A drabble based on the dialogue prompt, "Don't look so shocked. I am who I am" for romanoffnotromanova.

She leaned back, balancing her weight in her heels so the small spark of pain centralized in her abdomen would have time to dissipate without further strain. She glanced over at her teammate. It had been a mistake for S.H.I.E.L.D. to send him with her. This wasn't his kind of work. He posed more a threat than their enemies had, and it was a liability she wouldn't forget any time soon. If only she knew her thoughts mirrored his.

If there was any indication of Bruce's disgust, she must have picked up on it. For now, he'd carefully masked the rising bile in the back of his throat and pushed back the terrifyingly close grip of the other half of his personality. Now would not be the time to lose control—not when the dangerous gleam in Natasha's eyes remained, darting to him when he shakily cleared his throat. He shouldn't be here. This was the last place they should have sent him. He was better off in the tower, puttering with his experiments and helping in the aftermath of any such events. Fumbling with his glasses and cursing his luck to be the only free member of the team at the moment, as well as the foremost expert of his trade, he tried not to notice the blood pooling on the floor beneath the still bodies surrounding them and instead tried to focus on the rest of the mission. He could let his emotions go later, after enough meditation to keep the Hulk silent. "We should go. I have the files and I don't think they're…" He made the mistake of allowing himself a glance at the nearest body, and he swallowed and willed his voice to come back. "I don't think they're in the position to stop us at the moment. Now would be the best time."

Natasha blinked at him, and he had to remind himself that she had just killed ten men because the persona she usually used around him and the rest of the team was a far cry from what he'd seen today, or even what he remembered from fragments of the battle in New York. The other guy surged against his walls and Bruce unconsciously tightened his grip around the small drive in his hand. A mistake.

She was looking at his hand when he realized what he was doing, and he slowly loosened his fingers. He was about to speak again when her voice cut quietly through the thick silence.

"You're sure that those are the files? This is the only opening we have. Anything after this, and it will be impossible to come back."

Not impossible, Bruce noted, but highly unlikely, and he hated the way she seemed to look straight into his soul to the darkness of the Hulk. No argument. He nodded. "Everything is here," he said, indicating the object that he was moving to push into the laptop bag he'd carried. It wouldn't do to lose it now.

Natasha was still staring at him, cold and calculating, enough to add fear to the mix of feelings threatening to break the wall in his mind. He'd had enough time to strengthen it, at least, and when she suddenly turned, stepping carefully around still forms of the last few unlucky men to stand in her way, he started not too far behind, ignoring the squelching sound of blood on tile as they walked past. They had been in and out quickly, no time for death without evidence. It was a clear enough message to send to their enemies, even if Bruce always hoped to avoid bloodshed. It was the nature of the beast, of course, and he couldn't fight what he couldn't control. He had a hard enough time as it was.

They reached the jet within five minutes and Natasha had it in the air within another four—four because of wing damage they sustained while landing under fire. He's been assured the jet would fly once it was in the air. No words were exchanged other than what was necessary and the entire trip back to the helicarrier was made in oppressive silence. Bruce took the time to shut his eyes and focus on the raging center of his mind, every technique he knew used to push it back to something manageable and less harmful than before.

Briefing began fifteen minutes after landing, only exchanging important information and the details of what they underwent throughout the mission. Bruce got his orders to analyze the data they collected. Natasha was to be sent on another mission—this time solo— somewhere that Bruce didn't quite catch. It wasn't until they both stepped into the hallway to go their seperate ways that Natasha stopped him. "You've been wanting to say something to me." It wasn't a question. How she could possibly know what was going through his mind, Bruce had no idea.

Now Bruce never claimed to be an expert on psychology, though he probably knew more than most, but the change he'd seen in the agent had been… The closest he could say was that it was nearly akin to his shift in nature when he allowed the Hulk free reign. He hardly recognized Romanoff, with the apathetic technique behind each individual fight, and the way she'd looked at him afterwards, as if he too was going to turn on her and she would leave him bleeding out the same as any of the others. He knew—or at least thought—she wouldn't. "I've never seen you fight like that," he admitted.

The way her eyes narrowed after the words left his mouth didn't bode well for him. "Don't look so shocked. I am what I am."

"I thought it was against S.H.I.E.L.D.'s policy to kill without purpose." The words were gone before he could stop them.

"You should know, Dr. Banner, that S.H.I.E.L.D does not dictate all of my actions."

"And they're okay with that?"

"I was doing my job and nothing more. What about you, Dr. Banner?" The unspoken 'when you've killed as many as the rest of us'. Honestly he should have expected it, because he and Natasha had never been particularly close and he'd nearly killed her before, and it was hard to place your trust in someone that could turn at any minute. He couldn't blame her. They both had their monsters to fight, and he didn't have the right to question her motives. He hesitated, trying to think of something to say, and when nothing came, he turned away with a muttered apology. He slipped his glasses from his pocket to sit on the bridge of his nose, suddenly the solitude of the lab and his research sounding much more promising than before.

"Good luck, doctor."

When he turned to return the favor, Natasha was gone.