This work is Pre-Age of Ultron but it DOES contain spoilers. I don't recommend reading before seeing the film.

The beginning of a lullaby, and something else.

The Avengers were drawn together in the wreckage of SHIELD. The instant Natasha uploaded the database; Tony's phone started blowing up with keyword alerts and messages from Pepper and the press. It was Tony that put the call out: Stark Tower is rebuilt and refurnished and open for them to regroup.

It took two months for them to gather together. Natasha was the first through the doors, left homeless and her identity exposed, still reeling from the acquittal from Capitol Hill. She debriefed with Maria, and then Pepper convinced her that the newly named Avengers Tower would be the best place for her. She needed to keep herself known, it couldn't look like she was running or hiding from her past.

Doctor Banner was there, having not really left since Tony moved back from Malibu. He did research in the labs and kept himself calm. He hadn't had an uncontrolled incident in the last 12 months. There were several controlled transformations at Tony's insistence whenever he saw Bruce looking harrowed and more tired than usual. They had gone to the Nevada desert, Tony's old weapons testing ground and punched mountains and ripped up desert bushes. It was on the whole unsatisfying, but it eased the stress for a while. That's also where they began testing for Veronica, creating materials that could hold up under the Hulk's frustration.

Natasha kept to herself in those early weeks, mostly because there was no one to talk to. Clint was in deep cover, no extraction; it was possible he wasn't even aware that he had no SHIELD to report to. Coulson was dead, Fury was pretending to be dead and Steve was staging a hunt for an assassin that didn't want to be found. As for those in the Tower, well...

Tony was still holding onto the grudge of betrayal like he didn't know her job was to spy. It was boring, talking to him. He was too easy to read, his information too public to be interesting. Doctor Banner was a far more interesting case. She observed him working in the research labs, his steady, unchanging breaths, the way he ducked his head whenever he saw her. It was surprisingly easy for her to reconcile this mild-mannered, gentle man with the monster that still disturbed her dreams. She could see the similarities in their face, in Doctor Banner's tightly wound control and even the way his muscles moved. She would be lying if she said the Hulk didn't still terrify her.

Bruce lived with the knowledge that everyone he knew was scared of him. Even Tony, with his careless bravado and insistence that he didn't care, tensed up whenever Bruce told him he was feeling green. He kept his distance from Natasha when he could, but they still ran into each other, sometimes late at night.

Natasha was curled up on the lounge, invisible in the low lights. Bruce didn't notice her. If she stayed silent he would have made his coffee and left without knowledge that a pair of eyes was tracking him. But she spoke, because she couldn't resist the mystery of the good doctor, and people are so much more pliable in the dark of night, more willing to confess and reveal.

"Can't sleep?" she asked.

His eyes darted around until they spotted her, not startled but merely surprised. He shook his head.

"When I sleep, my control is weaker. I can feel him there, under the surface, and it feels like he can overpower me." He gave a slow shrug. "Then again, when I don't sleep, I get irritable and uh, grouchy. It's catch-22. You?"

Natasha pressed her lips together and arched her eyebrow, a little way to say 'Ooh, let's not go there.'

Bruce nodded and looked aside. "I'll leave you be."

"No." Natasha said quickly, she rearranged her legs to indicate a seat next to her. "Stay."

It sounded like an order, so Bruce brought his coffee with him. In the awkward silence that followed, he offered her his coffee silently. Natasha shook her head, and stupidity of the offer made his gut cramp in embarrassment.

Every interaction between the two of them had been fraught with tension, manipulation, accusation, defence. Every word was a powerplay. From Calcutta to the helicarrier to sitting the lounge together, it felt like the only amicable words between them were "we could use a little worse". No, that wasn't quite right. She thought back to a handful of small moments. He looked at her most when he spoke to the team; he followed her with an uneasy, but present, smile. When he put her to the test, and she failed by drawing her gun, he withdrew with an apologetic smile. He had looked disappointed, like he had hoped for a better response, but he talked her down carefully. He said her name gently.

Much of Natasha's work involved manipulating the emotional state of other people. She knew how to make them comfortable and relaxed, aroused and reckless, tense and anxious. Sometimes she could barely see when her own actions were to achieve an end or when they were honest. She knew better than to try and meddle with Bruce's emotions. His control was too important, and when they first met he proved he could just as easily provoke her by using her fears. Still, it was probably wise to put him at ease. Better than the alternative.

She dragged two fingers down her straight hair, stopping where she was thinking about getting it cut. With the movement she relaxed her spine, softened her facial features and stretched out her leg so it just barely grazed Bruce's leg.

Bruce looked startled, even more so than when he first noticed her. Natasha used her most tried and tested method of getting someone to open up and endearing herself to them: she made herself vulnerable.

"There's a whole new world of people shouting for my blood." She says quietly. Bruce leans a little closer to her. She sighed. "And I was just starting to think of myself as a hero."

"You are a hero." Bruce said quickly.

"Not a Superhero." She said pointedly with an arched eyebrow in his direction.

"Super. Yeah." Bruce said sardonically. "That's me to a T, alright. No one should call me a hero."

"Some people do." Natasha remembered the reports, how little boys in Harlem painted their faces green and talked about the big man who stopped the lizard. "Do you?"

"Do I what?"

"Think of yourself as a hero?"

His jaw cocked to the side like he did when he was guarded. "Tony thinks I should. He's got all these crazy ideas about the other guy."

"What does Stark say?"

Bruce leaned forward and placed his coffee on the table. He wrung his hands together, a familiar nervous tick. "He thinks the Hulk saved me. That he exists to keep me safe. Tony thinks the Hulk is, well, not a hero, but a protector."

Natasha nodded slowly. "That makes sense. It's not just when you get angry, right? It's fight or flight."

Bruce looked down at his hands, a bitter expression twisting his features. "Pretty destructive instincts I have, then."

Impulsively, Natasha reached over and took one of his hands between hers. Bruce tensed up, but at least his focus wasn't on self loathing any more. He was confused by her actions. She was usually guarded around him, quietly terrified of the monster he held inside him. Her bravado was half faked. The thing about lying for a living, however, is that the line between truth and deception begins to blur, and if you're not careful, you start to believe the lie.

She laid his arm out on top of hers, palm up and held it still by the elbow. With her free hand she began lightly touching his inner arm and wrist.

Bruce's fist clenched instinctively. "What are you doing?"

"Trying to relax you. Is it working?" She said with a smile.

"Hm, not really." Bruce didn't look comfortable, but he was smiling. Natasha reassessed her goal. She didn't want him exposed, she wanted him smiling.

"What, you trying to find a nerve so you can Vulcan pinch me?" he asked, warily.

"Now wouldn't that be useful to calm the Hulk down." Natasha replied, her fingers still dancing along his skin. "Did you do this a lot in college?"

"Do what?" Bruce asked, not yet smiling.

"Stay up until the early hours of the morning, talk to a pretty girl on your best friend's lounge."

That pulled a surprised laugh from him. "No, no. Uh, pretty girls didn't usually talk to nuclear physics students like me."

Natasha leant her head against the back of the lounge and looked at him. "Their loss."

Maybe it was the intensity of her gaze that caught him off guard, but Bruce gently pulled his arm out from her. A little red tinged the tips of his ears. It was a good look on him.

Her phone gave off an alarm, buzzing urgently. Natasha snatched it up and quickly saw it was a notification from one of her secure communication lines.

"I have to take this." She said.

Bruce stood, picking up his coffee cup with a relaxed wrist. "Duty calls." He said with a smile, standing and nodding his farewell.

"Bruce." Natasha called out. He turned at the doorway. "Thank you for staying."

He smiled again, bashfully.

The message was from Laura Barton. Clint had returned from his mission and went directly to the safe house, as was routine, and was, to quote his wife, freaking the fuck out. Natasha vanished into the night without a goodbye, took undetectable transport to the farmhouse.

Clint was a mess, coming out of deep cover to a world turned upside down. Laura Barton broke the news to him gently, but Clint was furious at himself for being deceived by Hydra, terrified for his family and totally directionless. Natasha helped him work through it by beating each other up until they were both bloody and bruised, then they fell, boneless, on the family lounge. Laura handed out frozen peas to use as ice packs with only a mildly disapproving look and announced she was going to pick up the kids from school.

Clint looked across at Natasha. "How are you holding up?"

"After finding out the only good thing that I ever dedicated my life to was really Hydra, next in a long line of organizations trying to exploit me? Surprisingly well." She reached over and grabbed his hand. "I joined SHIELD because of you, you know. I don't regret that for a moment."

Clint gave her a little smile and squeezed her fingers in return. "So what now?" he asked, leaning forward and putting his head in his hands.

"The team's getting back together." Natasha said. "We're assembling in New York. Are you going to join us?"

"I don't think I'd be welcome." Clint huffed.


"Look, it's one thing to fight alongside people when the world is ending," Clint stood up and started pacing, "but it's a whole other thing to join a team of people that you actively tried to kill."

Natasha played her trump card. "I did. And my brainwashing was far less straightforward than yours." Clint looked chastened, so she continued. "You think the team won't accept you, but you're wrong. Captain America will forgive anyone, and the rest will follow his lead. Will you at least think about it?"

"I will." Clint promised.

"Speaking of brainwashing..." Natasha began, smiling slyly. "Did you know I went toe to toe with the Winter Soldier?"

Clint's mouth dropped open and his eyes went wide. "Again?"

Natasha nodded, more than a little proud. "And you'll never guess his identity."

"You know who he is?"

"One frozen and brainwashed Sergeant James Buchanan Barnes."

Clint went weak at the knees. "No way."

"How about that, Barton? Both your idols are actually the same person."

They were interrupted by the sound of a car pulling up on the gravel.

"You're telling that story over dinner." He said. He lacked the expected intensity because he was wholly captivated by the car doors slamming and his children shouting "Daddy! Daddy!"

He ran out the door to meet them, lifting Cooper off the ground and peppering Lila's face with kisses. "I missed you, I missed you" he repeated over and over again between kisses and hugs. Natasha withdrew into the house to hide in her room long enough for the Barton family to be properly reunited. She was always Lila's favourite, and it was unfair to drag her away from her father too quickly.

She stayed for dinner, telling a version of the demolition of SHIELD that was modified for younger ears over string beans, corn and meatloaf. Natasha genuinely enjoyed spending time with the Bartons. She accepted the offer to stay the night and made herself comfortable in her usual room.

Clint propped himself against the doorframe and folded his arms. "Sorry about the guestroom en suite. The tiles are crooked and the shower leaks in the corner. I'm going to rip it out and start again."

Natasha read between the lines. "Guess that means you're staying."

Clint dropped his head in a nod. "Yeah. I got a lot to do here... It's probably time I settled down."

"I understand."

He rubbed the nape of his neck and looked up at her. "Uhh... Laura and I, we're..." He smiled widely. "We're trying for another baby."

With a big goofy grin on her face, Natasha launched herself at Clint, wrapped her arms around him and squeezed tight. He returned the hug with a low laugh.

Natasha drew back sharply, her serious expression familiar to many of her targets in the field as the last thing they saw before they died. "You're naming her Natasha."

"Aw, c'mon, Nat!" Clint objected.

She punched him. Right in the bruise on his arm. "Don't fight me on this, Clint."

Natasha returned to New York empty-handed. If anyone noticed she was quieter than usual, they didn't comment on it. Bruce might have sent her a few concerned looks, but it was overlooked in the commotion that followed when Thor flew in. Flew in the typical sense. In civilian clothes, with his bags packed and his big frame squashed into economy seats.

"You couldn't upgrade him to Business Class at least?" Bruce asked.

Tony hushed him. "He doesn't know there's an alternative." He stage whispered behind his hand.

"You humans are tiny and your transportation systems are inconvenient." Thor declared upon landing in JFK airport. The only reason he wasn't grouchier was because Jane had sat next to him, lifted the armrest separating them and spent the entire 9 hour flight from London cuddling so he had a little extra room.

"Did your flight really get delayed by a thunderstorm?" Tony asked, popping the trunk of his car to let Thor load in his and Jane's luggage. "That's embarrassing."

"Well then, you can conduct lightening while encased in a metal tube next time." Thor smiled, holding out a bag to Tony. "See how you like it."

Tony took the bag from him, and the instant Thor let go of the handles, the bag fell to the ground with a dull thunk. Tony groaned trying to lift it and Thor doubled over in hearty laughter. Eventually he took pity and unzipped the bag and lifted out Mjölnir. Thor grinned at Tony.

"Ha, ha." Tony said sarcastically. "Laugh it up, big guy. I'm reporting you to TSA. There's no way you got through security with this thing."

With the return of Thor to New York, the mission of the team became clear. The leaked Hydra files revealed the Chitauri sceptre found its way into Hydra's possession, property of one Baron Wolfgang Von Strucker. The new intel, and Thor's insistence, was what drew Steve Rogers away from his search for Bucky Barnes. He left Sam Wilson in charge of the missing person's.

Natasha sent a message to Clint: We have a mission: We're going after Loki's sceptre.

His reply was quick: I'm coming with you.

Clint arrived within a day, before Steve even travelled from whatever corner of the earth where they tracked the Winter Soldier. Natasha stayed close to him, their shoulders occasionally brushing. Bruce watched them from a distance.

Captain Rogers was the last one on the team through the doors. The moment he entered, something clicked into place. They had a mission now, they had purpose again.

"You're the Cap, Cap" Tony gestured towards the hologram indicating all known Hydra bases.

Tony often did that, made a vocal announcement of his acceptance of Steve's authority. It didn't escape Natasha's notice that Steve would also look to Tony before giving orders. She hadn't yet figured out if it was because he was checking the compliance of the most unpredictable member of the team, their conflicting personalities or insecurity in his role as leader, but it seemed to accomplish the goal.

But Steve in leadership was Steve in his element. He was a tactical genius, not only in military strategies but also in understanding his team, organizing them into the best force they could be. And the Avengers were formidable.

On their first mission to find the sceptre, they attacked a heavily defended Hydra base in the Caucasus Mountains. Once the Avengers hit and chaos reigned, Black Widow escorted Doctor Banner into the labs. Captain America had ordered them to collect all information they could about the illegal experimentation from the database. Natasha knew why. He hoped it would lead to Bucky.

Unfortunately, what they found got Bruce angry. They were experimenting on children. Toddlers. Their lives were reduced to a single identification number and a few data points.

"Banner. Doctor Banner." Natasha's voice was sharp. "You have to leave. Now."

Bruce's fist uncurled from the dent in the table and he stumbled away from the computer. Natasha threw an arm around his shoulders and led him outside. "Captain." She radioed. "We have a green situation here. We're going for some fresh air."

Her casual phrasing was betrayed by the way she shot off the lock on the door from 10 feet away and burst through it. She threw Bruce into the snow bank so the cold could shock his system back to the present, but it was too late.

His combat fatigues ripped apart as his muscles bulged stretched. Natasha could see green spreading down his fingers as they cramped in the snow.

"Okay, I'm going to leave you be." She said as she took off running. She'd barely gotten a hundred yards before a roar echoed through the icy forest. She had dressed for the terrain and infiltration, wearing an all white version of her uniform so she could disappear into the snow storm. She wedged herself into a crack in the rocks and not a moment later a streak of green barrelled past her hiding place.

"Jolly Green's come out to play." Stark reported.

"Well can someone find him something to do?" Captain Rogers said.

"Two tanks have slipped the perimeter, escaping via Eastern Road." Said Hawkeye.

"Someone else is gonna have to set up those piñata's." Stark huffed, the roar of explosion coming from his end of the radio.

Natasha took a deep breath and launched herself out of the crevasse. "I'm on it."

"Nat, you sure?" Hawkeye's concern was evident in his voice.

"Yeah. It'll be fun." She replied. "Exposure therapy, right?"

By swinging around trees and darting quickly back and forth, she was able to shepherd the Hulk onto the East road and let him run through the heavily armoured vehicles. Now they had a common enemy, she could trust the Hulk to be focused on the goal of tearing the metal apart. It was easier to be near the Hulk in the open space of the forest. The last time she was close quarters with him was in the claustrophobic helicarrier. At least here she had the freedom to run around and attack from a different angle if he was getting too close.

One of the vehicles made it past their blockade. Natasha lifted up one of the fallen motorbikes and made chase. The Hulk ran along beside her.

The Hydra scientists made it a few miles away from base before they were destroyed by the duo. Between the blunt weapon and the fine instrument they had no hope of escape. In the fight, Natasha was distracted working so close to the Hulk and one of the soldiers got lucky. He slashed her across the thigh, leaving a deep wound gushing blood across her white uniform. She took him down with a vengeance.

The Hulk destroyed the vehicle and none of the Hydra workers were moving. Natasha slumped at the base of a tree and grabbed a handful of icy snow. She pressed the snow against her wound and it instantly stained red. She gasped quietly and shut her eyes against the pain.

When she opened them again, the Hulk was looming over her.

"Shit." She breathed.

He looked at her, perplexed, then backed off and started pacing. She was distinctly reminded of how predators behave when confronted by prey that doesn't run – confused, unsure. Predatory instincts are hard coded to follow familiar patterns; they don't have instructions for when prey doesn't behave like prey. With that in mind she let a confident mask cover her face, lifted her chin and spoke easily.

"Hey big guy."

He turned to her sharply. She was unflinching.

"I don't want to rush you, but..." she glanced over at the sun setting behind a mountain. "Sun's getting real low. It's going to drop below freezing temps in half an hour and Banner isn't-"

The Hulk got angry.

"Okay." Natasha said quickly. "We'll scratch him off our conversation starters list. Either way, I'm not going to last long in the cold. I'm bleeding out here." Her head thumped against the bark. "A doctor would be great right about now."

The Hulk looked just placid enough to ignore her. She was just about to radio for help when he crouched down in front of her and sniffed, his huge nostrils flaring.

A large green hand reached out to her wounded leg.

She lifted her hand – stop – and he paused, head cocked to the side. His hand moved trajectory, instead drawn to her wet, red hand. Natasha stopped breathing. Three thick, green fingers pressed against the centre of her palm. They slid upwards and curled around her fingers, enclosing her hand in his large fist.

He drew back, inspecting his hand carefully. He sat down with a thump and the ground shook. With his hands in his lap he looked like a child but he was touching sticky blood between his fingers. He started blinking rapidly like he'd been hit with one of Hawkeye's tranq arrows.

The Hulk shuddered, slumping over to one side as he shrank. He writhed in the snow as his skin changed colour and his body shrank. He fell, face down into the snow and a little puddle formed around him, his overheated skin melting the snow.

Bruce's head rolled so he could meet her astonished gaze. "Natasha?" He asked, voice hoarse. He finally saw the pool of blood surrounding her. "Fuck." He sat up, tugging off the tattered pants hanging loose around his hips.

"Buy me a drink first." She smiled weakly.

Seemingly uncaring about the cold or his nakedness, Bruce knelt in the snow to attend to her cut. He wrapped the strips of his pants around her thigh, binding her wound tightly, even as blood seeped through the material.

"I didn't know you could transform back like that." Natasha said.

Bruce furrowed his brow. "Neither did I."

He packed some snow between the final layers of the make-shift bandaged and tied it off. Then he hesitated, hands hovering over her wounded thigh.

He was a sight to behold. A naked man crouched in the snow, warm to the touch. A healer whose gentle hands just ripped a tank in half. She couldn't stop herself from looking at him; he was too beautiful to look away.

"I'm sorry." He said, head still hanging down. "I shouldn't have lost control like that."

"No, I understand." Natasha replied. "Human experimentation, especially kids, it's a sore spot. It should be for everyone. Frankly I'd be more concerned if you didn't get explosively angry."

He looked up at her, lips lopsidedly parted and halfway to a smile. And suddenly it was too much, she looked away and radioed in their position and the need for medical attention.

"And some pants for Doctor Banner." She added, nudging his bare thigh with her good leg. The good doctor finally had the sense to feel embarrassed and cover himself with his hands.

The quinjet landed up alongside the remains of the Hydra tanks and Hawkeye jumped out. He tossed a pair of pants at Bruce without looking, his focus completely on Natasha.

"Did he get you?" Clint asked quietly, inclining his head ever so slightly in Bruce's direction.

Natasha shook her head. "Just a lucky shot from a soldier. I'm fine."

The Iron Man armour landed beside Bruce and Tony flicked up his faceplate. "And here I was thinking I'd get to wrestle Jolly Green." He said with a sigh, like he was actually looking forward to the idea.

"Don't get too excited." Bruce said, standing up. He wrapped his arms around his chest, finally feeling the cold wind. "I was able to get control again."

Tony pulled a face. "How?"

Bruce seemed at a loss for words. Natasha spoke for him. "Misdirection and confusion."

"You hearing this, Rogers?" Tony said into the radio as Clint helped Natasha into the quinjet and Bruce stumbled after them, a hand on the back of Tony's armour. "Apparently Widow can sing a pretty song and make the Hulk go away."

"At least that's some good news." Steve replied. "Thor says there's no sign of the sceptre here."

The Captain ran up to the quinjet, having already cleared the area of Hydra agents. Thor landed with a thud and walked on board after him. Natasha lay down carefully.

"Indeed." Thor intoned. "I do not believe the sceptre was ever at this location."

"Did you find-?" Steve began. Natasha cut him off.

"There are no files in there that we want anything to do with."

Bruce swallowed thickly, pulling a blanket around his shoulders. Steve looked at Tony who nodded and slammed his faceplate down.

"Permission to blow this joint, Captain?" The metallic voice asked.

"Blow it up." Steve replied with a smirk.

Tony flew out of the quinjet before Clint sat at the controls, closed the doors and lifted them into the air. Flying circles around them, Iron Man escorted the Avengers to a safe distance, turned around to face the Hydra base and fired a missile right into the heart of it.

The explosion could be heard within the quinjet. Natasha closed her eyes, comfortable listening to the sounds of her teammates talking about the fight and their next target.

"One down." She said with a smile.