A/N: Sequel to In Sickness and In Health and 'Til Death Do Us Part. Written for Trope Bingo Round Three.

Do Solemnly Swear

The week after Loki took his mind, Clint finds himself watching the footage of Natasha's interrogation over and over and over again until the words are worn smooth from repetition, and he thinks he could say them all by heart.

"Love is for children. I owe him a debt."

He doesn't even notice when the air shifts and his partner finds him. He feels Natasha settle beside him and is not surprised. He plays the tape again, watches the last frame freeze, then plays it again.

She lets him, unspeaking until finally she does speak somewhere in the tenth iteration since she arrived. "Clint."

His hand moves without his thought—a push of the button, the video arrests. He turns to her and presses his forehead to her shoulder. He feels her startled intake of breath, feels her arms come up slowly around him, fingers slowly tangling into his hair.

"You've saved my life a thousand times," he whispers, his own voice rough and alien in his ears. She has repaid that debt again and again and again, with far more repetitions than he has watched her telling Loki that Clint had made another call.

Natasha shudders. She touches his face gently with one finger, tracing the lines of time and circumstance. She pulls him up to look at her and shakes her head. "You promised me. Do you remember?" Her eyes plead with him to remember.

He does not know what she wants from him, and so he is helpless to give it.

"You told me that while you lived, I live," she reminds him. Her hand in his hair has clenched tighter. It hurts, but he doesn't care.

He looks at her puzzled. "Yeah." He pauses, inhales sharply in realization. "I did."

He hadn't meant what she took it to mean. He had promised her protection to come to SHIELD, promised her that it didn't matter what they said, he was going to make sure she survived taking the chance he offered. He had kept that promise, challenging anyone who suggested they finish the mission he'd aborted while she was on base, while she was on probation, if she screwed up her own first mission on behalf of SHIELD. He hadn't realized it was forever.

He had lived as if it was forever.

"Tasha." Clint draws her into his arms as if she is the one who needs comfort. He thinks of bleeding out in Genosha, of her hands grasping his wrists as she gasped her life into his. He thinks of her bite marks on his wrist and the railing in his face. He thinks of her hesitating over the words, 'I've been compromised.'

"I think you made good on that promise."

She shakes her head violently, her shoulders pulling against his embrace.

"I'm alive," Clint tells her softly. He holds her without letting go. "I'm alive."

—

"Regimes fall every day," Natasha had said.

Clint remembered that day in the records room when he met his partner at one of her safehouses SHIELD had never known a thing about. He remembered it when he pointed out that breaking D.C. was more than an incident. He remembered it when he poked fun despite his reeling bitterness at HYDRA and Sitwell and yet another betrayal. He wasn't Russian, but he took comfort anyway as he slept with his head on Natasha's shoulder.

If his world were in the balance, he would barter for the life of one woman. He had promised her when he found her that if the choice ever came between Natasha and SHIELD, he would choose Natasha.

—

"Good to have you back," Maria Hill's voice greeted over the comms.

In some ways, working with the Avengers and Tony Stark was familiar to Clint, like the work he had done for SHIELD for so long. In other ways, it was not. He was rarely paired up with just Natasha. There was no handler, though they did have support, and he couldn't ask for better support than Maria.

"We have guests," Maria added dryly.

"That's nice," Natasha returned in a bored voice. She looked bored too, but Clint knew she was just tired from three days spent gathering intel and confiscating HYDRA equipment under protest.

"Steve and Sam brought in the Winter Soldier."

Clint knew about the Winter Soldier's part in recent events, but more, he knew what the man had once meant to Natasha. He looked over to study his partner, but she merely shot him a smile. There were no flickers of expression he could pinpoint that might be tied to the arrival of her former lover and trainer.

"Good to hear it," she told Maria and started running down her part of the sequence for landing.

Clint returned his focus to bringing them down them safely. Only when they had landed, disembarked, and were removing some of the most dangerous of their weaponry ("No hand-thrown explosives or launchers in the living room," Stark had informed them on arrival; "Pepper's rules.") did he pause to ask her, "Do you remember him?"

Natasha cocked her head at him, slightly puzzled expression on her face, but her fingers didn't stop disarming the launcher in her hands.

"I mean, you know him," Clint clarified, "but do you remember him?"

There was a difference. He did know that Natasha knew what it was like to be unmade. He had seen the layers of her mind like unstable quicksand and experienced firsthand the disorientation of watching her snap from one set of programming to another when she first arrived at SHIELD. Natasha knew her own life now, but not all of her memories were real and not all of her knowledge was memory. They both knew now what it meant to be unmade.

Her expression fell to those little flickers at the edge of a blank mask he had known for so many years now. He wanted to reach out and trace the slight furrow of her brow as she studied him, but he refrained. He wanted to ask her what it felt like to her when Loki had taken his heart but again refrained.

Finally, she sighed as she tossed aside the disabled weapon and stripped off about a third of her guns and blades. "Does it matter?" She didn't even bother looking up when she leaned wearily against him and started walking down the hall.

If it didn't matter to her, it didn't matter to Clint. He shrugged and let her feel the movement in his shoulders as her answer.

—

Natasha slept in his room that night, tangled up in his arms, red hair trailing softly over him when he shifted restlessly, unable to sleep himself. Knots of tension kept Clint up when he knew that sleep would only bring dreams of the tesseract.

He brought his hand up to gently brush the wild strands of red from her cheek. She looked younger in sleep, less like a woman assembled from pieces and forged by strength of will.

"One life, two bodies," he murmured, holding her against him gently, relishing the knowledge that this was his regardless of anything else they did or didn't do about it. He tucked his face against her shoulder and let her scent envelop him as he wrapped her up a little tighter in his embrace.

He would never be separated from her in death, no matter what Loki thought. Clint hadn't told the demigod everything because Loki hadn't asked for an interpretation when Clint said simply, "Kill her and you kill me too." It was a real, physical fact between them, but it was more than that and always had been.

It brought a smile to his face, slightly bitter but wholly satisfied. He would always have Natasha. The knowledge of that finally lulled him to sleep.

—

Natasha has been at SHIELD for three years, the first time she looks at him sideways. Her hand brushes against his arm just so, and Clint stares at her, completely still. She could be a statue, if a warm and inviting one, as unmoving as he is, as if he is skittish and she will scare him away with a touch.

He might be. She could.

Clint stops himself from shuddering and steps away to pick up the mission brief lying on his coffee table. They are scheduled to ship out tomorrow, and she came over for movie night anyway, claiming she wanted to know what happened in the sequel even if he didn't. "I think we're going to have to boil our water." He grins at her.

"Or pack bottled." Natasha rolls her eyes.

He watches her shoulders relax, and then that soft smile she saves for him plays about the edges of her mouth. No hard feelings then.

"What do you think?" he asks, sticking to the subject change. "A thirty-six pack?"

She shoots him a scathing incredulous glare and waves him off. "Never mind. I'll do it. I didn't like that movie." Her tone is surprisingly vicious.

Clint just shrugs. "Told you it sucked. The first one was better. It had Sean Connery as the dragon." The first one was about them.

—

Clint didn't talk about what they were or even admit it in any sideways fashion. Natasha was picky about that sort of thing. If he didn't know any better— Wait a minute. He did know better, and it was absolutely true. Natasha had been paranoid about his safety for the better part of at least three years, though he suspected it had been longer, ever since Genosha and the first time she truly almost lost him. He had only come to realize it in the last year and a half when he connected the dots on why she was so meticulous about her own safety precautions and utterly unwilling to mention their 'condition' to anyone outside of a tiny circle of trust—Clint, herself, Coulson, and Fury.

Which is why he still couldn't figure out why she came herself to deal with him after Loki. Clint didn't talk about that either.

He drummed his fingertips on the conference room table as he waited with Natasha and Pepper for the rest of the Avengers to show up and tried once more to make some sense of it. He wanted to stay alive for the same reason she wanted to stay alive: that was the price of protecting his partner. He hadn't wanted her to risk herself when Loki made him want to…

Her knee brushed his under the table, short circuiting his thoughts.

Clint flicked his gaze to the side to watch her reading through the file on the table in front of her, but she gave no sign of noticing his attention. Her knee stayed put. Natasha had an almost uncanny knack for knowing when he was thinking about New York. He pressed back.

—

The Winter Soldier had a name, James Buchanan Barnes. He asked the other Avengers to call him Bucky.

Clint watched as Natasha established new boundaries with the man. She did not imply the relationship Clint had turned down with her several times, but she did allow the one she had to show. The intimacy they shared after years of sharing lives was palpable between them whenever they took no care to hide it. Natasha didn't just not hide it; she chose small, significant actions to highlight it.

On the few occasions the Avengers would gather together for purely social reasons, Natasha made a point of sitting next to Clint, whether that was at the dinner table or curling up on the couch for a movie or book. She made him coffee and accepted whatever he made for breakfast. That first day Bucky arrived, she slid under his arm and he let her. She was making a point, and even though Bucky seemed to have accepted that point already, Clint doubted she was ready to let down her guard.

He watched as Natasha showed small kindnesses, steering conversations away from the past and from HYDRA at times and removing reminders of what he had been through. She never mentioned Russia or HYDRA or memories rewritten and unwritten, but once, just once, Clint saw Natasha stretch out into an arabesque then stop when Bucky flinched.

—

It is Natasha's first outing after her defection, the first time SHIELD offers her a short leash and lets her walk out of the front doors with Clint. He takes her to his favorite place to get coffee, then takes her out the back and up the side of a tall building to the comfortable perch there where he sits to view the city.

Natasha doesn't speak. It isn't her way. He drinks his coffee and watches the steam pour out of hers until it stops steaming and she finally takes a sip.

It is comfortable, their silence, in the way of those who know each other inside and out, comfortable and worn from familiarity. They are not familiar. He knows next to nothing about her. She knows that he is an archer, and he knows that she was the Black Widow, the most notorious assassin in the world. They don't know each other at all.

"I was never a ballerina," she states abruptly, the first thing out of her mouth after an hour of silence.

He looks at her, studies the pure grace of her body as she stretches without moving from where she sits. Her eyes look up at him under dark lashes.

Her file said she was a ballerina, he remembers vaguely. He remembers reading the file on her and deciding that most of it was wrong. He remembers seeing her for the first person like a shock and knowing that all of it was wrong.

"I know," he says easily. His coffee is gone, but his hands want to do something. They are restless for arrows to fletch or a bow to string. He taps his knees and stares out over the heads that never look up.

He can feel her fury like a heat rising beside him. She thinks it is lack of interest that keeps his eyes scanning outward for threats, for surprises like the shock of seeing her for the first time and seeing a person that had never been allowed the freedom to choose.

She hits his shoulder—hard.

Clint breathes in once, twice, body still. He knows how to be still when he has a target. He turns toward her and gently takes the empty cup from her hand to slot it into his own. "You're not alone any more," he says quietly.

Her brows furrow in confusion. "I don't understand you," she says, and he notes dimly the American accent. Her English is as impeccable as the many faces she can take on.

He looks into her eyes and wonders who it is that stares back at him. She is still a shock to his system to look at. She is like looking at himself.

"I was never a son," he says abruptly. He swings down from his perch with the practiced ease of one who has climbed up and down the building countless times.

After a long moment, she follows.

—

Clint had done this before. It took him weeks to even want to, but he saw the circles darken under Bucky's eyes and saw the signs of nightmares and exhaustion. He knew the hunted look, the wary tension in arms and legs, and the style of hitting formerly Russian operatives seemed to take when they stopped caring whether they were hurting themselves.

Steve was Bucky's best friend and vocally supportive of helping Bucky fit into the team, but Steve hadn't done this before and Bucky was trying very hard to keep that comfortable veneer over the red abyss lurking beneath. Steve was too used to Natasha. He didn't understand that Natasha wasn't whole.

He poured out coffee for Bucky when he got his and Natasha's. He chose to make it the way he had noticed Bucky drinking it instead of the way Natasha said he used to take it, then slid the mug across the counter to rest by Bucky's right hand.

A silent beat. Clint didn't look up. He drained his own mug and refilled it. He kept his eyes on the coffee as he listened to the soft scrape of cup against countertop and saw Natasha's languid posture as she watched Clint from under her lashes. She was studying him, as if trying to see what had motivated the gesture. He heard the imprint of her whisper in his mind, the weight of history, 'I don't understand you.'

She had told Loki one lie in that room. She had told him it wasn't that complicated.

Clint went to wash his mug in the sink and, seeing it was empty, held out a hand for Bucky's.

The soldier handed it over with a wary look in his eyes. "Are you trying to poison me?" he asked.

Clint chuckled dryly as he washed the second cup and dried it. "You have to ask?"

Of course, he didn't. The three of them were trained assassins. They knew how to recognize poison. Clint shrugged and wiped the expression off his face. Neutral tone and neutral body cues meant the words had to be taken on their own. "You aren't alone any more."

He put the mugs in the cupboard and padded out of the kitchen, pausing for less than a heartbeat at Natasha. She smiled at Bucky, then headed out behind him.

—

She slept in his room that night. Clint didn't always know whose ledger drove them into each other, but this time he knew it was the freshly reopened wounds of remembering Loki inside his heart, remembering what it felt like to be unmade. He dreamed of blue light and ballet slippers that were guns in disguise. He dreamed of blood staining blood-red hair and woke with a scream barely swallowed between his lips.

Natasha's arms gripped him tightly enough that he couldn't move, could barely breathe. He stayed in the straitjacket of her embrace until he could look at her and not see blood.

"While I live, you live," she murmured softly, gently. It was too tender to accept.

She rested her head against his shoulder and would not let him pull away. "I'm alive, Clint." The warmth of her voice overwhelmed him. "I'm alive."

—

After New York, she wants to tangle into his arms to sleep. It is their way. They find peace in each other, safety and solace. They are partners.

He cannot.

His heart has been ripped open, bleeding as the god of lies sewed it into a new and different shape. Clint hates that he does not know what he feels, if this desire for Natasha is real or love or lust or battle. He hates that while his mind is his, the things he wants are chaos within him. He hates that he cannot claim the other half of his life, this woman he has poured his soul into.

They have fought back to back. They have fought face to face. They have never fought each other until now.

She whispers Russian endearments and brushes her fingers across his face, but he grips her hand lightly and wraps their fingers together. He sees her frown and knows she does not understand.

"We can't do this," he says, voice heavy with the real meaning behind his words.

She yanks her hand out of his and stalks to the window. They don't talk about this. They don't talk about love and wanting to fall into bed together or even just taste each other's mouth when it's sincere and not a job. They don't talk about the tension thick and heavy between them, ignored year in and out until they could almost choke with the wanting, but Clint will never let them have it. They talk about partnerships and while I live, you live.

"I was never a child," Natasha says, voice furious.

Love is for children, she had told the god of lies. Clint could repeat back every word she said in that room. He knows what she means, that she never had what children had, but she wants it.

But it's a lie. She was a child once, and that is what makes her unmaking so terrible and horrifying. That is what made him make a different call. They stole her from herself. But now it is Clint who has been stolen and he knows they are already compromised, but he cannot bring himself to give her only pieces back.

He lies. He leans back in the bed and forces himself to keep breathing as he answers, "Neither was I."

—

"So you and Natasha." Bucky sounded genuinely curious, neither threatening nor threatened.

Clint replied easily, "We're partners." He kept focused on the knife he was cleaning and watched Bucky do the same.

Bucky laughed, a hollow sound. He stared out over New York from the top of the Avengers Tower, and Clint followed his gaze.

"You love her," the soldier said simply, as if anything about them was simple.

Clint didn't talk about the bond between Natasha and himself, the one that started with a promise to keep her alive and continued with her life to keep him alive. He didn't talk about the fact that there was one solid anchor in his life he couldn't afford to screw up, so refused to.

"That's a conversation you haven't earned," was Clint's only reply.

It silenced them both for a moment. Bucky still felt he knew her so well, and he should. He was there for the Black Widow. He had trained her. He had kept a human core inside of the weapon they had shaped her into. The Winter Soldier had been hers and she had been his.

But he didn't know her. She had left, moved on, tangled herself into an archer physically and emotionally and nearly killed them both by being the one to take that archer down.

"How did she do it?" Bucky asked quietly.

Clint looked up from the knife and heard the desolate version of Natasha's furious 'I was never a child.'

"How did you do it?" Bucky asked.

Clint breathed out and sheathed the knife. He reached for another. "Do what?" There were too many directions the question could go, and if there was one thing Clint had learned quickly from Natasha, it was to keep his options open and never assume he understood what she meant.

A frustrated sound, hesitance, silence, and words stumbling into coherency: "How do I get myself back?"

Perhaps it hadn't been a total lie she'd told him so long ago the night of New York. Natasha had never even asked.

"You can't." Clint had learned that lesson from the broken pieces of his childhood, from the aftermath of his brother's death, from his mentor stabbing his back and Iraqi sands teaching him over and over again that everything could be taken away. Everything. But not Natasha, his mind whispered stubbornly. He shook his head, as much to clear it as to deny Bucky's question. "You have to build something new."

—

He felt weary, like the weight of too many years, too many people he had been, Natasha had been, and now Bucky had been were pressing down on him, crushing him back into the pieces he'd used to build himself again after Loki. The work wasn't done (was it ever?), but he was just so tired of doing it.

Natasha and Steve were laughing in the kitchen at some story Sam was telling. Clint couldn't make himself understand the words. He made coffee and drank it, still listening to the laughter. It added to the heaviness he felt, another set of splinters in the life he couldn't quite hold together.

He had one anchor and he moved to stand next to her, smiling back when she lifted her face to his. She was comfortable here, happy even, but he wasn't Russian. He tended to weep when the world broke into pieces.

He pressed his hand to hers briefly, and he saw the brightness flicker in her eyes. He moved away, let them continue laughing. He went back to the roof and shot arrows into makeshift targets until his fingers bled.

—

They exchange secrets sideways, in little things, unspoken stories that eventually give away everything. Clint tells Natasha that romance can seriously mess up a partnership. He tells her that Mockingbird and Hawkeye were amazing until they weren't, that he'd learned the hard way that relationships tended to go south on a job. She asks him about what happened, and all he can say is, "She made a different call."

He means that Bobbi allowed a man to die because of orders—a man that should have lived.

There have been times Natasha is more direct. She tells him of the Winter Soldier, tells him that warriors can be lovers, that she has only had one partner before Clint and he was her lover. "He trained me as you trained me."

"Pretty sure I didn't teach you how to kill."

She shoots him a scathing glare. "You taught me how to live."

A moment passes. She sits down beside him, so close, studying his face from mere breaths away.

He sees the question in her eyes. He feels her fingers brushing his waist as her eyes ask him to let her kiss him.

Clint tugs her hand to his mouth to brush his lips across her knuckles, but he does not say yes. He is too afraid to say yes.

On the day he felt like he and his brother would work together forever, when he asked Bobbi to marry him on the eve of forever, when he woke in shattered pieces after Loki and saw Natasha and knew it would be him and her and Coulson forever, every single time he lost another person who meant the world. Not Natasha. Not her.

He kisses her hand, but he does not say yes.

—

This is forever with Natasha. He is bleeding out as Natasha drags him through the enemy installation. He is begging her to walk away and live.

"While I live, you live," she tells him. There are flashing lights and a strange metal machine. She wraps her hands around his wrists and whispers, "Hold on. Live."

Alarms wailing, her sharp gasp, and blackness.

—

One life, two bodies. Natasha didn't like to tell anyone what they were to each other—soulmates, partners, two halves of one whole. Clint had no words to explain that she had saved his life with hers, and now they only had one life between them. He had no words, but he had her, and he clung to her as she wrapped herself warmly around him.

It was their way. They were safety and solace, partners.

She didn't always come, but she always seemed to know when he needed her, and she always came when she needed him. Tonight, they both needed. He needed her heat and the solid comfort of her body. He needed an anchor in the quicksand of all the pieces he could never put back together into the Clint Barton before New York, before Loki, before New Mexico, before Bobbi, before Barney. He needed a piece of himself he'd never had to rebuild.

Natasha dreamed.

She started to thrash around midnight, and her hands tightened their grip as she flailed and he called her name, but she couldn't hear him until her hand was on his throat and he pled with her to wake. "Natasha!"

She did. Her eyes snapped open and he saw the tension hold her body rigid. Her gaze cleared of nightmares. She saw him and shuddered as she yanked her hand away.

He rubbed at his throat, but she was pulling away, and it was instinct that made him haul her back into his arms before she could. She needed an anchor, so he gave her one. He tucked her against him and didn't let her go.

He didn't count the time, just waited until endless minutes later, her muscles finally began to relax and her soft sigh warmed his throat.

"We could do this," she murmured softly.

Clint felt his breath catch in the back of his throat. It had been two years since he told her they couldn't, two years and he knew now that his desire for her had nothing to do with Loki.

Time slowed to a crawl as he felt that thick tension choke back upward between them until he had to do something to dispel it, and he laughed short and without humor. "You know I've screwed up every relationship I've ever been in?" Not just the romantic ones, but all of them. But not Natasha, his mind whispered defiantly, stubbornly. Not Natasha.

She pulled her head back to look at him.

He smiled at her just a little and let her hair slide between two of his fingers. He could bury his hands in her hair. He could lose himself in her forever.

"You'd have done it by now," she told him pointedly, a faint hint of that furious heat in her voice from the last time they'd had this conversation.

"Yeah," he answered roughly. He can hardly deny her what his own thoughts had just told him, but he shook his head. "This thing between us,"—he gestured inarticulately, never quite able to name what she had done to save his life—"it's forever. I don't think we can afford to screw it up."

A small, disgusted huff and she rolled over on top of him to lean her arms on his chest and stare down at him in the darkness.

They should turn on a light, he thought. They shouldn't be having this conversation like this, where they could barely see each other, barely read each other except in the lines of their bodies. But he had spent years learning the language of her palm against his chest, her fingers on his arm, her hair trailing as she leaned nearer.

"We won't," she whispered.

This time she didn't ask permission. She kissed him, softly but not chastely. She kissed him, clung to him, and did not let go.

—

Their breath went ragged, and he kissed her like a man in the desert when she was water. He pulled her arms down and her flush against him. He felt like he could not get enough.

But there were questions still nagging at him, one in particular he couldn't accept. She had been compromised, and they both knew it.

Clint pulled her back gently by her arms, and she let him, but barely. Natasha rarely allowed him to control their interactions in a dominant manner. They were partners, equals. It mattered.

"Why did you come after me?" he asked her after a moment of catching his breath.

She stared at him. Her hand went from his shoulder to her hair, and he could see she didn't understand. 'How can you ask that?' her eyes demanded.

He pushed forward, kissed her mouth, her neck, her shoulder, telling her without words to please listen, he had never doubted her. "While you live, I live," he reminded her, hands trailing up her spine and her eyes darkened looking up at him. "You would have let me kill you."

She shook her head, furious light in her eyes. She held him closer, tighter, relaxing only fractionally as he pushed her back by her thighs to keep room for maneuvering.

"You risked it," he persisted.

"Clint—" A sigh, then breath catching as his hand moved upward. "If I couldn't keep you, I didn't want to survive."

She didn't say 'live.'

"Maybe I wanted to die," he admitted with a shudder, and she shuddered with him. He didn't stop touching her, kept moving, pressing, until she gasped. "I knew I had to… I knew we were a packaged deal."

He still couldn't say it.

"We are," Natasha murmured. She held his head in her hands and kissed his forehead, his eyes, his mouth. "We are."

Not were. Not merely physically. We are.

He breathed in the words and pressed his hand against her hip, holding her still. She gripped him tighter and tugged his hair so she could kiss him searingly. He slipped inside her and felt her entire body react.

"I'm alive," she said in a strangled whisper, warm as she embraced him.

"We are," he whispered back.