one of the shopkeepers mistook him for my father. I kind of like the idea, and he didn't correct her either."

"Problems at home?" Barton queried gently.

Harry shrugged. "I wouldn't know," he admitted, then smirked to himself. "I haven't been back to my aunt's house for going on five years."

"Aunt's house?" Barton repeated, a confused frown on his face. "What about your parents?"

"Dead when I was a baby," Harry answered dispassionately.

"Sorry Kid," Barton apologised.

Harry shrugged again. "I don't remember them," he admitted. "I found out a couple of years ago that I've got a godfather, and he told me some things about them, but he's really only okay in small doses."

Barton chuckled. "I know a few people like that," he agreed with an easy grin.

Harry nodded. "So I've been, I suppose, 'on the lamb' for a while, going to school at the right times but otherwise travelling the world on my inheritance and dodging social services at the same time."

Barton barked out a laugh. As one who had run away to the circus as a kid, he could completely understand where that was coming from.

~oOo~

"Mr Potter, you are a P.O.I."

"As long as I don't become a P.O.W."

Coulson actually smiled a little at that. "Mr Potter, would you be interested in working for SHIELD?" he asked.

Barton blinked in shock at the question.

Harry smiled in answer to it.

"You wouldn't have to worry about the Statute, all of our agents live by it. They don't know everything it covers, naturally, but a lot of SHIELD's agents don't even exist," Coulson continued.

Harry's smile became a mad grin. "I've got to get my OWLs before I can leave Hogwarts," he said frankly. "And I am very interested in pursuing my NEWTs and further study in Runes and Potions."

Snape being a git didn't preclude the subject being damn useful.

"Owls and newts?" Barton asked, confused. The poor man's question was ignored.

"Of course," Coulson agreed. "In the mean time, you can sign our confidentiality agreements, and Agent Barton can help you get started towards our minimum fitness requirements."

"Oh, and Agent Coulson? The trick to dealing with Tony is to give him paradoxes and impossible problems to solve now and then. Genius brains get bored very quickly," Harry advised with a cheeky grin before he followed a still slightly stupefied Agent Barton away.

Behind them, Coulson chuckled softly.

~oOo~

After leaving New Mexico, Harry went to New York to visit with Tony. He was building a tower there, and it already had his name on the outside of it. The Research and Development labs were also the first to be properly outfitted – and that included being heavily reinforced.

Harry was introduced to Pepper, who thanked him profusely for saving Tony's life in Afghanistan, and then promptly dragged down to R&D so that Harry could have a look at the things Tony had been coming up with thanks to the things Harry had written to him about. Some of those things had originally been from Dr Banner's letters to Harry, and some of them had occurred to Harry while he was in class at Hogwarts.

Like the question of 'how does a bit of rock turn lead into gold and make people immortal?'. That was something that had been bugging Harry since he'd heard about the Philosopher's Stone. Tony was still working on that one. After all, how does a person get an Elixir of Life – or of any sort at all, for that matter – from a stone?

It didn't consume all of the man's time though. He was an engineer, not a chemist. Well, he could be a chemist, he certainly knew how to make explosives, but engineering was his main shtick.

Then it was back to the UK and Hogwarts, where things were getting weird.

Apparently, while Harry had been away having a grand old time in America, learning from Agent Barton how to be a SHIELD agent in New Mexico and then hanging out with Tony and Pepper in New York, the Ministry had decided that they needed to declare Albus Dumbledore a liar, and protest vehemently that Voldemort was not, in fact, back.

"So, they're burying their heads in the sand," Harry declared when Hermione showed him the newspaper, "and the Dark Tosser is an issue again."

"How d'you figure Harry?" Dean asked curiously.

"They wouldn't be making such a massive fuss about the whole thing if there was really no threat," Harry explained with a shrug. "They're running around like headless chickens, hoping that if they deny loudly enough then their wishes will come true."

"Besides, our magical neighbours on the continent are taking the threat seriously," Fred stated plainly.

"We got word from Charlie in Romania," George added, explaining how they knew.

"A celebrity was killed," Lee pointed out. "And our ministry is pretty much the only one that pretends the best rather than preparing for the worst."

Neville nodded in agreement. "They've been cutting the Auror budget a little more every year since the war ended."

"Right. In that case, I'm going to apply to take my OWLs over the Christmas hols and get the heck out of the country before New Year," Harry decided.

"What?!" yelped the Twins together.

Harry shrugged. "I actually got offered a job over the summer, and I only came back because I need my OWLs. If it's only our ministry that's being this stupid, then we'll all be safer in another country," he explained.

"Right," Dean agreed. "Don't think I'll be ready for my OWLs before the end of the school year though," he admitted.

"Neither," Neville agreed.

Hermione's face contorted in thought. "I'd feel better about passing if I had the full academic year under my belt too," she finally said.

"Well, we've got ours," Lee said with a gesture between himself and the Twins. "But I'll stay to the end of the year at least, keep an eye on you three."

~oOo~

"What do you think of our new Defence Professor, Mr Potter?" Professor Loki asked lightly when it was just the two of them in his classroom.

For Harry, Runes was the last class of his first day back in the castle, and he'd stayed back to talk to his favourite professor about his intent to get his OWLs before the calendar year was out – which meant he'd need to work faster on his project for Runes, which would necessitate spending more time in Professor Loki's classroom. The man was still quite strict that they only work on their projects under his supervision.

"I'd say she puts me in mind of a toad, but that would be insulting to toads, Sir," Harry answered honestly.

Professor Loki smiled, and chuckled softly in answer. "Yes," he agreed fondly. "Madame Umbridge is rather horrific. Now, what did you wish to talk about?"

"Well Sir..." Harry began his explanation.

Loki sat back in his chair when Harry was finished. "Ah," he said, and considered the teenager before him thoughtfully. "I am impressed by your ambition," he allowed, "and your reasoning," he added. "Very well. I only really leave my office for meals and staff meetings during the term anyway."

"Thank you Professor."

~oOo~

Despite the best efforts of Madame Umbridge and Headmaster Dumbledore, Harry was out of Hogwarts with all of his OWLs by New Year. Professor Snape had been almost as helpful as Professor Loki in getting Harry ready to take his tests. Professor Snape's justification was that, with those tests passed, he would never have to teach Mr Potter again, which suited him just fine. Even if it did see his employer rather put out with him.

"Mr Potter," a voice called.

Harry stopped in the Entrance Hall. He'd been on his way out, ready to start his life under his own power completely, free of any obligations that he hadn't specifically chosen himself. He turned to see his favourite professor walking up to him.

"Professor Loki," Harry answered with a smile.

"Mr Potter, you're leaving Hogwarts now, I think we can dispense with the title. My name is simply Loki."

Harry frowned slightly. "Sir?" he asked, confused.

Loki chuckled. "Truly, Mr Potter, I have no other name but that one," he confirmed. "If I may treat you to a meal at The Three Broomsticks?" he requested, a discomforted expression flitting across his features. "There are some things that I really must tell you, if you are intent on joining that organisation."

Harry blinked. "Alright," he agreed, and the two walked together through the snow down to the village of Hogsmeade.

"A private room, Rosmerta, if you please," Loki requested when they entered the popular tavern. "And a hearty meal for both Mr Potter and myself."

"Up the stairs, first on the left," the woman answered obligingly. "Food'll be up in five."

"Mr Potter," Loki started when the food had been delivered and their privacy was made certain, then he hesitated. "Harry," he tried again. "Do you remember, by any chance, your initial reaction to the revelation of your magical heritage?"

"Hagrid told me," Harry recalled. "It was all pretty shocking. Went against everything I'd been told up 'til then."

Loki nodded. "Well, what I am about to tell you is likely to be just as shocking, if not more so," he advised. "You are familiar, from my classes at least, with the concept of an anomaly."

Harry nodded in confirmation.

"I am a temporal anomaly, Harry," Loki explained. "More than that, I am also not human, however much I look it."

Harry blinked at that as he assimilated that piece of information, then scrunched his face up slightly in thought as he attempted to process it. "Not human how, Sir?" he asked.

"I am under the impression that you had a brief encounter with Thor?" Loki countered, letting that be his answer.

"You're an Asgadian?"

Loki shook his head. "Unfortunately, though I was raised under that belief, I am not. The revelation of my heritage, and a number of key events that immediately preceded and followed that revelation, caused me to... go off the deep end, I believe is the most apt description for what happened," Loki explained, and huffed silently to himself at the irony of that particular description of his mental state at the time, especially in light of events that followed. Like falling from the Bifrost.

"What does that have to do with you being a temporal anomaly Sir?" Harry queried.

Loki sighed. "I did something very, very wrong, Harry," Loki admitted with quiet solemnity and clearly in utter confidence. Harry was not to share this. "Back on Asgard. After that, I spent a few months as a captive to both my insanity and an ancient titan. Not one of the Greek or Roman inventions, Mr Potter," he added with a smile. "A far more real, and far more terrible creature. Following my release from the company of this titan, my attentions were turned to Midgard, Earth. My insanity continued to rain destruction down on the world I found myself in, but I was defeated. Insane villains always are, it seems," he added with a sardonic, but grateful, smile.

He shook the sentimentality off in short order.

"Harry, while a team of other people may be the ones who shall be instrumental in my defeat, it will be have to be you who is instrumental in making sure that the paradox of my existence is fulfilled safely," Loki explained quickly. "I may be subdued and freed from a terribly potent version of the Imperious by a great green beast of a man, but you are the one who must send me back through time. I will take responsibility for my crimes, but the past near-decade I have had, time which allowed me to seek therapy for my insanity, Mr Potter, as well as make your excellent acquaintance, is very necessary. When the time comes, I will take the place of my past self after you have sent him, me, back in time."

"How will I do that, Professor?" Harry asked, willing to not ask about the fact that he was essentially going to be helping the man escape punishment for apparently ten years. It was a time paradox. It had to happen in a certain way.

Loki pulled a thick, heavily bound book out of thin air with a gesture. "The spell you will need is on the first page. You must complete it over me while I am still unable to move, it will make everything easier. When that is done, I shall present myself to whatever mercy may await me," he answered solemnly.

Harry accepted the tome with equal solemnity.

"Mr Potter," Loki said, not releasing his hold on the text. "You must also send this book back with me. It has an account in my own handwriting. If I do not have this when I am sent back, then the results could be as catastrophic as if I am not sent back at all."

Harry nodded. "I understand, Professor Loki," he agreed.

Loki sighed. "Thank you, Mr Potter. I apologise for laying such a burden on your shoulders, but I cannot be in the presence of my past self. To do so would risk my continued existence in both time-streams. It could well risk the time-stream itself."

~oOo~

Dodging the aliens and the shrapnel was difficult, but not impossible, and he had his apparition licence, so once he knew where he was going and could visualise it, Harry was able to disappear off the streets of New York, reappearing on the balcony of Stark Tower. Stark Tower, where he had seen Loki be knocked out of the sky into the top floor. Stark Tower, where a great green man Harry knew as both Dr Bruce Banner and The Hulk had gone in, and come out again not long after, a satisfied air about him.

Stark Tower, where Harry found the man who would some day become his favourite teacher lying in a crater in the marble floor, wheezing in pain.

Harry opened the book that Loki had given him, and looked over the spell one last time before he closed it up and set it on his mentor's chest, pulling Loki's hands over the book, to make sure that the man would have it with him still when the spell was complete. Then he withdrew both of his foci.

Loki disappeared without a sound.

He reappeared without a sound too, mere seconds later.

"It's done," Loki said.

"It's done," Harry agreed, and hesitated.

"Yes, Mr Potter?" Loki asked. "I can see that you have a question. Best ask it before you burst."

"Will I ever see you again?" Harry blurted out.

Loki's eyes, as green as Harry's, softened. "I hope so, Harry," he answered. "I hope so."

Harry nodded, hesitated another moment, then dashed forward to embrace the man who, despite everything that anybody else might have said or thought, had been the most important male role-model in his life, even if he'd only had the man in his life – and that quite tenuously at times – for the better part of seven, nearly eight, years.

"Thank you," he whispered. "For everything."

Loki lay one hand on Harry's head, while the other arm wrapped around the teenager in a tight, protective, affectionate hold. "It was my genuine pleasure," he answered softly. "Now, I'd best make myself ready to be apprehended, I think, and make-believe that I haven't had ten years to anticipate the moment where I shall be held accountable for my crimes. Harry?" he called gently, looking down at the teen in his arms – Harry wasn't standing at his full height as he held tightly to his mentor, allowing for this. They were quite the same height now.

Harry looked up.

"Don't look," Loki begged.

Harry nodded, and released his hold on his father figure.

~The End~

Incidentally, Voldemort was killed by Draco Malfoy shortly after the blonde graduated from Hogwarts. The young man rather took exception to having his mother threatened by a man with a muggle father (he'd researched the ritual that brought Voldemort back to life, as well as checked out the graveyard where said ritual had been conducted, and found out the truth for himself) and no nose to boot.

(Ron Weasley, who had fostered a distinctly unfriendly rivalry with the blonde, had almost had a conniption fit over the other boy's sudden 'hero' status.)

And, yes, Harry was reunited with Loki, eventually. There were a few tears, especially when Harry asked Loki if he could call him 'Dad'. Loki had managed to choke out a 'yes', before the (by then) grown man wrapped him up in a tight hug.

A/N: to find out what happened to Dumbledore, please refer to the companion one-shot Mischief Mastered. Thank you.

Excellent Omake by rowanlyn-mirrim

"So thank you for having me read up on my Norse mythology Professor Loki. This wouldn't be near as funny if I hadn't."

"Indeed Mr. Potter. Though I do wonder how long it will be before Thor finds his hammer." A tiny smirk pulling at the corners of his mouth.

"More time then it would have if he hadn't been an arse when I met him." Said Harry smoothing into a full blown grin.

"Whatever do you mean Mr. Potter?"

"Oh, I got to the hammer first, its in my trunks living room."

Harry and Loki start laughing maniacally.