Hi everybody! "The Avengers" is finally out on whatever type of disc you prefer, and I've finally managed to finish some Avengers fanfic that I've been working on between other stories all summer. This one-shot concerns Tony and Bruce; I love Science Bros., both for romantic fics and friendship fics, so I'm really happy that I finally managed to finish this. It is, FYI, a friendship fic, although Tony does take his shirt off, so that's rather nice. :) (Right now, two of my three Avengers fics feature shirtless Tony…hmm, what a crazy random happenstance. :)) If you get the chance, please review, and thanks for reading!

Disclaimer: I own nothing of the Marvel universe; I do, however, own Tony and Bruce dolls of my own creation. :) (They're very cute and not at all creepy, I assure you! :))

Science Projects

It would have been the understatement of the century to say that the past few years had been strange. After living most of his life as the world's foremost billionaire playboy, a rather surreal existence in and of itself, Tony Stark had thought he'd known from strange. That was before getting hit in the chest with shrapnel from a missile with his name on it (ouch, and usually he was a fan of irony), then waking up with a hole in his chest and an electromagnet inside.

Tony had hated the thing at first. When he'd built the arc reactor, that had been an improvement—at least he didn't have to carry a car battery around with him everywhere he went—but it was still an unpleasant feeling, that constant weight in his chest, and the light that reminded him that he was still alive. Most of the time, that seemed like a good thing—not all the time, but usually.

After a few months of living with the thing, he'd gotten used to it, or at least it had ceased to bother him the way it had initially. It became a tool like any other—not that he'd want a screwdriver or a soldering iron embedded in his chest, but still. It powered the suit and managed the important task of keeping him alive. As long as it was useful, he couldn't really complain about the arc reactor—at least, not without sounding gauche, even by his own impressive standards for tactless comments and behavior.

For a long time though, he'd hated showing it to anyone. He'd showed it to Obie, and look how well that had turned out. Pepper was the only woman who'd gotten a good look at the thing, and even after they'd started dating, it had taken a while for her to convince him that she wasn't as creeped out by it as any sane person would be. Then again, Pepper had put up with him for so many years now that insanity on her part was a distinct possibility. Tony was grateful though; it was a relief, not having to hide the thing from someone. Then he'd met Bruce, and the good Dr. Banner had become another person who wasn't alarmed by the arc reactor so much as curious.

Of course, Bruce wasn't always around—he had his own ways of trying to save the world, which usually involved practicing medicine on the other side of the planet, in countries with names that many people couldn't even pronounce. But whenever Dr. Banner was free, Tony was glad to have him visit. Especially right now, since he was bleeding.

"More safety gear would probably be a good idea next time," Bruce said drily, staunching the flow of blood from a gash on Tony's arm. "And maybe more than one blast shield, just for good measure."

"Yeah, thanks—duly noted," Tony said with a wince. "Usually, the new alloys I test don't fail quite that catastrophically."

Bruce frowned as he cleaned the wound and prepared to stitch it up. "At least you got off with just a piece of metal in your arm. You could put an eye out, working with projectiles like that."

"Not likely, since I was wearing safety goggles and sitting behind a blast shield, though, as you pointed out, that failed too," Tony said, watching Bruce sew up his arm and feeling very grateful for painkillers. "Honestly, I didn't just invite you over to provide first aid, I promise. I've been playing with a new method of energy signature detection that I know you're gonna love, and…what? Please don't make that face while you're holding something sharp attached to a thread attached to my arm."

Bruce had suddenly gone pale. "Sorry, it's just…there's a hole in your shirt."

Tony glanced down and saw what Bruce meant. Probing inside the hole, he found a small shard of metal stuck in the face of the arc reactor. Tony whistled.

"Wow. Really glad this stopped it. I'm pretty sure I've got enough shrapnel in my chest already." Grabbing a pair of pliers, he yanked out the shard of metal and tossed it on the desk. "There. No harm done."

Bruce smiled faintly. "I'm really glad that you aren't slowly bleeding to death from an injury you didn't feel. Do you have much scar tissue around that thing?"

"Nope," Tony said quickly. "I mean, the initial injury was cauterized pretty quickly, so…" That particular memory was a nasty one, punctuated by flashes of pain too intense for Tony to really remember at all, though it wasn't as though he'd ever tried. That was a part of his mind that was too dark, too intimidating for even him to feel comfortable contemplating.

Bruce raised his eyebrows. "Can I, maybe…see it?"

Tony sighed, stepping back and pulling his shirt over his head. "I should have known that you were too much of a scientist to resist a chance to actually look at it eventually."

"Well, your descriptions have certainly piqued my interest, and since you're the only person on the planet with an arc reactor embedded in your chest…wow."

"The only person, as far as we know," Tony said with a shrug, trying not to laugh at Bruce's absorbed expression as he stared at the arc reactor. It always struck Tony as a fascinating contrast, the way that inside the brilliant scientist and skilled physician was the world's most dangerous science project. Tony told him so now, and Bruce chuckled.

"You're a pretty volatile science project yourself, you know. I'll bet the side effects of having an arc reactor involved with your cardiopulmonary system are pretty interesting, and mostly positive."

Tony smiled, grateful to have a friend who could actually relate to messed up science misadventures localized within the human body. "Trust me, you have no idea."

"Whoops, should I have knocked first?" Pepper called, smiling quizzically as she entered the lab.

"No, because you know that I would never cheat on you with someone who has more chest hair than I do," Tony said, pulling his shirt back on and not mentioning that he would sooner take more shrapnel to the chest than ever cheat on Pepper.

"That's very comforting, thank you," Pepper said, giving him a wry smile. "Dr. Banner, if Mr. Stark has been exposing himself without your permission, feel free to contact our legal department. They've been getting restless lately, now that there are, sadly, so few supermodels and actresses filing paternity suits against our esteemed CEO."

"None of which I was ever found to be the father in, so," Tony shrugged, marveling once again at his ridiculous good luck—even the arc reactor, in a roundabout way, was proof of his overall good fortune.

"Thanks, but I kind of asked him to—for scientific reasons," Bruce said, smiling. "Wow, that sounded creepy."

Pepper smiled. "I've heard and seen much creepier in this lab, I promise."

"The price you pay for dating a human science project," Tony said, smiling brightly when she handed him a contract to sign.

"Well, you're worth it," she said, retrieving the signed document, "provided you two can get through the day without blowing up the house."

Tony and Bruce glanced at each other.

"We can—"

"Yeah, we can probably…not do that."

Pepper smiled as she left the room. "Just be careful, all right? No more stitches today."

"I will try to keep that in mind, thank you," Tony called after her, sighing as Bruce cleaned his first aid supplies but left his bag within easy reach. Tony knew from experience that he shouldn't make promises regarding explosions or grievous bodily harm, but still, it might be nice to be able to from time to time.

"So," Bruce said. "What's this thing with energy signatures you wanted to show me?"

"Back here," Tony said, motioning toward the other side of the lab. "And I think I can safely say that I won't blow anything up this time."

"Really?" Bruce said dubiously.

Tony shrugged. "There's a thirty percent chance. Maybe forty, at most."

Bruce chuckled. "Well, we both know that risk and scientific progress go hand in hand. Let's see it."

Tony smiled. He was always happy when Bruce visited, because in addition to their shared status as weird living science experiments, they clearly shared a love of discovery, particularly if pyrotechnics were a possibility. "Check this out."