Tony didn't see it coming. Thinking back, he really should have done. Things had been going so well; they hadn't had any problems for months. And things always went wrong.

Still, it didn't normally go to hell quite this drastically.

..

It was a regular day. There was a meeting on board the helicarrier: nothing major to be worried about. Fury insisted on giving them briefings every now and then to keep them all in contact. Tony had a theory that he only called the meetings because he felt left out of the little get-togethers the team had every weekend or so.

After the whole Manhattan fiasco, the team had gelled in a way none of them would expect. Tony and Bruce were thick as thieves; Banner had moved into Stark Tower at the billionaire's insistence, something along the lines of: "I have much better labs than you'll get in Mumbai, or wherever you're planning on running off to, so don't even think about it Hulky!" Thor and Steve had developed a strange connection, probably borne out of the fact that they were both strangers to this world; Steve was out of his time and Thor... Well, he was just in the wrong dimension. Clint had finally manned up and asked Natasha out on a date (which may have ended up with them both running for their lives from a manic scientist with a grudge against S.H.I.E.L.D – Clint was still apologising) and they now seemed to actually be in a relatively stable relationship. The rest of the team was secretly thrilled for them.

For once in his life, Tony really knew what he was meant to do. And more than that, he loved every minute of it. Well, almost every minute.

The meeting was dragging, and it was all Tony could do to stop himself from marching out the room to try the new algorithm he had been devising since he sat down. He thought he might have found a way to massively boost the power output of the arc reactor without frying himself, and he desperately wanted to try it out.

"Stark, are you even listening?" Fury's irritated voice cut through his complicated mental calculations and for a moment he just blinked at the one eyed man who was his sort of boss.

"Err, of course." He took a glance at the screens behind the director, trying to work out what they had been discussing. He came up blank. "It all sounds... Very... Interesting?" He tried to pull off an innocent smile, but Fury saw right through it and glared harder.

"Do you have anything to add to the conversation?"

"Umm... not really. More of a listener, me." Steve sniggered from across the table and Stark shot him a death glare. The soldier ignored him.

"Care to tell us what you were actually thinking about?" The director shot at him with a sigh, used to Stark's short attention span. The only time he ever saw the man concentrate was when he was in his lab or in his suit.

"Unless you lot all want a speech on the finer points of quantum physics, I can guarantee you won't be interested." Stark responded with a shrug. Banner gave him an interested look, but for the most part the others looked blank. "I'm trying to find a way of increasing the amount of power I can get to the suit from this thing," he tapped the glowing circle on his shirt.

"I thought the last time you tried that you almost blew yourself up?" Natasha questioned, sounding a little too gleeful at that prospect than Tony was really comfortable with.

"I may have done. But I got a lot of data from that. I have a better idea on what variables to expect now," he replied with a shrug. He looked at Bruce and caught the man with a calculating look on his face before he noticed the scrutiny and smiled. "I was hoping you could help me. My knowledge of what to expect biologically is woefully limited." He produced a faux expression of heartbreak and the irradiated doctor nodded in agreement with a grin.

"That's true," he replied, much to Clint's amusement, who tried to cover his snort with a cough. Needless to say, he was unsuccessful. Tony just sent a glare at them both.

Fury was watching the billionaire with interest, partly intrigued as to how he could increase his powers as Ironman and partly amused by his interactions with the team. He had originally assumed that he would be the odd one out of the group, their weak link, but in fact he appeared to be the opposite. His easygoing, boyish nature seemed to balance out the drama and the carnage quite well.

"Well," he said after a moment. "You may as well go and get working on that, seeing as you're not going to listen to me either way. All of you, dismissed." The team rose, snickering as Tony shot towards the door and was down the corridor before most of them were on their feet. Banner followed after him with a fond sigh and a shake of his head. Curious, Thor went after them both.

Steve and Fury wandered off, discussing something about tactics and evil supervillains that to the rest of the world seemed incomprehensible. Clint caught Natasha in an embrace before she could leave, planting a kiss on her forehead. She smiled at him, wrapping her arms around him and pulling herself closer.

"Chances on Stark blowing himself to bits?" She offered with a wicked grin. He smirked.

"With Banner around, not as high as I'd like." They were joking of course, but the billionaire had somehow become the centre of all ribbing the team could produce. Tasha chuckled, pulling him towards the door.

"We'd better go and increase them then."

When the pair reached the lab Thor and Banner were stood off to one side watching Stark dash around the lab like a mad man. Tony had insisted that the labs given to him and Bruce when they had first arrived be left for them even in their absence, so that in instances like this he didn't have to return to the tower to start tinkering.

"I thought you were meant to be helping," Clint muttered to Banner as they joined them. Stark remained oblivious to their presence, focussed so entirely on his work. From the multitude of screens he had supplying him data the assassin was frankly impressed he was able to keep up with it all.

"I thought that for now it was best to just stay out of the way," he replied, just as Stark tossed something over his shoulder that shattered on the floor, muttering something about giving out the wrong frequency.

"Probably wise," Tasha put in as something else went flying. Stark and invention tended to lead to utter disarray.

"Aha!" Came a sudden shout and Tony lifted a glowing arc reactor into the air, showing the others.

"That was quick," Banner said, coming forwards, skirting around the debris on the floor.

"The upgrades aren't too complicated, just a little bit... sensitive. I had to cannibalise parts from some of the spare reactors I had on the ship, but I think it should work out." He shrugged as though this couldn't potentially kill him. Bruce just glared at him in disbelief before taking the reactor from him and running a few tests of his own.

From what he could tell, the device would give out massive amounts of electrical energy without the huge surges of heat the last prototype had introduced Tony to. It seemed safe enough so he gave the device back to the billionaire.

"Just... Be careful." Tony smirked at him, looking completely calm.

"Aren't I always?"

"If Pepper were here, she'd slap you for that remark," Bruce observed, finding he sort of liked that mental image. Tasha snorted.

"Good thing she isn't here then," he replied scowling.

"I'm more than happy to fill her role," Natasha volunteered, stepping forwards hopefully. Tony backed off rapidly, wary of the approaching assassin.

"Actually, I think we'll be alright thanks!" He dashed behind a desk. Clint wasn't even bothering to conceal his amusement and even Thor looked like he was trying not to laugh. "You all suck," Tony griped to himself.

Putting the prototype on the desk in front of him, he began to unbutton his shirt, revealing the glowing reactor lodged in his chest. He still found it strange looking down and seeing the blue circle embedded in his chest even if it no longer alarmed him as much as it once had. Bruce had moved closer, ready to intervene if this went wrong. Stark was mildly touched at the concern the doctor showed when he put his life on the line to test his theories. No matter how many times he explained that it wasn't like he had access to other willing volunteers or even past experience to draw from, Bruce was still determined that there must be a safer way.

"Ready?"

"For what exactly?" Banner replied sardonically. Tony just chuckled.

With practised ease he removed the arc reactor from his chest, switching out the old and implanting the new one as soon as he could. Once it was safely in place, he looked up at Bruce as though the doctor knew what to do now.

"So?" Bruce said after a second of silence.

"Well... I don't know. It doesn't feel any different." He shrugged carefully, feeling as though he had just strapped a bomb to his chest. Maybe this wasn't the best idea.

"Should it?"

"If it works like it's supposed to... no. Not until I put on my suit."

"And if it doesn't work?" Tasha was watching him warily as though she half expected him to spontaneously combust.

"Last time it started to feel really warm straight away. But it could present in other ways I suppose. Right now, it doesn't hurt, and I'm still alive. I'm calling this a win." He smiled at the others, who were still watching him like a time bomb. "Seriously, I'm alright."

"Maybe you should wait a while before trying the suit," Banner suggested. Tony grimaced. He knew it was the logical course of action, but he was like a kid on Christmas with a new toy. He wanted to try it now.

"But we won't know if it works until we try it," he argued. "I could sit around forever waiting to see if it blows me up."

"You said it yourself, any problems could manifest in a number of different ways. Give it an hour, that's all I'm saying." He looked at Tony pleadingly and the billionaire found he couldn't resist the puppy dog eyes. They reminded him too much of Pepper when she was asking him to be careful.

"Doctor's orders?" He smirked. Bruce smiled back, knowing he had won the argument.

"You bet your ass."

..

The avengers were gathered in a rough semi circle around Stark's suit. He was staring at it longingly whilst Banner ran some quick checks to make sure Tony wasn't about to drop dead: heart rate, temperature, blood pressure.

"I'm fine Hulky. Let me fly," Tony whined, trying to pull away. Banner glared.

"Thor has already told you that he's not going to catch your ass if you fall, meaning you need to stay conscious. Forgive me for trying to make sure you don't die. And don't call me Hulky." He snapped irritably. The others chuckled softly but said nothing. They had grown used to the strange banter between the two and for the most part they ignored it.

"You love it. Are we done?"

"Fine, go kill yourself," Bruce sighed, withdrawing. "Just don't expect tears at the funeral," he warned. Tony laughed, walking to his suit and activating the machine to put it on him.

As the last piece slid into place, the team collectively held their breath, not really having any idea what to expect. Tony for his part could feel his heart racing. He started imagining heat radiating from the reactor, but he knew it was still as cool as ever.

"How do you feel?" Banner looked concerned but didn't approach.

"I... Don't really feel any different . No unbearable heat. That's good right?"

"You're asking us? It's your machine," Clint replied, sounding mildly exasperated. Tony shrugged at him.

"It's not like I've done this before either. This is sort of uncharted territory." He let his mask slip into place and tentatively told the systems to activate. Without hesitation the suit came to life around him with slight whooshing sounds as the hydraulics turned on, and a brief flash of light as the screen in front of him lit up.

"How about now?" Tasha asked looking more interested and less concerned than the others. He smiled at that.

"Power at over three hundred percent sir," Jarvis' automated voice informed him, effectively answering the assassin. "All systems are fully functioning."

"Thanks Jarvis," Stark replied, breathing out a relieved sigh. "I think... It might actually be alright." He laughed aloud, relief flooding through him in a rush until he felt weak at the knees. With a start he realised he hadn't actually expected this to work. Maybe Pepper was right and he had no concern for his own life.

"Are you going for a flight then?" Banner asked, still looking unsure.

"I might as well try it. I've gotten this far. Jarvis, are all flight systems online?"

"Ready and waiting, sir."

He hesitated only for a second before letting his instinct take over and launching himself into the air. He hovered above the team for a moment, just making sure before twisting and whizzing towards the bay doors at the end of the hangar. They groaned open at his approach, just wide enough for him to slip through and then slamming shut behind him.

Out of the cover of the helicarrier the wind was far stronger than he had anticipated. It blasted him sideways, and for a moment he floundered, falling as he struggled to readjust his stabilisers.

"Having problems out there?" Clint sounded suspiciously like he was laughing. The others had told him that they would watch him from the observation desk and they had obviously felt the need to steal some communicators.

"I'm fine, thanks," he snapped back, finally correcting his calculations and coming to a standstill. It was strange, the theory of the flight was the same, but his calculations were way off. His thrusters were so much more powerful now that it was almost as bad as starting from scratch.

"How's the reactor holding up?" That sounded like Bruce.

"I'm not on fire. It's strange – I definitely have more power than before." He showed off for a moment, whizzing round almost too fast for the eye to follow.

"Impressive," Thor admitted in his deep voice. The demi-god was a man of few words, and fewer still were compliments. Tony took it as a high honour to be praised.

They spent the next few minutes like that, Tony playing with different functions on his suit and relaying any information gathered to the team. Bruce had somehow hooked up a computer to the sensors in his suit and could monitor his vitals remotely, and had taken to commenting on any fluctuations, quietly moaning at Stark for deciding to go for a test flight miles above the ground.

"As fun as this appears to be..." Came Fury's voice through their communicators. All of them jumped, and Tony had to react quickly to stop himself falling out of the sky. "I'm going to have to call this meeting short. We have a job for you. On the outskirts of New York there's a... beast. I'll send you the coordinates but you all have to go. Now."

"Beast?" Tony asked in confusion as the others scattered to gather their weapons.

"That's all I know." The director sounded worried. "Your mission is to take it down, and if possible find out where it came from. For now the damage is limited, but reports say that it's heading into the city."

"Hawk, you're flying the others in, right?"

"Yeah, I'm heading to the jet bay now." He sounded like he was running.

"I'm faster in the suit. I'll go ahead, try and work out what it is we're dealing with here."

"No!" Banner yelled at him, and Tony jumped again. "You need to switch out your reactor!" There was worry filling his voice and Stark was once again touched by the affection behind it.

"I'll be fine. I'd have to test this one at some stage anyway. There isn't time for me to come back in. I'll see you in a few." With that he twisted and sped away, not waiting for a response. Behind him, the entire team froze for a second, staring at each other in the realisation that one of their team members could be in serious trouble.

..

I hope you like the start :) This should only be two or three chapters, and they should be coming out fairly rapidly. I think :S Tell me what you thought :D