Author's Note: This is a crossover between Iron Man and House MD. The Iron Man -part of the story is set in the movieverse, some indeterminate time after the movie, and as for House, it's set in Season 4, after House has selected his new team.

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Pepper Potts gazed anxiously at the sky. Tony had called an hour ago, he should here any minute now. The next minute, she scolded herself for being so anxious. There was hardly any reason for it. He'd only been gone for a week. He could manage a week without her. If he'd lose his passport or forget his social security number, he would call her— - which he hadn't done, so everything must've gone well enough.

She understood perfectly why he hadn't taken her with him: though officially it had been a simple business trip to the Stark Industries office in São Paulo, his main reason for going to Brazil had been to check out SI's new biotech center in the Amazon. There'd been reports of some kind of trouble there, possibly Iron Man -sort of trouble. He was determined to keep her out of that kind of trouble, so he'd decided he'd go without her.

The fact that he was returning in the suit instead of his private jet suggested that he'd found such trouble. He had been very brief when he'd called, he'd just said that he's near and asked her to wait for him at the windows giving to the pool, which sounded silly, but, of course, she did as he'd asked.

There he was now, a small red and gold figure high up in the sky and approaching fast. Her worry doubled when she noticed he was flying unsteadily, swerving from one side to the other as if he wasn't completely in control or quite sure of the direction. Drunkenly. That was the best word to describe his flying. But he couldn't be— - he did drink way too much, but he would never! She couldn't believe he would be irresponsible enough to wear the suit while under the influence.

As he got closer, she saw to her relief that the suit was perfectly intact. No bullet holes this time, nor scratch marks or burned spots or anything of the sort. But he still wasn't flying quite right, he was coming in pretty fast and where he was headed...

He covered the last feet so fast that she had just enough time to realize what was going to happen, and then there was a splash, as Tony Stark, alias Iron Man, landed quite ungracefully in his swimming pool.

She knew his suit had underwater capabilities, so she didn't panic quite yet, just stepped outside to be closer and waited. Sure enough, he climbed up from the pool and stood at the side for a while, unmoving, as if considering what to say. When he finally spoke, what he said took her by surprise.

"Miss Potts. Stay away from the pool. I want the whole thing decontaminated as thoroughly as possible. And don't come anywhere near me."

Pepper frowned, completely at a loss. Either he really was drunk, or this was some really weird joke, or, well, whatever else this might be, she knew she wasn't going to like it.

-- -- -- -- -- -- -- -- -- --

Dr. Lisa Cuddy marched through the lobby of Princeton-Plainsboro Teaching Hospital, moving as fast as she could while still keeping her dignity. She was worried that she'd been too slow and she'd be too late. She had to catch him before he left the building, because he might not answer his phone once he got home, and he absolutely had to take this case. It would be great for publicity, but only if they could handle it well enough, which meant solving the case, and he was the best man for the job. On the bright side of things, Cuddy didn't fear for one second that he wouldn't take it. He'd take the case with glee as soon as he saw what it was - —if only she could catch him before he left.

He was just about to open the glass door leading outside.

"House! House, wait!"

Dr. Gregory House stopped, not even bothering to turn around to face her. "There's this really annoying buzzing in my ears..." he muttered, as if to himself, but loud enough for her to hear.

"House, I have a case for you."

"No you don't. I've done a good day's work. I spent the last two days on a difficult case, I solved it, I've even done some clinic duty, there is no excuse that you can use to keep me here."

"Oh yes, there is. You'll want this one. You'll regret it if you don't take it."

"No, I won't." His tone was still as unenthusiastic as before, but at least she'd piqued his interest enough that he actually let go of the door handle and turned around. "Nothing in the world can be more appealing to me than a cold beer and a 'Prescription Passion' marathon."

"I'd bet you a hundred bucks that this is, but you wouldn't pay me anyway so there's no point."

"You're just too afraid you'd lose. All right, I'll look, and then I'll go home and you can give this," he took the file from her, "to someone else who won't have to work overtime on it."

He skimmed the file, still no feelings registering on his face except for not-so-mild annoyance. "So, someone's even sloppier than me at writing these things. There's hardly anything here to work on, and none of that is even remotely interesting."

"You might want to read the name of the patient."

"I don't care what he's called," House answered instantly, then read it, and there, finally, she got the reaction she'd been waiting for. "Oh my God. You've got to be kidding"

"I wouldn't do that to you, now, would I?"

"Would you? You'd get high doing it! But no, you're not this creative. This has to be the real thing. So, where is he?"

-- -- -- -- -- -- -- -- -- --

Tony leaned his armored head against the back wall of the cleanroom. He was sitting on the floor, partly because he didn't feel nearly sick enough to be lying down, partly because lying down in the armor was pretty uncomfortable.

He was overreacting, that was all. This was nothing. He was overreacting, and he was going to be so embarrassed when they found out that this was just the flu. He'd get loads of negative publicity, and that'd affect his company, but he didn't mind that. The most important thing was not to put anyone else at risk, so he had to be a bit overcautious and neurotic.

He'd spent almost an entire day in Brazil in self-imposed quarantine, fitting his suit with high efficiency air filters, even though he hadn't even felt sick at the time. Now he was sitting in said suit in the hospital in pretty much complete isolation. If this was the worst case scenario and he really wasn't overreacting, he sure wasn't going to spread it any further, whatever "it" might be.

He'd been waiting for an hour or so when the airlock-like door finally opened and a figure in a protective suit stepped in. He was limping badly. Must be the man Tony had come to meet. He sat up a bit more upright.

"Dr. Gregory House, I presume?"

"Wow, the Invincible Iron Man actually knows me?"

"I know a lot of pretty nurses, and you've got a reputation."

The truth was, of course, that he'd asked Pepper to find him the best diagnostician there was, and everything and everyone had pointed to Dr. House. The man had convincing credentials, although he allegedly also was a complete pain in the ass. Tony was starting to learn the truth of those allegations already.

"I do? Hm. Maybe I should take up superheroing too. I could call myself 'Superdoc'! Or maybe, if that's too obvious, how about 'the Cane'?"

"Yeah, really catchy and masculine. The girls would love that. I can just imagine what your superpowers would be like."

"Who says I haven't got such superpowers already? Of course, I couldn't compete with your legendary exploits, Mr. Stark. And you can take the suit off, everyone knows your secret identity by now, since you were kind enough to share it with the press."

"Not going to happen. I might be carrying something genetically engineered for biological warfare. It could be unusually contagious."

"The psych ward is upstairs. You're clearly suffering from severe paranoid delusions. There's no way you'll infect anyone while in here, suit or no suit, and no way we're going to be able to diagnose, let alone treat you through that thing. Call me when you've cleared your head," House declared and took a few awkward steps towards the door.

"I'm not going anywhere. I can send readings from my suit's scanners directly to your computers, you can start from there. Plus, the local authorities in Brazil are still investigating the biotech center that might be where I got this from, so they may come up with something sooner or later. Until we've got some kind of an idea of what this could be, the suit stays on."

"You really want to make things difficult, don't you? Fine. Mark my words, we are not going to have a solid diagnosis before you get out of that suit and we can examine you properly. Before that, we'll do what we can, but just because I love a challenging puzzle, and because you're Iron Man and it's incredibly cool to be diagnosing you. So," House made his way to the bed and sat on it. "Is there some marvelous superheroic story behind this mystery illness of yours?"

Tony really wasn't in the mood for House's wit, he felt dizzy and his back was killing him, probably from spending so much time in the suit. "There's a story, but it's not the least bit heroic, there's no supervillain, no action scenes and no sex."

"Boring," House sounded almost genuinely disappointed. "But let's hear it anyway."

"Long story short: I went to Brazil on a business trip, spent a few days doing business, and then went to check on my company's new biotech center. I'd heard there was something weird going on, and yeah, there really was. The head researcher was there to meet me, but the place seemed practically abandoned. He offered some half-credible explanation about a local holiday. He then gave me a tour of the facilities, which ended in a laboratory where he pulled a gun and redecorated the place with his brains. The next few days I spent cleaning up the mess and trying to figure it out. I only started feeling sick this morning when I was returning home."

"Well, that's not all that boring, though it sounds more like the X-Files than a superhero tale. Any particular reason you're so sure that you've caught a super-disease of some sort, except for the fact that you're a superhero?"

"No one was working on anything infectious at the biotech center, if that's what you're implying, but the guy's last words before blowing up his head were 'I'm sorry, Mr. Stark'. I thought it might mean something. But I'll make this clear: I'm not sure. I just don't want to take any risks."

"You've already made that clear, Mr. 'I don't want to take this suit off, I'll rather stay undiagnosed and die a martyr'. So, have you got any explanation for what was going on there?"

"None. I searched all the computers and came up with nothing, I contacted some of the researchers and they couldn't tell me anything useful, and the local equivalent of the CDC didn't find any unusual pathogens while I was there, but as I said, they're still working on it," Tony explained.

That wasn't all of it, of course. He wouldn't tell all the details about the whole mess to some random doctor, since they couldn't possibly be medically relevant. Not to mention that he really didn't have any sort of a theory yet, he just had a lot of data to go through. He'd figure this out and catch whoever was responsible, but he wouldn't be able to do that before he was sure he wasn't a walking biological weapon.

"'No unusual pathogens'. Hmm. That sounds a lot like 'It didn't come from there!', so we might want to consider all other options. Brazil is a big place, we'll need to know all the places you visited, who you slept with, what you ate— - and then, all the background: whether you've got any crazy relatives, evil twin brothers, et cetera, blah blah. I'll send someone to get a complete history with all the dull details I don't want to be bothered with." House got off the bed and limped out of the room.

Tony let the back of his helmet rest against the wall again. This was going to be a very long day.

-- -- -- -- -- -- -- -- -- --

"Symptoms so far include fever," House wrote on the whiteboard, "slight tachycardia and tachypnea which are most likely just situational, dizziness, headache, plus back pain and myalgias which are not surprising due to the fact that the patient has spent the best part of the last three days in a really cool iron suit."

House stopped for a while, studying his team. Nothing new or interesting there: Foreman looked skeptical, Taub mostly expressionless, Kutner excited and eager, and Thirteen was pretty.

House turned back to the whiteboard. "And let's add paranoia," he wrote below the rest. "The patient is in complete isolation but refuses to take off the suit because he's afraid he'll spread the disease anyway. That can't be healthy behavior."

Kutner couldn't contain his enthusiasm anymore, but chimed in, "We're really diagnosing Iron Man? Can you get a cooler patient than this?"

"Sorry to disappoint, Kutner, but I'm already convinced that no matter who he is, he's not going to be a very cool case. Differential diagnosis?"

"This could be anything!" Thirteen exclaimed. "The only symptoms that can't be explained away just like that are fever, dizziness and headache, and those could mean anything from the common cold to HIV."

"The common cold? But it cannot be!" House replied, though of course it was a very likely possibility. "The Iron Man can't have the common cold. At least it has to be the super-cold or maybe even the feared 'Titanium Cold'!"

"She's right and you know that, House," Foreman commented. "We'll need to check his blood for..."

House interrupted him. "Not possible as long as he refuses to take off the suit. This is all we're going to get. The good news is that we can get readings realtime from his suit's inbuilt scanners. The bad news is that all we've got is body temperature, respiratory rate, EKG and EEG, and whatever symptoms he can describe himself."

Foreman shook his head. "This is stupid. There's no way we can diagnose him based on nothing more than that."

"Oh really? I didn't know that!" House replied with his most ironic tone. "Of course we can't, and I already told him as much. I'm sure he'll take the suit off sooner or later, either when he stops feeling sick or when he gets too sick. We just need to wait. While we're waiting, humor me and come up with something that's more interesting than the common cold."

"He's been to Brazil, could be a tropical illness. Dengue fever?" Taub suggested.

"Realistic but not all that interesting."

"How about oropouche fever or chikungunya?" Thirteen tried.

"Good! Less common and with weirder names, so they're cooler. And both possible, too."

"Ebola?" Kutner put in.

"Let's not get too jazzy here. Last I checked, Brazil is not in Africa."

"No, but he was visiting a biotech center where they might've been working on infectious disease among other things, who knows what they've got there? And then there's the story about something weird going on there and a guy who apologized to Stark and then committed suicide?"

"Kutner, you're just humoring his paranoia. Though I'm sure he was lying his socks off when he told that Stark Industries has nothing whatsoever to do with biological warfare, I'd think he was telling the truth when he said that the local biohazard teams couldn't find anything like that at the complex. As to the story, all it means is that his company has some internal problems. I'm sure he hasn't told us even half of it and he's not going to, since it's medically irrelevant. So, let's just stick to the facts instead of fantasy."

"All these tropical disease are viral and there's no treatment anyway, so if it's one of them, waiting is still all we can do," Foreman pointed out.

"Yup. As I said, this is probably going to turn out a pretty dull case. The only reason Stark is here bothering us and not at home with the flu is that he's convinced he's the center of the world, and he's completely paranoid because of that. I'm going home. Let me know if something interesting happens."

After having seen Iron Man live, which admittedly had been pretty cool, House had gotten second thoughts about taking this case. Stark wasn't very interesting as a person, not much of a puzzle - —he'd been on the news often enough that House was convinced he had the man completely figured out already. So far he had seen none of Stark's allegedly keen intellect, and he doubted there really was any. Stark's reported three month captivity in Afghanistan had probably been just a publicity stunt. Stark was an annoying egoistical jerk just like House himself, but unlike House, Stark had convinced everyone, maybe even himself, that he really was a superhero do-gooder on a quest to save the world, while all he really cared about were the glory and the girls.