Natasha's P.O.V.
Two weeks after Tony shot Percy, the Avengers and a hidden son of Poseidon were standing in the middle of the Amazon Rainforest. Intel had informed them that there was some rogue soldiers and scientists developing some alien tech that had been stolen from the Battle of New York. Only one of the Avengers was aware that Percy was there, and that was her. He'd decided to watch over all of Natasha's missions. He had told her he had nothing else to do, anyways. Natasha was skeptical of that, as he was technically guarding Avengers Tower, but she supposed that he probably had some way of monitoring it.
The plan of attack on this mission was simple. Natasha would infiltrate the base, while Steve and Thor charged head on. Tony would get Clint to a good vantage point, and draw all reinforcements towards Steve and Thor. Clint would cover the other members of the team. That left Bruce to be their reinforcements if necessary.
At first, everything was going well. Natasha got into the base unnoticed. She could hear the sounds of gunfire through her comm as she moved through the halls. She took out several guards on the way. As she turned the corner into a hall, she noticed a scientist heading hurriedly in a certain direction. She moved to follow, and the entire hall lit up. She dove back behind the corner too late. Her vision went white, and searing pain went through her right leg. Guns had come out of the hallway walls, and caught her leg as she dove behind the corner. She had taken three bullets to her leg. Something was weird with these bullets, though. They started to cool, rapidly, until they were freezing cold, and extremely painful. They did mostly stop the bleeding, though. She put her hand up to her comm.
"I've been hit. Requesting backup." she said, hissing in pain. Just as she finished her sentence, a blue force field of energy popped up out of nowhere. She touched it, and pulled her hand back quickly. It had burned her hand. It started moving, giving Natasha no choice but to move with it.
"Guys?" she asked.
"There are way too many out here, Widow. We can't get any closer." She cursed under her breath, dragging herself along with the force field. Eventually, she stopped in the middle of a gigantic room. Several scientists surrounded the field, excitedly taking notes. A squad of guards stood nearby, watching her. She stared back at them. She took deep breaths, and assessed her wounds. She was bleeding pretty slowly, but she'd probably pass out in an hour, tops.
"Silly girl. You needed a biometric chip to not activate our security system. I'm surprised you only got three bullets to the leg!" one of the scientists said, sounding ridiculously cheerful. She sent Percy a mental note.
"Can I expect any help from you?" she asked.
"You won't need it, if my hunch is correct." came the vague reply.
She sat there for a while, until she heard a strange noise. She turned to see a hole being cut into the wall with a laser. Bruce Banner kicked the cement loose and walked through the hole, holding a small machine she suspected he had invented and built himself. Several guards shot at him, but he just took cover behind whatever he could find. A couple of guards tried to engage him in hand to hand combat. A punch flew at his face, and he grabbed it, using its momentum to pull it forward and swing the guard around, causing him to stumble into another guard. Natasha stared. "Was that Aikido?" she thought to herself. Another guard kicked at Bruce, and he simply pushed the kick further upwards until the guard fell over. A third tried to tackle the doctor, but he just stepped to the side, and shoved the guard downwards, smashing him into the floor. He took out all of the guards in a similar method.
Then, one of the scientists shot him with an alien weapon, and quickly put a force field around him. Natasha watched with bated breath. The doctor swelled, turned green, and swung around to face her. He didn't roar, or make any sound. He just looked at her curiously. He ran through his barrier like it was made of tissue paper, and entered her little energy circle. He scooped her up, charged at the edge of her barrier, and turned at the last second, wrapping himself around her, and protecting her from the blue energy. He put her down near a computer and quickly decimated the scientists. Natasha took the opportunity to complete her mission. Once she was done, she turned to find the Hulk gazing at her again. He picked her up, put her on his shoulders, and sprinted through the base, going straight through walls. He charged into the ongoing battle against the soldiers, and then, he roared. Everybody turned, surprised. The Hulk smashed the nearest enemy. And Natasha held on as tightly as possible, feeling as if she was riding a bucking bronco. She took out her guns and picked off soldiers from her vantage point.
"Was this your idea?" she asked Percy mentally.
"He did it all on his own. I was expecting him to, though." he replied.
The battle was finished quickly with the Hulk's help. Natasha had left his back a while ago, and was watching him tear things apart with reckless abandon. He punched Thor, smacked Tony away, and roared at Clint. Steve wisely kept his distance. The Hulk looked at Natasha next.
"You know, Bruce looked pretty calm when you interacted with him in the lab. Why don't you try that? " Percy said in her head.
"What? Staring at the Hulk? Or do you mean the hand motion thing? Because I'm already doing the former." she replied, trying not to move as the Hulk focused on her.
"Everything! Trust me on this." Percy responded. She took a deep breath.
"Hey, big guy!" she started, holding a staying hand out to the Hulk, and trying to remember what she had said that day. But her mind was blank.
"Job's finished. It's time to head home." she continued softly. The Hulk roared, but she put her trust in Percy and waited patiently with her hand out, trying to calm her nerves. The concerned chatter of her teammates was distracting her, but she looked at the Hulk, and focused on the fact that somewhere in there, Bruce was watching her. Then, something struck her. The Hulk had brown eyes. Bruce's eyes. She looked deeply into what she knew to be the doctor's eyes as his alter ego looked back, trying to figure out what she was doing. The Hulk averted his gaze, and threw a car at Tony, who was hovering nearby, ready to get her out of there. Suddenly, she remembered what she had said to Bruce.
"The sun's getting real low." she said, and the Hulk padded up to her. His brown eyes looked almost in awe of her, and he reached for her hand slowly. Their hands brushed, just like before. Slowly, she trailed her fingers down his arm, and tapped it at the end. Again, Natasha was caught in Bruce's unyielding brown gaze. And then, the Hulk roared, and staggered away. Tony flew towards her, but the Hulk was shrinking. Green turned to tan skin, forest colored veins faded away, and Bruce was back, lying on the ground and completely winded. Everybody stared in silence. And then, Natasha passed out from blood loss.
Hours later, she blinked her eyes open to find Bruce sitting next to her. Upon seeing her eyes open, he smiled in relief, squeezing her hand briefly.
"Jarvis, please tell everyone that Natasha's awake." he said out loud.
"Certainly, Dr. Banner." Not even a minute later, the other four Avengers rushed into the lab, three of them asking questions about what she had just done, and the fourth congratulating her in a booming voice on taming the Hulk.
"How'd you do that, Nat?"
"Could you do that again? Could she, Bruce?"
"You have done well in taming the green beast, Lady Natasha!"
"Since when could you do that, Red?"
"Does it work consistently, Natasha?"
"If Red's unavailable, can any of the rest of us pull it off, Bruce?"
"STOP THE QUESTIONS AND GIVE NATASHA A CHANCE TO SPEAK." Bruce yelled, and the four Avengers closed their mouths and turned to her.
"What I did was completely done on instinct. There was a phrase I remembered saying when Bruce was the calmest I'd ever seen him. I'd also made a similar hand motion. I took that and ran with it. I don't know whether it would work again. Neither am I sure that you guys could pull it off. It's likely that you'd need to come up with your own version, but I just don't know." Natasha explained tiredly. The Avengers seemed to be satisfied with that. Bruce spoke up.
"I won't allow you to endanger yourself like that." he stated firmly.
"I wasn't- " Bruce interrupted her.
"You could have been hurt badly. I won't risk your life just to make mine a little easier." he continued. Bruce turned and walked out of the room. Natasha swung her legs over the side of the bed, and hopped off. The rest of the Avengers looked rather alarmed at this, but she ignored them, heading down the hallways looking for Bruce. Eventually, she found him in the theater room, watching an old movie. She sat down next to him on the couch. They were silent for a little while before Natasha finally spoke.
"What movie is this?" she asked.
"Roman Holiday. It's basically about a princess and a reporter falling in love in Rome." Bruce replied. They watched the movie in a comfortable silence. Afterwards, Bruce excused himself to go to his bedroom. Natasha followed.
"Is this the elevator?" she said at the doorway, quoting the movie they had just watched.
"This is my room." Bruce said, half continuing the scene, and half earnestly pointing that fact out to her.
"Bruce, I want to talk about earlier today. Just hear me out, okay?" Bruce sighed, but nodded stiffly.
"I noticed that the Hulk's eyes are brown, but your eyes flash green when you turn. Which means that you're always present when the Hulk is in control, right? You might not remember much, but you are somewhere in there. You have to be, because it's true the other way around. The big guy is always present when you are in control, and he gets pulled out under certain circumstances." she continued.
"You're familiar with Pavlov and his dogs, right? Certain behaviors associated with certain stimuli?" Bruce nodded.
"Well, the stimuli in this case would be the little ritual I did when I calmed down the other guy. I think Stark's calling it the lullaby. Regardless of the name, I'll say the phrase, and then do the motion. If we can associate you being calm with the lullaby, then we'll be able to stop the Hulk from rampaging. It will help more than it will hurt. Civillian lives are more important than my own, and I don't want to see you tear yourself apart with guilt." Natasha stated matter of factly. Bruce sighed.
"Just try it?" Natasha asked. He rubbed at his forehead, and gave in.
"Hey, big guy. The sun's getting real low." she said, a hand reached out in front of her. He touched his palm to hers gently, and a tingling sensation ran through her arm. She slowly turned his hand over, and ran her fingers gently down his arm. At the end, she tapped the tips of his fingers. Their eyes locked, green to brown, and Bruce looked relaxed, although his gaze was intense.
"Do you feel calmer?" she questioned.
"Yeah, strangely." he said in a quiet voice.
"If you're going to do this, at least wait for Tony and I to finish the Hulkbuster. I'll stay on comms." Bruce looked at her with imploring eyes.
"Alright, but I noticed that you know Aikido during the battle. The way you redirected all of the attacks coming at you was evidence of that. Where'd you learn it?" Natasha inquired curiously. Bruce looked slightly embarrassed.
"I spent some time in Japan after the accident." he replied. She smiled.
"Good. Aikido's useful. No matter who you're fighting, whether it's a random soldier or even Steve, you can redirect their attacks. You just need to train your reflexes. Of course, we have better than reflexes than others, but they could always improve. So I'm going to train you. Meet me in the gym tomorrow morning at 10." she told him. Bruce looked shocked. She realized that she could sense someone near them, listening in. She excused herself before Bruce had finished processing her words. She turned around the corner, and ran into Percy, who was still disguised as Peter Johnson. "He was the one listening in." she realized.
"So, you're going to train Bruce personally?" her younger brother asked in Russian, actually wiggling his eyebrows. She glared, but Percy kept his trademark troublemaking smirk on his face. She aimed a playful punch at him, but he faded away like the Cheshire Cat, slowly turning into mist with that infuriating smile still in place.
"Just asking!" his voice rang out in her head a second later. She growled curses under her breath.
"Yeah, right. " she thought back. The only response she got back was an amused chuckle. She rolled her eyes and stalked to her room. She had reflex training to plan.