Bruce Banner has better hearing than most humans.

It happened after he experimented on himself, a side effect he didn't even notice until months after the event. He had been just sitting in an empty room when he heard things clang from outside and had immediately to the window, heart racing.

Some kid had kicked over a trash can the next street over. He had heard it clear as day. But unfortunately, that discovery would have to wait because he was currently on the run from a government agency.

Since then, he's found it very useful.

Quiet, bustling towns tucked between mountains in China and slumped over sand-colored cities in India only annoy him. Pretending he's cold and bunching a scarf over his ears is plenty and then he can just travel like he wants, pretending that he can't hear whispered conversations about him the room over.

But when he hears the safety click off of a gun it becomes much more useful than he had thought.

Now he can find trouble before it finds him around half of the time. The other guy doesn't leave the agents alive long enough for them to figure out that he could hear them, and by that point he's already skipped off to the other side of the planet.

They never really learn, though their weapons get larger and larger every time they come after him. Ross, in particular, loves enormous grenades fired from helicopters that the other guy can flick away with his pinky finger.

It never hurts him, they never stop, and its settled into an almost predictable rhythm. Its about time for someone to find him again, and he's very, very, very far from surprised when the little girl disappears through a window and Natasha Romanov marches out to take her place, albeit more threateningly.

He's not threatened.

Sure, there are agents outside, but they can't take him, so he plays along. His cover is blown, he wants out, SHIELD is one of the nicer groups on his tail. She even makes up a little lie about only wanting him in an office instead of the other guy. He doesn't believe it for a second, but the sentiment is nice.

He's on a Helicarrier and meets the other members of their 'team'. The Avengers. That doesn't sound like someone who stays in a lab.

Thor - the man who likes to think he's a god but Bruce has his doubts. Steve - 'I understood that reference', dug out of the ice with nothing but a name, propaganda, and a shield. Natasha - a spy with words that try and trap him but he's already free.

And then Tony Stark, the genius, in person. They get along swimmingly, though there's a slight problem of him being stabbed. But nothing happens other than a joke thrown his way and Captain America getting threatened by a poke to the side. Honestly, Fury wouldn't have brought him aboard if he fell apart that easily.

Or maybe he would.

The one-eyed spy whose 'secrets have secrets' is difficult to get a read on, but Bruce gives him two-three days top to figure out what the man actually means when he says something.

Everyone has their tells.

But its after he's pounded Loki the other god into the floor and they've sent him back up to his world in the sky that something curious happens.

Tony invites them all to stay in his tower, grumbling about it being Fury's command. Everyone is suspicious and he fights back just so that they can all see him being timid and scared but he already knows he's staying.

Because once he had shifted back to himself and could process everything around him, he starts to hear things.

Of course, there's the steady hum of machinery that never dies and the gentle sound of voices drifting through the floor but that's what regular people hear. Bruce is very, very far from that.

He hears a click.

Everytime he walks into a room or exits one, there's a click. It takes him nearly a day but he's narrowed it down to three clicks, fast as lightning.

One-two-three, and then silence. He hasn't figured out what they are, but there's only one place to start.

The genius likes him, that much is obvious. They get along well and he even finds himself relaxing slightly as they play in the lab, ducking for cover when something goes wrong on either side. They laugh and laugh and Tony sends one of his bots to clean up before they start again.

But every time he walks into the lab, he hears those clicks.

One-two-three, silence.

He has to find a way to test it, has to find a way to prove what it is.

So he sets up base in the middle of the kitchen, accompanied by a tablet with one of his books pulled up on it. He's close enough to the door that he can hear everything, even over the thrum of the elevator.

Natasha is the first down. The doors slide open and she nods cooly to him, heading straight to the food.

One-two-three-four-five. He's stunned but doesn't make a show of it.

Clint.

One-two-three.

Steve.

One-two-three.

Tony.

Nothing.

He's all but confirmed that it's some sort of weapon, which explains Natasha. She and Tony have some history, and from what's he heard in short, quiet burst from their moments in the lab, it's not a pretty one. She did something to him and while he gives every sign of forgiving her, there are still five clicks.

Everyone else has three while Tony has none. He idly wonders what Pepper or Rhodney have, but doesn't have time to test his hypothesis. He's got to make a move against Tony and figure out what they are.

But he's got to be subtle about it. Can't just storm up and ask what protections he's got against every single Avenger in the Tower.

So instead, when Tony invites him into the lab, he waits by the door long enough to grab Tony's attention. He steps through.

One-two-three.

He steps out, waits, and then steps through.

One-two-three.

Then he walks over to Tony, who has a soft smile on his face. He turns his head toward the ceiling, lips quirked self-deprecating. "Lock the doors and blackout the windows to here. Override protocol 0-3-3-3-3-5, okay? Keep it slow, J."

Bruce is nearly quivering. He finally gets to figure it out, and it doesn't take him long to figure out what the string of numbers for the protocol is. Each of them, Tony first with Natasha last. Everyone else is a three.

But what does three mean?

He gets his answer as three tiles flip open and retract upwards, sliding smoothly into the cracks of the ceiling. Something shifts inside, moving slowly as they emerge from the darkness and come into light.

Machine guns.

Three of them, polished to perfection. Magazines stretch higher into the ceiling, all completely full.

And each one is perfectly aimed at the middle of his chest.

The other guy roars to furious rage at the sight of them, blasting inside of his skull. He winces and shakes his head, throwing the guy off, even for a second. "They won't work on me, you know." He tries for casualty.

Tony bobs his head. "Yeah, they will."

The machine guns slide back up into the ceiling, tiles covering up the space and sliding back into place so seamlessly that he's hard pressed to even find where they had been at all. They had just disappeared.

They stand in awkward silence before Bruce presses, does the opposite thing of what he probably should.

To his surprise, Tony opens up.

They were installed the second after Obadiah Stane died, the code is written for JARVIS in a flurry of late nights and coffee-filled mornings. Every machine is perfectly ready to use, and JARVIS does passive scans on each every night, more during difficult times. When the Avengers moved in, they were checked every hour.

Every person gets a standard three trained on them at all times. The tiles can retract in under 2.4 seconds and the guns are firing in another 0.3. Before Natasha, it had been nearly five seconds before reacting.

He remade the ceilings for every single floor until they were able to move as fast as possible.

Pepper and Rhodney only have one on each of them, and Fury has four. Whenever he's in the room they switch from passive to alert, but never to aggressive like with other people. He trusts JARVIS not to shoot him but even has overrides for if JARVS is ever hacked.

Bruce listens to it all, eyes growing wider and wider as he hears every word. This much paranoia and yet the man still invites them in, invites the person who literately stabbed him and the super soldier he hates and an expert bowman with too fast a temper and…

Him. The man with the other guy.

Tony brushes him off and then they get back to work, carefully pushing the thoughts from their minds. Tony's mind is a bee's hive that he isn't sure anyone on the planet is ready to poke with a stick, and here's the problem.

If he makes a mistake.

If he looks to others first instead of listening to Tony as well.

If he turns his back.

If he runs away.

Then Tony will fix his tower again until the clicks are silent, until he can't even tell how many are trained on him at all times. He imagines the stiff shoulder, the press smile, the darkened windows of the lab as he tries to gain access.

And so he pushes thoughts of a remote Switzerland town out of his mind and focuses on the now. They get along better than they had before, Tony pulling less and less fake smiles and casually dropping tidbits of information that he doubts the other Avengers have any ideas about.

In return, he does the same.

Tips about the other guy. What his thought process is, what he likes, dislikes, and what he actively hates. Problems he's had with him inside his head and then the quirks he has in his human body. His hearing is brought up, and Tony takes it with a twist of his lips.

But then there's a mission, and he's not the other guy. He's trying to patch up Clint's knee from when a building decided to drop a chunk of stone on it when Steve goes charging by, angrily shouting. He clicks on his earpiece and then there is Steve, yelling at Tony for something or other.

Something about civilians and how he should have gotten the monster away from the large building first.

Something snaps and then he's running, throwing himself in between them. He stares down the Captain with eyes tinted green and then slowly steps back, nodding his head to let Tony explain.

He brings up the fifteen lifeforms JARVIS had scanned inside another building the monster was heading straight for, and how he had saved them first before trying to attack it again.

Steve gapes.

But the next time Tony invites him into the lab, his ears hear something different.

One-two, silence.

He gives a soft smile in return.

Hey guys! Happy lil' oneshot for you guys to enjoy!

Well, not so happy.

But it's a one shot, at least. You can't call me on that!

I mean. I guess it's kind of in the same universe as Brains over Brawn but heyyyy, we don't pay attention to that, do we?

And yes, I'm being kind of mean to Natasha, but hey, Tony doesn't like her and that's what I needed. I'm not sure whether this is Bruce or Tony-centric, but I like it either way. I'm writing way too many of these to be healthy, especially with finals literately tomorrow.

But yeah, I'll be fine.

Just read this and enjoy! Tell me what you think.

Anyway! Please read and review!

Frost OUT!