A/N: I have been binge-reading Marvel Cinematic Universe fan fiction over the holidays, had my heart broken by the Civil War trailer and this is one of the results. The one-shot takes place before Captain America: Winter Soldier, Thor: The Dark World and Iron Man 3… Have fun!

Of Cats and Tongues

People firmly, almost stubbornly, believed that he was the more disciplined mind.

That alone amused Bruce Banner.

They saw Tony Stark's crass demeanor, his biting sarcasm, his escapades, his alcoholism and his burning desire to defy any authority figure that came across his way and translated it to 'undisciplined'.

Tony was right. People were idiots.

They tended to forget that the Other Guy had not created himself; that had been Bruce's doing. His own thoughts sometimes (often, always) scared Bruce, almost as much as his emotions, which could turn him into a raging green monster. His help in Kolkata and other places he had used to hide was given not only out of the goodness of his heart, or due to the need to redeem himself, but also to keep his thoughts at bay; thoughts on how to change the world with the help of science. He loved science more than anything, (his retreat into a landscape of logic and thought, a landscape that controlled the anger he had felt long before the Hulk) and he hated it, because it had wrecked his life. He would never fully trust it again, no matter how much he loved it.

Nevertheless, Tony had managed to banish some of said hatred and mistrust. The billionaire admired his intellect, challenged him on a daily basis, and had no qualms to point out whenever they entered a field (like nuclear physics) where Bruce surpassed him by length, and yet, Bruce was never forced to dumb himself down around Tony or even control his thought processes; it was exhilarating.

Given the man's public appearance (genius but arrogant and condescending of anyone unable to match his brainpower), it had been surprising to learn that the billionaire was an expert at rolling with the punch whenever encountering a new field of knowledge, and he learned so fast that Bruce was speechless at times. During one of their many conversations, they had once breeched the topic of histopathology. Tony had even stumbled over the term itself, never having given any thought to pathological changes in tissues as a result of illness be it due to infection, degenerative disease, or another letter from the MAGIC ADDITIVE surgical sieve. They had both stopped whatever they were doing and spent an afternoon on a computer where J.A.R.V.I.S had pulled up books and images on pathology. Tony was like a sponge that absorbed any kind of knowledge that came across his way. The next day, Tony was discussing fish parasites and the lesions each of them caused as if he had studied it for years indicating that he had absorbed everything Bruce had shown him and then used that as a basis to expand said knowledge to ridiculous proportions.

In truth, the self-control the man exercised on a daily basis was astounding. Put him in a workshop (anywhere actually), and he would create magic working tirelessly and meticulously with iron (no pun intended) discipline and determination. If it did not work, he would simply try again and again until he made it work. If there were something he did not understand, he would study it until he did.

What people also tended to ignore was Tony Stark's patience.

Yes, patience.

Tony Stark was a patient man, believe it or not. Bruce understood all too well that having to explain things to the rest of the world could cause frustration to the point of gritting your teeth. It felt like walking on the sidewalk but being forced to walk behind a person or a group of people several paces slower than you while unable to go past them. Only, imagine that happening every day and every time you tried to explain what you were doing. The SI heir was very, very good at explaining. He was a fast talker and that helped, but even that was not enough sometimes.

'Think before you speak' is very common advice, and while people tended not to say that around him fearing to make him angry (and because he did not talk much in general as well as due to him speaking as unhurried as possible to avoid agitation), he had heard every version of that phrase directed at Tony reaching from 'Tony, shut up!' to 'Stark, I may not be a dentist, but if you keep running your mouth, I'll knock your teeth out!' and it made Bruce furious. Tony never seemed to be particularly affected by it, thankfully, or Hulk would make an appearance to knock out the teeth of whoever uttered that particular threat.

The issue was not that Tony did not think before he spoke; the problem was his inability to formulate all of his thoughts into sentences. He was excellent at multitasking with several (Bruce still was not sure how many) completely separate streams of thought that could be combined at will, and sometimes Bruce' inner biologist just made him wish he could pick Tony's brain apart just to see the depth of what the man thought in the course of a minute or even seconds.

People also believed that Tony talked a lot, which was true, and most did not notice, but sometimes, there was a moment of silence, hesitation and a brief look of utter frustration. Bruce had seen that expression around the other Avengers at times.

Tony Stark could actually get tongue-tied. When those streams of thought wanted to be uttered simultaneously, but had not quite combined yet, it resulted in Tony jumping from A to Gamma within two sentences, not unlike what just happened.

'So, the acceleration of the arrows depends on bow length, material, draw… but Thor is not here.'

'What?' Clint laughed, confused and a little overwhelmed; Bruce could hear it in the agent's voice. He had been the object of Tony's complete focus for the past five minutes, and the physicist knew just how intense that could be. It was like being put under a microscope, casually taken apart and then put together with almost gentle care (and receiving some upgrades along the ride). Steve and Natasha, who had also been listening to the conversation, grinned and shook their heads at Tony being Tony.

It was just for a second, but Bruce could see the brief flash of hurt before it disappeared and the billionaire started babbling nonsense until his mouth was back on track with his brain and he steered the conversation back to archery.

Bruce could only imagine what the engineer had been thinking; he must have thought of Thor's hammer and the weapon's unbelievable capability of acceleration, or he had thought of Thor because he had just opened the kitchen cabinet noticing that pop tarts were running out, or something else entirely.

No, Tony Stark was a patient man. If he were not, he would have long given up speaking as fast as he did. People should stop insulting the man's impulsiveness when it was indeed his patience and discipline that kept him at bay, just like Bruce kept the Other Guy under control (and vice versa, ironically, as Tony had pointed out some evening). The only thing that controlled Tony… was Tony.

Bruce was also aware of what could shred said control to pieces: when the ones he held most dear were in danger.

If Colonel James Rhodes got lost somewhere in hostile territory due to insufficient information, the billionaire would hack any computer system on earth while simultaneously calling onto every favor he had until his oldest friend was found, before retrieving him while setting fire to whatever commanding center had been stupid enough to think Tony Stark did not have a heart, and then he would build something that would prevent anything like this from happening ever again.

The Other Guy may be able to rip the world apart and Bruce knew he could do quite a bit of damage with only his intellect (and it scared him in just how many ways he could wreck havoc on the planet if he made use of it), but Tony Stark could bring the world down to its knees with nothing but his mind; political and financial power notwithstanding.

The Avengers protected the world with their powers, but the only thing that protected the world from the Avengers was Tony Stark's discipline and his stubborn, reactor-enforced heart that had all the reason in the world not to care but refused to give up hope on humans that could not even begin to comprehend the sheer brilliance the man harbored.

A/N: I think everybody has those moments when there is simply too much going on in your head to properly put it into words. I am not a native speaker of English, but professionally it is currently the only means of communication I have… Trying to get your point across can be frustrating at times. I can only imagine how frustrating it must be for the geniuses in this or the complete off-the-grid super geniuses in MCU trying to explain what they are thinking on a daily basis.

A/N: Thanks for reading. Reviews are appreciated!