A/N: Well, shit...so yeah, this happened. My brain latched onto another errant bit of thought and turned it into another 'What If' scenario. This is just going to be a one-shot, though. Perhaps someday, I might decide to keep playing and see where this one little change takes us, but for now, this is as far as this idea is going.

Warnings: If you haven't at the very least read up to Chapter 20 of The Ghost, this O/S will likely make very little sense. Additionally, some parts will seem very familiar as sections are lifted directly from Ch. 20. 

Also, you know, spoilers abound. You have been warned. 

And if you haven't read The Ghost, well, I highly recommend it. ;)

Same disclaimers as always apply: I only own my Original Characters and Scenarios. If it's recognizable beyond that, it's probably not mine. 

***

Somewhere over the Atlantic

Spring 2015

"You know, I've heard of teen moms going on to become CEOs or star in bad TV shows; never heard of one going all Assassin's Creed, before."

Natasha made an annoyed sound deep in her throat as Nadine glared at Stark. Really, the man was incorrigible, and it was wearing on Nadine's patience. "That's enough, Tony. I think you've made your point," the redhead said wryly, though there was no missing the pointed warning in her voice.

Her sister's too, evidently.

Stark looked to his teammate, his eyes wide and incredulous. But there was a subtle, hard wariness just below the surface that hinted at why it was very unwise to dismiss Tony Stark as merely irreverent and immature.

"What?! You of all people don't want to know more? You, the super spy? The one she was hired to kill not all that long ago?" Natasha casually resumed her seat next to Nadine, leaning back with a careless shrug as she glanced innocently up at Stark.

"Blackmailed, not hired, Tony. That's an important distinction, thank you. And I know everything I need to know about her already," she said dismissively, nearly causing Nadine to smirk at the baffled look that was startled onto Stark's face. "I probably know more about her than any of you ever will. Not that I'm likely to tell you, no matter how nicely you ask." She looked pointedly at Stark, a sweet smile on her face.

"How?" Banner asked, genuinely curious even as Tony gasped dramatically, before bursting out with a sarcastic—and even mildly petulant— "she's not sharing! No fair!" For the most part everyone ignored him, though Banner did roll his eyes at the billionaire's childish antics. Natasha just smiled slyly, though her eyes didn't hold the usual playful twinkle baiting Tony usually inspired. Hawkeye, seeing the grin, only groaned, looking like the obvious had been right in front of him without realizing it until it reached up and slapped him in the face.

"She was part of the KGB program that trained you, wasn't she: The Black Widow Program." Her smile dimming minutely, Natasha nodded once in confirmation. Nadine merely let her head fall back against the headrest behind her, letting her eyes slide up to stare at the ceiling as Natasha elaborated at her team's—not counting Stark—unspoken urging to elaborate.

"If she hadn't run and disappeared from the program, it's fair to say she might have earned the Black Widow designation instead of me." Nadine chuckled bitterly at the assertion, dropping her eyes to glance at her little sister.

"Not likely," she contradicted lightly, "I never would have made it to Graduation if not for the success of the Treatments; I was a little too strong-willed for their tastes." Natasha raised an amused eyebrow.

"And I wasn't?" Nadine chuckled again, almost genuinely this time.

"That is true; you were too. But you played the game better. I was good at killing, the best, even—still am—but had I not run, they would have had to eliminate me within two years, three most. I had no interest in playing along with what they told me to do," she trailed off, only to scoff. "Either that or they would've taken a page out of the Winter Soldier playbook and just outright wiped me."

The Quinjet went abruptly and profoundly quiet.

Nadine frowned, suddenly on edge as she glanced to each of the Avengers in turn. While for the most part they simply looked troubled, glancing to each other with wary looks, it was the reactions of two in particular that caught Nadine's attention.

Especially given how everyone else was looking to the Captain.

Natasha was visibly worried, her gaze veiled as she studied Rogers. While Rogers? A distinct knot of unease formed in Nadine's gut at the suddenly unreadable expression on his face as his ocean-hued eyes fixed unerringly on Nadine and the anxious tension written in every line of his body.

"What do you mean? What do you know about the Winter Soldier?"

Nadine blinked at the decidedly interrogatory tone of his questions. She suppressed the urge to shift uneasily. Her frown deepened as she glanced to Natasha. Natasha's lips pursed.

"Steve, I already told you," the redheaded spy broke in softly, her voice firm. "He was brought in during my—our," she gestured absently toward Nadine, "training to work with us on hand-to-hand." Frustration flickered in the Captain's eyes and he shot his teammate a sharp look.

"I know, Nat." He looked back to Nadine. "But I want to hear what she knows."

"Now's not really the time—"

"We're not due to arrive for a few hours yet," Rogers countered, the impatience colouring his tone far more pronounced. Natasha made a frustrated sound of her own.

"And you're going to be able to focus properly once we get there if you go down this road right now?" Natasha said pointedly. Rogers very nearly scowled. Nadine watched the two of them with just as much interest as the rest of the team, feeling like she was missing something. She didn't like the feeling—it left her feeling particularly defensive.

And considering why the Winter Soldier was of particular interest to Nadine?

Defensive was far from ideal.

"No worse than if I'm left wondering what she might know that could help find him." Nadine's eyes narrowed, something snapping in her.

"Why, so you can finish your grudge match from DC?"

"Nadya!" The Captain bristled even as Natasha admonished the blonde assassin, her tone thickly laced with shock and warning. Nadine's features grew cool as she turned to her long-ago little sister.

"Well," she prompted, preternaturally calm, "why else would he be asking? After what happened in DC? Him and the Winter Soldier all but destroying a crowded city street in broad daylight?" She ignored the way her stomach flipped at the memory of finding Nina watching the footage of that fight online, utterly fascinated while Nadine had only felt sick.

Well, the feeling had more than returned.

They were getting far too close to territory Nadine desperately wanted to stay away from.

She was starting to feel dangerously irrational.

"This Winter Soldier," Thor mused then, his brows pinching thoughtfully, interrupting the quickly escalating tension between the Captain and the assassin. He looked to Rogers. "You told me of him. He was your friend, once, was he not? His mind altered by means not dissimilar from the effects of Loki's Sceptre?"

Every drop of blood drained from Nadine's face.

"What?" The word was soft, broken and more a breathless gasp than an exclamation.

"Oh yeah," Stark broke in then, his irreverent tone contradicting the sharp, almost angry expression he wore as he briskly flicked his phone once more, projecting a new set of images accompanied by a name in bold capital letters above a rendition of a military service record to hover in the air between Nadine and the Captain. "He and the Soldier go way back." But his poorly hidden temper on his friend's behalf was entirely lost on Nadine.

She couldn't tear her attention away from the projection.

James Buchanan 'Bucky' Barnes

Nadine didn't hear both Barton and Banner's warning to Stark to stay out of it. She didn't even realize she'd stood, her suddenly shaking legs nearly giving way.

For all that the picture staring back at her was of a young man in a World War II uniform with charming grin instead of the broken and brutal assassin she'd known, there was no mistaking who he was.

She finally knew his name.

Nor was there any mistaking the man laughing beside him in what was unmistakably footage from an old war reel.

Her gaze snapped to the Captain.

Rogers' jaw clenched, straightening. But after a moment, he nodded sharply in confirmation.

Nadine felt suddenly light-headed. "That's...that's not possible..." Of all the things she could've imagined, that was the last thing she'd expected to hear. She looked helplessly between him and her sister, searching desperately for confirmation.

Sympathy bright in her sister's eyes, Natasha nodded slowly. "Nadya—" Nadine flinched away on pure instinct from Natasha's outstretched hand.

Her gaze was drawn back to the image as though drawn by magnet.

"Bucky was my best friend growing up. He always had my back and I his. He was even one of my Commandoes during the War," Rogers said, his voice tight and low.

Slowly, Nadine's head began to shake, only to stop abruptly as her thoughts started to shake free of her shock.

"Cryo," she murmured thoughtfully. "They've been freezing him. That's the only explanation..."

"That's our guess, too." She looked up at Rogers' agreement. Her chest suddenly felt tight.

"You want to help him," she said softly then. It wasn't a question. He met her eye. Nadine fought against the way her breath caught in her chest at the almost desperate shadow lingering behind the determination that stared back at her.

"He would for me."

A single rasping word echoed unbidden in her ears. Go.

"He let me go." Rogers frowned in confusion, but Natasha's startled gaze snapped to Nadine.

But no one was more surprised than Nadine.

"What do you mean," Natasha asked sharply. Nadine inhaled a slow, bracing breath, suddenly struggling to maintain her composure.

She was walking a fine line.

The knots in her stomach twisted tighter.

"The night I...I ran. He caught me. He should've killed me, but..." she faltered, struggling to keep her voice level. She lifted her chin. "He didn't. Instead he broke through his programming long enough to let me go." Rogers' eyes widened in surprise as Natasha looked to Nadine, equally started even if she hid it better.

"Wait, I thought that programming was damned near impossible to break," Clint said then. It was a sharp reminder that they had an audience. Immediately, Nadine's impasive mask snapped into place. "Cap, he nearly killed you before you were able to get through to him and the two of you were practically brothers." Something in Nadine's gut clenched.

"His programming was beginning to weaken by the time I ran, but his handlers didn't want to risk damaging him by putting him through more memory-modifications than they had to." The brisk explanation spilled out before Nadine had even consciously decided whether or not to share them. "I don't think they realized just how much he was starting to fight it."

"Did you know that?" Nadine was suddenly furious with herself at Rogers's question to her sister. Natasha spared her a brief glance, her expression carefully unreadable. Apparently it was answer enough. Rogers turned his narrowing gaze to Nadine.

"How would you know that?" Nadine levelly met his eye. The deflection was out of her mouth on pure instinct.

Old habits die hard, and all.

"I was several years older than Natasha when he was brought in," Nadine pointed out dryly. Reluctantly, Rogers seemed to accept the explanation when she didn't offer anything further.

Her stomach flipped uncomfortably with something that felt oddly like guilt.

Like brothers, Barton had said.

It didn't take long to determine why; the feeling worsened as Rogers considered her, a gleam in his eyes that she could only describe as the first tentative stirrings of hope. Her chest suddenly felt tight.

His best friend.

She found herself glancing to Natasha. Her sister was already watching her, her green eyes unsettlingly knowing.

Nadine suddenly felt sick.

"I've been looking for him." The confession spilled out. She forced herself to look to the Captain. His eyes had blown wide, his lips parting. Nadine could feel Natasha's concerned gaze boring into her. The knots in her stomach quivered.

Never had she felt so conflicted.

"Why?" She dropped Rogers' gaze, her head turning toward Banner at his question.

But she couldn't quite bear to look at anyone.

Nor could she bring herself to simply say why.

Her throat closed up.

O Bozhe, was she really considering spilling the secrets she'd fought and killed to protect for the last eighteen years?

"It's because he let you go, isn't it," Rogers finally said when it became clear she wasn't about to answer. "You feel like you owe him."

If only he knew...

Nadine's stomach churned with guilt and shame, the long-familiar emotions suddenly feeling keen and fresh. She had to force herself not to react, to keep breathing normally as though his statement hadn't felt like a punch to the gut.

Practically brothers...

Just like Natasha was practically her sister. It made him...

...Family.

It changed nothing, a virulent, desperate part of her hissed.

It changed everything, whispered another.

That she was even considering telling him why had her long-ingrained instincts rebelling. Viciously. She felt like a plucked string pulled far too tight.

"He gave me...he gave me everything," she said softly then, her voice wavering. She bristled internally at sounding so pathetic. But neither could she bring herself to reveal anything more.

Some habits were just too deeply ingrained.

This time, she didn't flinch when Natasha's hand brushed against her arm.

"It's okay, Nadya," she said softly. "Anything else can wait until after we've retrieved the Sceptre and get Nina back." Nadine only barely restrained the shuddering breath that tried to escape. Natasha's meaning was clear.

Her sister knew she'd reached her limit.

She'd shared enough.

Something in Nadine's twisting gut eased and she sank back into her seat, the tension flooding the Quinjet finally started to lessen.

"Speaking of your kid, why did Strucker kidnap her?"

Until Stark opened his mouth. Nadine instinctively bristled.

"Is the reason really that important?" She countered coolly, fixing him with an icy stare. The billionaire raised a challenging brow at her.

"Oh, I don't know. That answer right there kind of makes me think it is."

"Tony," Rogers warned. But Stark just met his warning with a defiant glance.

"What, you don't think the 'why's of Madam Ghost's mini-me ending up in the HYDRA's Lair is relevant? 'Cause that seems kinda relevant to me."

"It's pretty obvious, isn't it?" Nadine stiffened as Barton piped up. The archer shrugged at the questioning—and guarded where the pair of sister spies was concerned—looks that turned his way. "Her Mom's The Ghost—one of the most elite assassins in the world. Leverage, blackmail, revenge. Take your pick."

But before Nadine could so much as breathe a silent sigh of relief, Stark made and unconvinced sound, his hand wiggling in the accompanying gesture. "Plausible. Still seems a bold move for him, though. Not quite S.O.P. for a shadow-y sort of mad scientist." He gestured flippantly at Nadine. "'til now."

"Strucker's focus is weapons research and development, not plots or pulling strings," Dr. Banner said with a thoughtful frown. "Our intel says he's focused on Enhancements, super soldiers, weapons tech, even some robotics; that sort of thing."

"Because a head of HYDRA can't have his fingers in a bunch of different pies," Clint pointed out dryly. "Especially since most of the other heads have been lopped off."

"Are we certain Strucker wasn't after the girl herself? Was one of the crimes your governments wished to apprehend him for not human experimentation?" Nadine froze at Thor's suggestion, suddenly feeling cold, the burn of bile clawing at her throat.

She wasn't ready for this...

Even try as she might to deny it to herself, even though part of her already knew it was no longer anything but inevitable, the prospect of her secrets being laid bare—before complete strangers at that—filled her with nothing but dread and despair.

"What, you mean not as a hostage? As a, what...a test subject?" Banner said, looking to the Asgardian.

"Or research subject." Stark mused thoughtfully. His teammates looked to him, varying degrees of confusion and consideration crossing their faces. "Could Ms. Almost-Black Widow have a little something extra going for her? Or maybe Daddy-Dearest does?"

Nadine was very careful to levelly meet the Stark's searching gaze, her impassive mask securely in place. It was none of Stark's business.

And she had finally lost what was left of her patience.

Rational or not, Nadine's long-ingrained mask crystalized and her voice hardened accordingly.

"Strucker," she said icily, "currently has my daughter. I ask again: does the reason why matter?" Stark was visibly taken aback at the abrupt shift in her tone.

"It doesn't," Natasha interjected firmly, glaring at Stark. "Tony just doesn't like puzzles he can't solve."

"Dismissive, much," Stark quipped indignantly back. And once more the image of Nadine and Nina was brought up, replacing Barnes. Nadine bristled, feeling herself go cold as The Ghost in her began to stir. "I think I'd call the last Head of HYDRA going to the effort of trying to stroke off The Ghost just to get to one teenager more than just a puzzle."

"His smile..."

If the Quinjet had gone quiet before, it was deathly silent now.

The blood in Nadine's veins turned to ice.

Rogers was staring, eyes wide, his features caught in a painful mix of awe and disbelief, at the image. Staring at Nina. Nadine's chest ached, the ice splintering into shards that cut her to the bone. She couldn't breathe.

She could see him putting the pieces together.

Stark frowned, bewildered, at his teammate's awestruck murmur and stunned expression. "Care to fill us in, Cap?" Rogers blinked, startled. He spared a quick glance at Stark before his gaze slid slowly to Nadine.

His unspoken question was clear in his eyes.

Nadine's mask started to crumble, a damp, traitorous prickle beginning to form behind her eyes.

Her lips formed a single, silent word: please.

"That's why, isn't it." It was undoubtedly a statement, but Nadine heard all the implied questions regardless.

That's why you want to find Bucky?

That's why you know so much about him?

That's why you ran?

That's why Strucker wanted her?

That's why you refuse to answer Tony's question?

That's why you won't answer about her father?

Because he's her father.

Her voice little more than a whisper, her answer to them all and more was a single word.

"Yes."

Rogers' eyes slid shut, his arms crossing tight across his chest, one hand lifting to cover his thin-lipped mouth. A despondent sob caught painfully in Nadine's throat.

She had failed.

No, not just failed...

She had betrayed everything she'd fought so hard to protect: her past...her secrets...

...Nina.

"Would someone care to explain what all this is about?" Stark broke in irritably, gesturing loudly between Rogers, Nadine and even a carefully blank-faced Natasha.

"Steve has figured something out," Thor said carefully, glancing shrewdly between the two sister spies and the Captain. Stark shot the Asgardian a look of deep aggravation.

"Thank you, Captain O," he snarked. Thor frowned at the billionaire, vaguely confused at the reference.

"Cap?" Barton asked carefully, standing from his own seat to stand next to Natasha, concern etched deeply into his features even as a calculating light flickered briefly in his eyes as he glanced between the two spies, Rogers and the image of Nina much as Thor had.

Nadine stiffened as Rogers straightened, seeming to brush off just how much the revelation had gotten to him. He stared at Nadine for a long moment. Panic began to tremor painfully in the centre of her chest.

His features tightened for a split-second before they cleared.

And he turned to Stark.

"Ryker's Enhanced." Nadine nearly choked at the bald-faced lie. "And she passed it on to her daughter." Stark didn't look convinced, his eyes narrowing as he studied the Captain.

Rogers just stared right back.

"Treatments." It was Barton's memory that finally broke the budding stare-down between Rogers and Stark. The billionaire looking curiously to his teammate. Out of the corner of her eye, Nadine saw the archer look to her. "You said something earlier about 'treatments'."

"It was an Enhancement initiative," Natasha explained softly after a long, tense moment. "A trial program that was run where we were trained. The older girls were subjects, including Nadine. She was one of the few survivors and, best I've been able to tell, the only one they worked on." Nadine shot a quick glance to her sister, the cold defensiveness of the moment before beginning to melt away.

It wasn't hard to figure out what she was doing, and Nadine was grateful.

This was safer territory.

Natasha's lip quirked in the faintest of sympathetic grins.

"And the effects?"

Natasha hesitated at Banner's question, her lips thinning as she considered how best to explain what painfully little she knew.

"Some physiological improvements," Nadine broke in dully, "enhanced reflexes, speed and strength; accelerated healing; increased stamina; greater pain tolerance; improved and increased metabolism." Stark made a vindicated sound that Nadine pointedly ignored. "They..." she hesitated, wary of the reaction she suspected Rogers would have, "they were looking to make a...better version of...of Barnes." She silently berated herself not just for the stumble, but for the unexpected way her throat suddenly threatened to close off. Natasha frowned, concern flickering with sympathy in her familiar green gaze.

"And Nina," Banner piped up then, the scientist in him fascinated.

Nadine considered for a moment before sighing. "It's difficult to say," she finally admitted, not seeing the harm in sharing. "Slightly above average speed and strength, perhaps a slightly elevated healing factor and metabolism. I wouldn't call it enough to qualify as actual Enhancement, though."

"Even if Strucker knows that?" Barton was quick to point out. "It goes a long way toward explaining why Strucker would want your kid." Nadine could only nod stiffly.

"So why not just say so?" Banner asked tentatively then, honestly confused.

"A lifetime of habit," Nadine said, her voice embarrassingly hollow. "Nina was kidnapped because someone found out the secret I've spent most of the past eighteen years doing everything I could to bury, all to protect my child from people like Strucker." Banner winced, instantly apologetic.

"The way we were raised? The lives we've had?" Natasha added softly, looking sadly to Banner. "Secrets are literally life and death." She looked pointedly to Rogers then, her vibrant green eyes at once sympathetic and unapologetic. "Even among allies."

Rogers let out a heavy sigh, but his chin dipped minutely, acknowledging Nat's implied point.

After a long moment, he drew in a deep, slow breath, visibly steeling himself. The Captain looked around to the rest of his team, fixing them each with a steady look. Nadine included. "Suffice to say, it seems pretty clear Ryker has some good reasons for not sharing." He glanced to Stark, nodding up to the image of Nina and Nadine. "You can put that away now." Though decidedly disgruntled, Stark complied. "If she wants to share more later, that's her call. But we've got a mission to complete first; find the Sceptre, take down Strucker and find Ryker's daughter. Those are our priorities."

Nadine nearly could've cried for relief.

He was willing to wait for the rest of his answers.

And much to Nadine's shock, he turned to her then. "You still with us?"

Her expression carefully schooled to betray nothing of the emotional wreck she was inside, Nadine looked assessingly around to the rest of the Avengers, meeting Natasha's calculating gaze for a long moment, before finally turning back to Rogers.

In the end, it was a startlingly easy answer to give.

Her composure once more—tentatively—in hand, Nadine nodded briskly.

His nod in return was equally brisk. "Good." Only for the corner of his mouth to twitch. Nadine didn't expect him to take a step toward her, holding out his hand.

But much to her own surprise, she only hesitated for a moment before taking it. Rogers grinned.

Not that the satisfied relief in his expression entirely hid the trace of caution that lingered behind it. Nadine was nearly tempted to grin—he was no pushover, that was for sure.

"Welcome to the team," he said with an assured sort of finality. Nadine's eyes narrowed, resisting the temptation to scowl.

"I'm not an Avenger."

"Maybe not yet," Barton piped up cheekily behind her, "but it'll happen. We have a habit of adopting strays." Natasha scoffed, fixing the archer with an admonishing glare. Not that it entirely hid the amused grin playing about her mouth.

Nodding briskly as he dropped her hand, Rogers fixed Barton with a lightly reprimanding glance of his own. "Mission first. Then we can work on the recruitment pitch." Barton chuckled lightly.

And Nadine was suddenly wondering what she'd just gotten herself into. 

A/N : Thanks for reading!

Don't forget to vote! And be sure to leave a comment telling me what you think! I'd very much love to hear from you.

Happy Reading, Lovelies!