Author's note: This started as a prompt from a good friend; Lost to the Hoping. But Tony and Bruce took over and who am I to object to all this cuteness? No overt slash-just Science Bros at their best. I hope you all enjoy. Please read and review.

~~~xXx~~~

Sacada:

Tony always liked music. He was a being of energy, of movement and action, it seemed only natural that shied away from quiet, from stillness. He leaned towards loud, percussive, sounds that echoed at least three floors above and below his labs. The complaints of his teammates always seemed to fall on deaf ears ("You can't hear yourself think? Good, your thinking is distracting.") In the end, Natasha would retreat to the library to work on her missions, Clint usually made the roof his base of operations, and Steve often fled the tower all together. Pepper Potts, long accustomed to her boss's quirks, merely continued her daily job duties armed with a sturdy pair of earplugs and a scowl.

Only Dr. Banner stayed, hunched over his tables and simulations and papers, seemingly oblivious to the pounding rhythm that nearly shook the entire lab. If he didn't complain, he certainly didn't seem to revel in the musical stylings of AC/DC or Lynyrd Skynyrd either. But that was fine, so long as Tony could continue his work unmolested, he didn't particularly care.

The months seemed to slip by, almost unnoticed by the residents of the Tower. There were missions of course, a terrorist plot discovered in Wyoming (though half of the time was spent convincing Stark that cowboy boots would not count as "going undercover"), sabotage to a nuclear plant in California (the Hulk had a field day on that one), and countless other missions that seemed to blend together until they were just another mundane distraction from Tony's work.

The others found other ways to fill their leftover time. Natasha began collecting intelligence on a shady collection of former USSR officers, Clint usually tagged along, or else ran miscellaneous missions for SHIELD, Steve joined a gym. They flitted through, more or less unacknowledged by the genius until he finally resurfaced from his experiments—an event that might not occur for days. It wasn't that he disliked them; Steve was a hell of a basketball player, Clint shared his love of B-rated horror movies, and he was still trying to beat Nat in Call of Duty—but they were temporary companions at best. Tony had learned long ago that friendship was fleeting, that no matter what, everyone leaves.

And yet, some how, he never expected Bruce to. He'd invited the scientist to stay after dust settled in New York, batted away every feeble excuse as to why he might not exactly be welcome, built him his own work station without asking (complete with a Banner-specific panic room near by.) It honestly never occurred to him that the scientist would actually decline him, and Tony Stark was very good at reading people. Banner stayed.

He never used his own lab though, choosing instead to set up a cramped makeshift little lab bench in the corner of Tony's own lab. And at first it bothered Tony—he never liked having people in his lab "looking over his shoulder and wasting time with useless questions." Not to mention the dangers of testing potential new weapons while another person stood nearby, just begging for a piece of shrapnel to the chest. And besides, Bruce's eschewing of his shiny new lab was a personal affront to the billionaire. Bruce practiced in a damned hut before this and yet a state-of-the-art lab was somehow not up to his exacting standards? But after weeks of pointed questions, of possible upgrades and adjustments, Tony just gave up and resigned himself to having a new lab partner.

Which turned out to be surprisingly not awful. Bruce was quiet for the most part, his experiments far less likely to explode than Tony's and he patiently tolerated the rants that followed said explosions. And Tony, who'd never truly had a peer, learned just how nice it was to have a second set of eyes. ("You forgot to integrate the third equation—I think that would help with the lag you've been struggling with.") As the months slid by, Bruce's presence had become less of a distraction and more of a comforting constant, and it was easy to believe that it would never change.

So when it did, Tony Stark was completely unprepared.

It started with a clatter, loud enough to overcome the music, loud enough to pull Tony's attention from his newest suit. He looked over to see Banner, mild mannered Dr. Banner, leaning against his desk, his shoulders heaving as broken electronics sparked around his feet.

With a wave of his hand, Tony silenced the music and took a hesitant step forward. "B? Everything okay?"

"Fine." The scientist's voice was rougher than Tony was used to, but there was no undercurrent of "the other guy"—he was in control then. Tony took another step, careful to avoid the scattered debris of technology.

"Come on, Doctor. Let's go get a burger. We could both use a break," his voice was softer, gentler than few had thought him capable of.

Bruce let out a breath, and his shoulders seemed to curl inwards for a moment as though he was collapsing in on himself. Finally, he straightened and by the time he turned around, there was little hint of his outburst.

"I'm fine," he said with a wry smile. "Just a lack of sleep and an elusive answer to my ongoing problem, nothing to worry about."

Tony was about to retort that nearly 15 million dollars of his wrecked equipment was a tiny bit more than nothing, but something in Banner's eyes stopped him. "Okay, fine, nothing at all," Tony replied with a smile of his own. "Why don't I take a look at what you have so far? I'm sure between the two of us—"

Bruce's smile widened, but he only stepped back, hands up in a clear sign of retreat. "Not now, Tony. I just need some time to regroup," he looked at the mess and dropped to his knees. "I'll just clean up and—"

Tony dropped a gloved hand to the other man's shoulder. "Don't worry about the mess," he said, sympathetically.

Bruce smiled awkwardly in thanks and swept to his feet. "Thank you, Tony."

Tony watched him flee and sighed, gesturing for Dummy to begin the clean-up. With nothing else to do, he returned to work, and the music returned with a careless gesture. The screams of guitar, the rhythmic pound of drums filled the silence, rushed into the void left by Dr. Banner.

And yet, somehow, the lab seemed quieter than before.

Tony hated it.

~~~xXX~~~

Afternote: if you stick around, I promise some serious fluff next chapter. Also, if you're a fan of fun facts, "Sacada" in Tango means displacement-more specifically the leg of one partner displaces the non-weight bearing leg of the other. Seemed fitting-but who is displacing whom, I wonder?