All recognizable characters belong to their respective owners (Marvel, Universal).

Set ambiguously in Marvel movieverse, and season 1 in Eureka.

"No, no, wait, Fargo. I thought you just said you'd accidentally let a giant robot slip out of a video game and into reality. That wasn't what you said, was it?"

"Um. Yessir."

"Great," Nathan Stark sighed. "No, wait, let me guess. It's made of some indestructible metal, and also has enough firepower to take out all of Eureka."

"No, sir," Fargo said, brightening at being able to give a negative. "Well, yes about the metal, it's vibranium, see, it's-you're not interested. Right, well, actually it's got enough artillery to take out, uh. The entire west coast?"

Nathan sighed. "I hate you," he said conversationally. "Fargo, I hate you so much. Call Sheriff Carter, and Allison. We're gonna need them."

Fargo left at twice his usual speed, downtrodden. As well he should be, because seriously, this was bad. Nathan didn't specialize in impossible robots or fighting large metal things bent on wholesale destruction.

Luckily, he knew a Stark who did. And that was the real reason he hated Fargo just now, because oh, but this was gonna suck so much.

He picked up his phone and dialed a number he'd long since memorized. Not Tony's, because one, Tony rarely answered, and two, it was impossible to know what number he was using at any given moment. Mostly because he'd lose his phone, decide it'd be quicker to build a new one, set up a temp connection through his AI and then forget to port his old number onto it.

"Hello?" greeted a sweet female voice. "Who's this?"

No name, he noted, because if you were calling her personal cell instead of her work one, you'd damn well better know who you were speaking to. "Hello, Pepper," he answered. "It's Nathan."

"Nathan! Hey, nice to hear from you. What a surprise."

"Wait," said another voice over the phone, one he knew well. The sound was quickly muffled, as if someone had placed a perfectly manicured hand over the microphone. If it weren't a StarkPhone, that might even have made a difference. "Nathan? Like, Nate-Nathan? My Nathan?"

"He's not yours, but yes, that Nathan," Pepper answered, then took her hand away. "What can I do for you, Mr. Stark?"

"No!" Tony said loudly in the background. "No, no no no, give me that, you don't get to say that to anyone else ever, that's only for me, give me the—Nate! Hi!"

Nathan closed his eyes. "Hi, Tony," he answered wearily, already worn out just listening to the much more excitable Stark. "Hope I didn't interrupt anything important."

"Actually-" Tony started.

Nathan cut in, because he'd meant that as a nicety, not an apology. "I kind of have a problem I was hoping you could help with."

"Ooh, what kind of problem? Technical? Engineering? Women?"

"Please, Mr. Stark, don't listen to Tony on that subject, ever."

"Pep, hey, Pepper, that was mean, I'm good with—um. Okay, sorry Nate, what was your problem? Something Eureka-specific?"

Nathan didn't want to know how Tony knew about Eureka. Well, okay, he was pretty sure Tony had hacked some files he really shouldn't have when Nathan was reassigned, but he never wanted confirmation because he was really enjoying his plausible deniability, thanks.

"More or less," he admitted. "It's more the indestructible robot of doom kind of problem."

Tony made a happy noise. "I can be there in about four hours. No, Pepper, you go to the meeting thing, no one'll miss me, they never do. How indestructible are we talking here?"

"Well," Nathan answered. "What do you know about vibranium?"

"No, nope, wait, back up. You have a giant robot made of vibranium? Nate, you are my favorite, my very favorite; it isn't even my birthday. I'll be there in two."

Nathan raised an eyebrow at the phone. It was a skill he'd cultivated carefully during college, mostly because it pissed off Tony because he couldn't raise a single eyebrow. It was a wasted effort without the other there to see it, but it was also habit.

"Do you-" he started, but there were noises and shouting through the phone, and then a loud thud that Nathan recognized as the sound of the phone hitting the floor. He waited a second, and after some rustling, Pepper said, "Sorry about that, Nathan. He's on his way."

"Oh, joy," he muttered, and said, louder, "Thank you, Pepper. You're a saint, has he told you?"

She laughed, low and amused. "He hasn't, no, but everyone else does. Hey, do me a favor and send him home in one piece, please?"

"I will do my level best, Miss Potts," he promised. Which was no guarantee, not when it came to Tony.

"Thanks," she said, and meant it. "Good luck with the robot. Let me know if I need to arrange for it to be brought back here."

He blinked. Well, it wasn't like they needed a giant decommissioned robot laying around, but why would Tony—dumb question. "Right," he agreed. "See you at Christmas."

"You too, Nathan. Bye."

He hung up, and went to see this robot for himself. It was currently thundering around in the forest north of there, but once it hit the edge of the forcefield around GD it would likely turn back towards town.

His phone beeped at him, and he checked to find a message from Tony putting his ETA at one hour forty two minutes. Well, technically it was from Jarvis, because the grammar was correct, the spelling was perfect, and it was nominally polite. Nathan set a timer for that time minus one minute; one could never have enough of a warning when it came to Tony. Then he sat back to watch the robot rampage.

It was quite impressive.

Fargo brought Carter and Allison out to the forest less than twenty minutes later. "Mr. Stark?" he started nervously, and Nathan twitched.

"You have one hour and twenty seven minutes to solve this," he announced.

Carter, because of course it would be Carter, frowned and said, "Fargo didn't mention a time limit. What happens then?"

Nathan leveled a stare at him. "That's when the tac airstrike I called in gets here."

"You did what?" Allison demanded.

"So do us all a favor and get this solved before then," he continued right over her.

"Right," Carter said, and flung him a nasty look. "I'm going to go call Henry. Fargo, you're with me. Let's try to find this thing's weakness."

"I've got the specs on my computer," Fargo offered, bouncing after him. "I, uh, it was designed with a theoretical metal so as to be all but indestructible..." His blathering was lost in the distance.

"A tacticalairstrike?" Allison demanded. "Do you have any idea what the fallout from that could do to the town?"

"Unfortunately, yes," Nathan murmured. "We might have to have Thanksgiving here." And he shuddered, because having Tony in town for any length of time would be a disaster. He'd fall in love with the town and its make-it-bigger-'til-it-explodes approach, and the thought of Tony and the residents of Eureka teaming up was sheerly terrifying.

"What?" Allison asked, completely confused. But Nathan was already turning to follow the others. Maybe he could get this all sorted before his last option showed up.

One hour later, that was looking less than likely.

"So, wait," Carter was saying, because he needed to stop every few minutes to recap everything. Seriously, couldn't the man think? Which was unfair to the sheriff, he knew, but with the clock ticking out, Nathan was not inclined to be nice. "So the only way to stop the thing is through the control panel, which is below the completely indestructible experimental metal, and also happens to be in the sole of the foot?"

"Pretty much," Henry said. "The problem is that no matter how hard you hit vibranium, it just ripples the impact out as, well, vibrations. Hence the name. Hit it with a big enough burst of energy, and you'd get a sound wave that'd level the whole town."

"Right," Carter said, "Hitting bad, got it. Wait, Fargo, how was it supposed to be beaten in the game?"

"It wasn't," Fargo answered miserably. "It was a fighting game, like, uh, Soul Caliber or Blazblue..." he trailed off, seeing Carter's blank look.

"Street Fighter," Nathan offered instead, and saw Carter's face light up. Seriously, you'd think the man didn't live with a teenager. Well, Zoe was by all accounts uninterested in video games, but still.

Ten minutes and counting.

Right.

"Okay," he announced. "Time to go back outside with anything you've got."

Fargo held up a small data storage device. "This'll stop it if we can get it in the slot on the control panel."

"Under the unyielding metal," Carter added helpfully. "On the bottom of the foot."

Nathan plucked the little plastic square from Fargo and bit his tongue to stop himself from retorting with something rude and crude. Nine minutes and change. Chances were, Tony was homing in on him, or at least his cell phone, so he'd best be near the robot. Instead of saying anything, he turned on his heel and strode out.

He didn't check to see if the others were following. It didn't matter.

It took them six minutes to get back out there at full speed, and he joined Allison in robot-watching.

"Call it off," she said wearily, and he shook his head.

"No other choice," he responded, then turned his head to acknowledge the sheriff coming up beside him. "Carter. Hope you like AC/DC."

There was a moment of bemused silence all the way around, and then Allison choked on nothing at all. "So when you said airstrike..."

"I meant it literally, yes," he answered. "Can you think of a better description for him?"

She shook her head in disbelief and said, "Nathan Stark, I hate you."

"Thank you, darling," he drawled.

"Wait a second," Carter broke in, and Nathan did. He waited two, actually, because that was how long was left on the clock.

The sheriff was still saying something, but Nathan was listening to something else entirely, and sure enough, there was the hisscrackle of the speaker system.

Thunderstruck this time. Eh, close enough.

There was the wooshboom of something traveling at mach speeds suddenly decelerating, and then something shiny and red dropped down at an angle, landing in front of them and skidding backwards from momentum.

Allison clapped a hand over her hair and yelped, Carter shouted, Fargo ducked and covered and Nathan shook his head. The armor straightened up from its crouch, and Tony's tinny voice said, "Hey, Nate! Great to see you again, let's catch up sometime, and can I say how much I'm loving the giant robot?"

Nathan sighed and reached out his arm. "One day you're going to do far more property damage than you're worth, you know." Tony grasped his arm gently through the armor, and Nathan flipped him the data storage device. "This code'll stop him. Control panel on the bottom of the right foot."

"Ooh, shiny," Tony said, and stuck the disk into a newly-opened slot on his arm. "Jarvis, we got it? Yeah, good. Okay, you folks may wanna stand back, and seriously Nate, I owe you a new car, this is fantastic." Behind his helmet, he must have been smiling like a loon. "Whoop!" he called out, and took off straight up.

They watched him go, then Nathan started heading back.

"That was Tony Stark," Fargo said faintly.

"Where are you going?" Carter asked, and Allison stepped forward doublequick, calling, "Hey, wait for me!"

"Tony's effective, but contained he is not. I'm not gonna be within a mile of this fight," Nathan said, and continued walking. Allison caught him up, and he offered her his arm. She ignored him.

"But that was Tony Stark," Fargo said.

"So he gets to call you Nate?" Carter asked, catching up to them and towing Fargo along.

"No," Nathan said. "But he also doesn't listen to me when I tell him not to, and then he buys me Aston Martins."

Carter took a moment to consider this argument, then conceded, "Good point."

"But guys," Fargo said again, still being dragged, "that was Tony Stark."

"Yes, Fargo," Nathan snapped. "Do try to keep up."

"Iron Man!" Fargo yelped, which was at least progress.

"Yes," Nathan snapped. "So let's get somewhere safe so he can fight your giant robot."

"I'm dreaming," Fargo mumbled. "This is a dream. This is too awesome to be real."

Allison glanced over her shoulder at him. "Should I punch you? See if it hurts?"

"I thought it was pinch?" Carter asked.

"It's Fargo," Nathan shrugged.

"Yeah, okay." If the sheriff didn't stop agreeing with him, Nathan might get a complex or something. Surely it wasn't healthy.

"Does it hurt when you agree with me?" he asked, genuinely curious.

"Yup," Carter answered blithely. "Breaks my heart a little more every time."

"Incoming!" Fargo said, and no one listened to him.

"Incoming!" Tony boomed, and they scattered, rolling and ducking as Iron Man sailed through the air they'd so recently occupied. He hit the ground and tumbled, sliding back a few yards.

"Tony!" Nathan called against all his better instincts, but dammit, he'd promised.

"M'fine," Tony waved a hand from his spot on the ground. His posture didn't look comfortable, or even anatomically possible.

"If you die, Pepper'll kill me!" Nathan yelled at him. "So don't you dare!"

"Nah, she wouldn't," Tony said, and fell out into a full sprawl. "Maiming, at most. Psychological trauma."

"I'm not testing her patience," Nathan retorted, but Tony was already getting up.

"Phew, that thing's got a punch on it," Tony commented. "Your design, kid? Good job."

Fargo looked about ready to faint.

"If you were a supervillain trying to take over the world, anyway. Better'n Doom, but not quite good enough. No worries, Nate; you won't see Pep 'til Christmas. Alleyoop!" And he was back in the air and back in the fight.

By now, there was a crowd at the edge of the building, people apparently hearing about the live-action fighting game happening on their north lawn. Their small group turned and joined them.

"Is that really-" someone was asking.

"-don't think it's really Iron Man?"

"-the detail of the pistons-"

"-repulsor technology? You think it-"

"That amount of maneuverability is fantastic-"

"It's Iron Man, it's Tony Stark," Fargo was babbling right with them. "He's amazing, it was amazing, the armor is modular, but it's so smooth you can't see the seams, he's amazing..."

Nathan tuned it all out. It was always like this; Tony was a celebrity, and whereas it was normally his charisma and wealth that drew a crowd, his armor was indeed a technological marvel, and here that went a long way.

Then Iron Man kicked up his heels and fell into a dive, straight at the thing's foot. His left foot.

"No!" Fargo was crying, "Wrong side!"

"Shut up," Nathan hissed, because it couldn't possibly be helping, and if Jarvis hadn't already pointed that out to Tony then Tony deserved to be stepped on.

Sure enough, the giant kept his left foot planted and raised the right to kick out at him. Iron Man attached himself to the flat bottom of the foot and appeared to be going for the control panel. The crowd was cheering, led by Fargo, and then the robot stomped his foot back into the ground with Tony on it.

There was no one there who didn't understand the calculation was not Iron Man versus vibranium, but Iron Man versus ground displacement, and so they didn't mourn prematurely. Instead, they waited, and waited.

It'd rained only three days past. Surely the ground would give before the suit?

The robot ground his foot down, twisting viciously. Nathan started to worry.

Then the leg stopped. Just stopped moving, stopped twisting, stopped anything. It was at an odd angle, but there was a mass intake of breath, and Nathan made a mental note that even hardcore superscientists weren't immune to the coolness of superheroes. Then again, he'd know; he'd grown up around Tony and his inventions, and the suit still gave him a thrill every time.

The foot that Tony'd gone under shifted, and started tipping backwards. A red streak flashed up from the grass and caught the thing's head before it could topple over. Then Tony did a backflip or two, making a slow loop around towards them.

His landing was much softer this time, and the first thing he did was flip up his faceplate. Then he raised a hand to wave at the crowd, and headed straight for Nathan.

"Hey, so, finders keepers? I can keep the robot, right? Because-"

Nathan braced himself for this argument. "Well, technically it belongs to Global-"

"Technically the Starks hold the patent for vibranium-"

"-untested design by a member of our staff-"

"-fully prepared to pay royalties-"

"Just like you to throw money at things-"

"Well, it keeps working, so..."

There was another quick minute of back-and-forth legalese. Thankfully Tony knew it for what it was; Nathan was covering his ass, not trying to deny Tony a present.

Finally having exhausted all his arguments, Nathan gave up. "Fine, it's yours if the subsidiary designer gives you the rights," he said, and couldn't help smiling. It was so nice to talk to someone who got both the business and tech sides of life sometimes. Even if that someone was Tony.

Okay, fine, especially if that someone was Tony.

Tony made a sound rarely heard from people over the age of eight, and yelled, "Hey, kid! Trade you my autograph for your dead robot!"

Nathan glanced over his shoulder in just enough time to see Fargo actually, literally faint.

End

...probably

i don't get it how is this not the most popular crossover ever?