It started like this:
"God-fucking-dammit," said Steve, in an outburst of cursing that went above and beyond even what he'd occasionally use on the battlefield. "Can't any of you - look, I'm not asking for much, and you can roll as many bowling balls as you like down the locker room corridors and I don't even want to know what the foaming purple goo is on Bruce's desk, but for fuck's sake can we please sit through one single briefing where everyone acts like the professionals - like the adults - they fucking well are?"
Everyone was so surprised at the speech that they did, indeed, sit through the rest of the briefing in professional silence, only breaking for intelligent questions and relevant suggestions.
It helped that Tony was in medical nursing three broken ribs and a minor concussion throughout.
"Look, I know perfectly well that we're not all soldiers," said Steve afterwards. "But random comm chatter nearly got Tony killed today. It's not even the first time and I honestly expected better of two of you at least."
He fixed a glare on Natasha and Clint that was half-way between utterly disappointed and barely contained fury. Clint sucked in a breath. His shoulders suddenly had a tension that suggested he was an inch away from saluting. Natasha's face closed off - people who didn't know her would have said she simply assumed a serious, professional, no-nonsense expression. People who did know her would have said that all the life went out of her. Steve was too caught between worry and frustration and anger and a need to get them to all stop acting like - like lunatics set loose in an ammo dump - no, that wasn't fair either - but either way, Steve didn't really notice anyone's reactions. All that comm chatter had kept them all distracted, and he should have had an eye on Tony above him instead of yelling at the others to knock it off, and then that psychic shockwave had happened and half a building had hit Tony from behind and he'd fallen.
Not far - nearly on top of Steve, in point of fact - but far enough.
Steve's hands were still shaking. If it had been Clint or Nat they would not have survived. Hell, even he probably wouldn't have survived. As it was the armour was trashed.
"You're right," said Natasha, so suddenly that Bruce's angry retort was cut off completely. "It won't happen again."
Steve nodded curtly and left. His angry silence lingered.
When they told Tony his hand fell onto the table top with a smack that made everyone jump and jarred his ribs. "Fuck him," he said "I'll out-professional Captain fucking America, no fucking problem. Ouch, ouch, ouch."
It did, at least, bring a smile back to Natasha's face.
"That was unnecessary," said Thor.
Steve emptied his clip into the target - perfect cluster of shots around the herat - before he took the headphones off and turned to his friend.
"Was it," he said, "Prince of Asgard. I have met the Lady Sif and the Warriors Three, you know."
Thor shrugged. "They are warriors, born and bred," he said. "Our friends are not all, as you so rightly remarked."
"They need to learn a few tricks of the trade if they're going to survive," said Steve. He felt like snapping. It was a damn effort not to.
He felt, if he was being honest with himself, the way he had that first day on the helicarrier, when Tony's jokes had kept crawling under his skin and lodging there, when anything that opened his world up wide and threw him off-balance was a thing to be feared, because he was trapped alone in a time he neither knew nor understood and couldn't see what it was he was balancing on; if he came off it, even for a second, he'd be lost forever.
"They have done quite well for themselves so far," said Thor dryly and left him to it.
Steve didn't go back to Avengers Tower. He slipped off to Brooklyn for a week instead, hiding in the dingy apartment SHIELD had let him have after he'd woken up, playing Springsteen too loud and ignoring the voice in his mind that suggested, every now and then, that he'd been an idiot, and that he ought to just go home and tell the others they could block the comms with as much chatter as they liked. It was his own fault for letting their voices and words distract him in the first place. He was a super-soldier, he had better concentration than that. It definitely hadn't been fair to put it on Nat and Clint like that.
It was a voice that sounded a lot like Bucky's, and thus was easy to push aside. He and Bucky had always been good at preaching at one another - especially the things they didn't practice.
Steve was a stubborn son of a bitch. Protocols, like chains of command, were there for a reason. He was happy to break them if you had good grounds, but a three way argument between Bruce, Clint and Natasha over strawberry milkshake versus chocolate was just not one of them, and never would be. Bruce didn't even have the excuse of being the Hulk at the time.
Their next briefing went so smoothly that Coulson gave them all suspicious looks. The mission was an utter success as well. Everyone was crisp and calm and professional, and they got done in record time.
Steve was immensely, utterly relieved.
"Guys, that was perfect."
Afterwards, Clint said, "Hah!" darkly. "Project Adulthood is a go, people."
Tony disappeared into his workshop that night. Everyone else was sort of subdued, but Steve told himself it was nothing, and acted like nothing was wrong. They all watched TV and chatted for a bit, and then went to bed.
By the fourth week, the third flawless briefing, Coulson had graduated to fingering his sidearm and twitching whenever someone said something sensible. Tony hadn't worn anything but a perfect suit in three weeks, even in the workshop (the way Howard had), and had attended meetings and made proposals and spent so much time in R&D that Pepper was beginning to look uncomfortable. Bruce had been spotted in an actual lab coat. Clint hadn't folded a paper aeroplane in forever.
But the team was running like clockwork.
Steve hadn't had a one-on-one conversation with any of the others since - well. He hadn't talked to any of them about anything other than work or the weather since then, either.
Worst of all, Natasha hadn't smiled once in all this time.
And yet. Three missions in a row was the longest they'd ever gone without some kind of injury, mild or serious, on at least one of them. The now-permanent knot in Steve's chest was a small price to pay for the kind of efficiency that guaranteed his people's safety.
He knew, after all, how to be - he had practice at this. At being - he had. Quite a bit of practice, Bucky notwithstanding. There had been a before Bucky. (Apparently there was going to be an after the Avengers.)
He'd be fine as long as they were fine.
It was no worse than missing the Commandos, than missing Bucky and Peggy. That ache had (never) faded away.
This would too.
Goddammit, he'd really fucked this up.
"Well, I'd've said it was an improvement," said Maria. "Personally."
"It's not," said Steve. "I had no idea how much it would not be an improvement. I mean, nobody's got hurt in forever, which is so much of an improvement I can't even tell you, and we're functioning like a well-oiled machine, but -"
"You don't like well-oiled machines?"
"The Commandos were professionals," said Steve. "To a man. All of us. Peggy most of all. And the first thing I did as Scout leader was open a tab and promise her I'd take her dancing."
Maria patted the back of his hand, patronising, amused and concerned all at once. "You'll work it out," she said.
Steve didn't think so anymore.
Another week went by. Coulson became almost impressed with, but stayed conspicuously wary of, everyone's ongoing seriousness and sensible attitude. Maria got worried, rather against her own inclinations, as Steve got quieter. There was a set to his jaw that she just didn't like. He'd told her about Bucky once. She rather wished he was here now. She had the impression Barnes would punch him right out of this ridiculous mess and give the others a well-deserved lecture as a bonus.
Failing any way of achieving the right kick up the ass from probably the only person Steve would take it from, she went to Thor.
"This has got to stop," she said.
"He started -"
"Oh God, stop. You're going to be stubborn at each other until you drive each other into the grave, or the line of an enemy bullet."
Thor crossed his arms over his chest.
"Don't give me that," said Maria. "If Tony had been functioning at anything remotely resembling full capacity when this started they would have had an epic fight and not thought about it again."
"I - cannot deny that," Thor admitted.
"So go provoke a fight," snarled Maria.
There wasn't time - truly, there wasn't. Thor had just resolved to speak to Bruce about enlisting his help, if he was even willing, but Thor was sure he would be; Steve was not the only one regretting that they had let this come to this pass. By the Allfather, were they children, to be so cowed by him? No. Steve led them in battle, but he was a first among equals; they owed him no obedience beyond that, and certainly had not felt the need to demonstrate any in the past. The Lady Maria was more than right. In any other situation, Tony and Steve would have been tearing at each other within seconds: they would have shouted and accused and possibly even thrown an object or two, and by the next morning it would have been over. Something, somewhere, had just... gone wrong.
But before Thor had reached any further conclusions than that, SHIELD was attacked.
When he was small, his lady mother had used to say that there was a balance to all things in life. Tony called it a Newtonian law, action and reaction. Whichever terminology you chose to use, Thor knew long before he arrived in the debris-littered west wing of HQ that Steve would be injured.
"I'll tell you fucking why," Tony bellowed, just about ready to start jumping up and down in the corridor outside medical. "I was being professional is why -"
"We sat through the goddamn R&D meeting instead of skipping it like we usually do," said Bruce, pale-faced. "We never sit through the weekly R&D meeting. If we'd been here sooner - the suit would have picked it up. Jarvis' sensors. The bomb."
There was a horrified silence. Then Natasha started to laugh.
"Oh God," she said. "Jesus, I can't do this. I give up. He's an idiot -"
"He's our idiot," said Clint. "Also, like, barely thirty, people make mistakes, it's our job not to listen to him when he gets like this. Did we all get infected with Tony's concussion, what the hell."
"Seconded," said Natasha.
"The collapse of the building was caused by a pyschic shockwave," said Bruce. "No, what, I mean, thirded of course. Tony?"
"I'm going to break his kneecaps with a wrench and trash his goddamn apartment," said Tony, which everyone rightly took to mean yes.
Thor was rather relieved about this.
When Steve woke up - aching all over, pain flaring in his left arm, his left leg, much of his left side, resigned to the knowledge that no painkiller would ever work on him and he would just have to endure it - Natasha was asleep in the chair by his bedside, wrapped in one of Tony's hoodies.
Steve knew forgiveness unhoped-for when he saw it. He reached out, muscles screaming indignantly, and curled his throbbing, swollen fingers around hers before he passed out again.
Three days later, finally back home, he sat down to breakfast with everyone else, drew a tight breath, and said, "Guys, I'm so sorry. I've been an ass. I was scared and I took it out on you, and - I'm sorry."
"I'm sorry," said Tony. "I should've stoved your stupid head in then and there."
"You were barely capable of sitting upright," said Steve.
Tony threw the fresh packet of butter at him. Steve ducked, so that it hit the corner of the backrest of his chair and ricoched off into Thor's cereal bowl.
"So," said Clint over the ensuing racket. "Project Adulthood officially scrapped?"
"I think that's safest for all involved," said Bruce.
Not even Coulson could bring himself to mourn it.