A/N:

Hi everyone, :)

Woo, this is kind of exciting. This is the first time I'm going to be posting an Avengers story on FFN. (Once upon a time, I'd posted some one-shots but have since taken them down… my writing wasn't very good 10 years ago.) I've been working on this story here for the past few years, and now I'm setting her free into the world to be seen.

It's still a work in progress, as I'm constantly adding new material in between everything I've already written. I'm also going to start this off by being real with you guys; I'm not great at maintaining regular updates. Life happens. Sometimes updates will be weekly, and other times they'll be on back-to-back nights. I'll try my best not to go too long between updates.

Long story short, I hope you all enjoy my little story here.

Disclaimer: I don't own any of these characters (other than Ryan, my OC), all credit goes to Marvel and Disney.

Also, I'm going to try and be as MCU main timeline complacent, but there's going to be a couple of changes. For example, my prologue is set in 2006 when the failed mission she's referring to happened in 2009 in the MCU. That is all :)

Happy reading! Let me know what you think in the reviews!

Prologue – March 2006

Ryan liked to think that she had mastered the art of controlling her emotions over the years. It was necessary, in her line of work.

It was more efficient, not to linger too much over what was right or what was wrong. To bury the guilt so deep that she did not have to think about it or let in haunt her as time went on. Not to let herself get too comfortable, because what was given could always be taken away. It was easier to feel nothing at all. Though, she couldn't deny that there were a few individuals who'd broken through her wall in recent years. She could count on one hand the people she trusted enough to be even a fraction of the person she once was.

She was nothing like the girl who once stood alongside Captain America and the Howling commandos in second World War. That girl had been soft, inexperienced. She was easier to break. It's a mystery how that girl survived being held captive with the 107th and getting experimented on for weeks. Though, she did have Johann Shmidt and Arnim Zola to thank for her enhancements, the result of an untested super soldier serum and exposure to the Tesseract. Little did that girl know that what happened in that HYDRA base would alter the course of her life forever.

It wasn't until later that they discovered her enhancements, beyond the usual heightened strength and senses that came from the serum. It was by fluke, Ryan found out that she possessed some inexplicable healing abilities, after getting hit by a shot that should've killed her and having the wound heal itself within a few hours. It was like her body had been frozen in time, Ryan realizing after the turn of the decade that she hadn't changed at all. She hadn't aged since 1944. She also found that she'd developed an Adoptive Muscle Memory, where she could see, hear, or read something and immediately be able to replicate the action or commit it to memory. These abilities, paired with her apathetic tendencies, led her to become the most lethally efficient SHIELD asset in the organization.

However, not many people were aware of her existence. It was partly because she needed to create a few identities every decade or so before anyone could catch on to the fact that she wasn't aging normally. But the main reason was that Ryan handled the more high-level secret assignments; the ones that were off-book or too high profile. She had handled a good amount of SHIELD's dirty work over the last 60 years since she'd helped to form the secret government organization, she was unofficially credited with the most assassinations on behalf of SHIELD after all. It required one of the highest security clearances to even know about her, and a far higher one to be read in on her non-existent file.

The only ones other than her handler, DELTA teammates and the Director who knew of her and her abilities were the heads of departments, the secretary of state, the Strike Team Alpha who occasionally assisted on operations, and a select team of analysts. To everyone else, she was just another SHIELD agent who minded their own business. No one bothered her, and she didn't bother them.

It mattered even more now with this newfound purpose that she remained in control of her emotions. Ever since the failed extraction of a potential asset a few weeks ago, she committed herself to doing whatever it took to weed out a resurfaced enemy and recover something she'd thought she'd lost forever during the war. As awful as the circumstances may be, it reignited something within her. A drive and determination that had slowly faded as she'd turned into a machine. There were new important stakes at play.

She had called an off-books meeting with the Director of SHIELD 6 weeks after that failed mission out of Iran, ready to plead her case. It had been long enough since the mission that no one would think of it as odd or pick up on what she wanted to do. She was careful in choosing the location, a safe house somewhere in the middle of the woods in upstate New York. By the time she made it there, she could see smoke coming from the chimney, indicating that Fury was waiting for her. She took a long breath as she parked her car, because she wasn't going to take no for an answer.

She walked into the house to find Fury stirring something in a pot on the stove as he hummed along to the Motown song that was playing softly from the old radio in the living room, the smell of a homemade stew filling the small cabin. A fire was burning brightly in the fireplace that was situated in the center of the living room between two windows, along with the single light over the kitchen skin. The curtains were drawn, except for the one next to the dining table that had a view of the road leading up to the cottage. She was glad that the fire had been started beforehand, or it would've been rather cold inside considering they were in the middle of March. Ryan was never a fan of the cold.

He didn't turn when she walked in, focused on his task at hand. "The least you could do when you call off the grid meetings is show up on time." He remarked.

Ryan rolled her eyes. "It's snowing."

"I noticed."

She shrugged out of her boots and winter coat, hanging the coat on the hook on the paneled wall next to the door. She shook the snow out of her recently changed chestnut colored hair, running her fingers through the pin straight lock that went just past her shoulders. She then grabbed a scanner from the bag that she dropped by the door, going around the small space to make sure they had no ears on them. It was highly unlikely due to Fury now being the only other one who knew about this safehouse, but it was better to be safe than sorry. Satisfied when her search came up empty, she wandered into the kitchen ignoring Fury's assessing gaze to peek into the pot. "Looks to me like I'm right on time."

Ryan reached into a cupboard next to the stove, pulling out two bowls and plating them each some healthy servings of the stew. She brought the bowls over to the little table by the windows in the corner of the kitchen, watching as it continued to snow heavily outside. She took the seat that faced the road and the front door, out of habit. Fury sat across from her, kicking up his feet onto one of the extra chairs between them and settling in.

They dove into their meals while it was warm, nothing but the soft music from the stereo filling the silence. She wasn't surprised that the stew was delicious. She'd had the opportunity to taste Fury's cooking countless times over the last 20 years, from when she'd recruited him into SHIELD and he'd been her field partner in the late 80s, through more surveillance operations than she could count to many late-night dinners as they discussed their next steps in the organization to his promotion as Director of SHIELD. She considered Nick to be one of her genuine friends and trusted him with just about every secret. There was a reason she'd pushed for him to take up the Director position after the last one had retired at the turn of the century.

"What's this all about?" He asked, cutting through the bullshit only once they'd finished eating.

"I want to go after HYDRA and the Winter Soldier."

Fury didn't say anything at first, crossing his arms over his chest and keeping his steely eye on her. She met his gaze head on, letting him know that she was serious about this. "The Soldier's a Russian ghost story, propelled during the cold war to make Americans think twice and give credit to unresolved assassinations. People have tried to find him before to no success. He doesn't exist."

Ryan shook her head. "He's real. The Soldier is the one who caught up to us in Odessa and took out the engineer with the shot through Romanoff."

Fury narrowed his gaze. "The debrief report says you never got a clear visual of the assailant." Had it been aimed at anyone other than Ryan, they would've cowered in their seat. But she had known Fury long enough that he didn't intimidate her in the slightest.

"I lied." She admitted.

"And why would you do that?"

It was a simple question, but Ryan still hesitated for a moment before answering. "I knew him, from back in the day. Given that a handful of people knew about the extraction in the first place, I assumed that one of them sent the Soldier and was unaware of the connection to my past. I felt it best to keep that part to myself and pretend that I hadn't seen anything to be concerned about."

He absorbed the information silently, eye never leaving hers. She could practically see his mind racing, as he came to realize that there was someone at SHIELD who was not loyal. Someone at SHIELD had access to the Solider, using him under the radar to further their own agenda behind the scenes. "Where does HYDRA fit into all of this? I was under the impression that Captain America sacrificed himself to put an end to Hydra."

Ryan ensured that her face remained neutral. "That's what we all thought, when Ste- Cap defeated the Red Skull and sunk his plane. That is, until the engineer started rambling about how HYDRA was responsible for breeding chaos in the shadows over the last 60 years, hiding in plain sight throughout most government intelligence agencies. He found out that his organization was a front for a HYDRA cell, and that he wanted out. That's why he reached out to SHIELD in the first place. He thought he would be safe with us."

Fury still looked skeptical, and Ryan didn't blame him. She'd been sitting on this information for 6 weeks, trying to decide the best course of action to take. "And you found proof to back his claims?"

Ryan bit at her lip. "Not exactly."

Fury shot her an incredulous look. "Explain."

"I've been looking into it for weeks, and the most I've come up with is a top-secret science division within the KGB right up until they dissolved in 91. In the files I was able to find without triggering any alarms, there's mention of an asset, which I believe to be the Winter Soldier. After 91, it's like they just stopped existing. I think this division was a revival of HYDRA, and without the KBG to hide behind, they were forced to scatter and work within the shadows of our modern government agencies to further their agenda." Ryan explained as asked, telling him everything that she'd gathered thus far. "I haven't found anything for the last 18 years."

"What are you asking me to do here? If we deploy a task force to hunt down HYDRA, they'll double down on their efforts to hide."

"I know. Realistically, there's only one way to go about this…" Ryan sighed. "I want to run a solo deep cover black op."

"Absolutely not, Agent Stone." Fury spoke immediately, rejecting the idea.

"Nick, if you don't let me do this, I'm just going to leave SHIELD and do it on my own. If you do let me do this, I could still be useful to SHIELD and get to the bottom of it." Ryan protested. "Now that I've seen the Winter Soldier, I can't just let it slide. I've infiltrated so many terrorist organizations and brought them down. How would this be any different?"

Fury looked unimpressed by her question, because they were both aware that this was in a league of its own. If the engineer was correct, they were in for a world of trouble. "This one's personal for you. You'd advise against it if it was anyone else."

"You let Romanoff take out the Red Room. It doesn't get more personal than that." Ryan argued.

Fury rolled his eyes. "That was a condition of her defection to SHIELD, and you know it. She also had you, Barton, and Coulson to make sure everything went according to plan. You're talking about going after something we aren't even sure exists, on your own. Say you're wrong or you get caught digging, it could piss off a lot of very important people. Not to mention, they would have my head for authorizing it."

Ryan scoffed at the idea that she would be stupid enough to let herself be caught. She wanted to yell at him that it clearly did exist, but Fury was right. They didn't have any concrete evidence to warrant this type of operation. "I need to do this." She said quietly. "I have this feeling in my gut…that it's so much bigger than we think. If what the engineer said is true, we need to figure it out before they're strong enough to start overtaking our allies. Besides, it would be a black op, so go by the golden rule and deny that it ever happened."

Fury watched her for a long moment, taking a long breath. "Talk me through your plan. If it isn't horrible, I'll consider it."

A slow smile crept over Ryan's face.

She gave him a summary of what she wanted to do, and what she envisioned the timeline to be. She made it very clear that she would have to do things she couldn't tell him, and that she was going to have to let go of her moral compass (which was already questionable) even further to attract the right kind of attention. If everything went according to her plan, she would be welcomed with open arms into the organization she wanted to take down. From there, it was just a matter of gathering as much intel as possible and figuring out how deeply integrated into the government intelligence agencies they were and pulling all the roots. Easy.

"You want to be SHIELD's very own Hercules." Fury deduced.

"It's actually Heracles." She automatically commented. She'd been interested in Greek mythology, once upon a time. "But yes, that's the general idea."

He eyed her for a long time after that, neither of them breaking the silence. The wind outside the cabin howled, the light growing dim as the fire in the living room slowly lowered. Ryan began to worry that he wouldn't support her, and she would have to make good on her threat to leave SHIELD behind. Eventually, he stood and wandered over to the fire to throw some more wood in. It took almost immediately, reigniting light throughout the room. Then, he wandered into the kitchen and grabbed a bottle of brown liquor from the cabinet above the fridge and two glasses.

When he returned to the table, he cracked open the aged bottle of whiskey and poured a generous amount into both glasses. "The only way I say yes is if you carry on status quo with Delta. Check ins with Coulson, training with Romanoff, and Sunday dinners at Barton's new farm when you can. You're going to need to decompress with people you trust, or the cover will consume you."

Ryan frowned for a split second, before regaining control of her face. "What, you scared I'll get sucked into the dark side?"

The look that Fury shot her almost leveled her. "I've seen you crack, Stone. Having a bit of chosen family around doesn't hurt when you need to be reminded who you are."

"They can't know about this." She quickly cut in. It wasn't that she didn't trust her Delta teammates with her life. It was more so that she didn't want them to become collateral damage should anyone find out what she was up to. They could be used as leverage, and that wasn't good for anyone.

"I'm aware." Fury muttered sarcastically.

A few more moments passed in silence, before Ryan decided it was time to ask the most important question. "So, is that a 'go'?"

Nick sighed, giving her one last long look. "Do what you need to do." He nodded, finishing off what was left of the whiskey in his glass. "I expect to be kept in the loop."

Ryan nodded. "I'll tell you as much as I can."

It was official, she was going deep cover.

She hoped that it would be worth it, and that she would be able to save her old friend from what he had become. She made a promise then and there, to finish the work that Steve had started in the war. It was the least she could do, seeing as she had survived when he hadn't. She would weed out HYDRA once and for all, whatever it took. Tomorrow, everything would change.

But for the rest of tonight, she was content to drink with her friend and reminisce about the good old days, putting everything on the backburner to deal with later. They drank late into the night, and though Ryan couldn't feel the effect (thanks serum…), Fury eventually fell asleep on the sofa after polishing off the bottle. Ryan smiled, knowing that it meant the man trusted her implicitly to have his back enough to let his guard down.

She took it upon herself to triple check the security systems around the safehouse and restock the fire so it would continue to burn for the next few hours. She then turned off the light in the kitchen, before making her way into the bedroom to turn in for the night. She didn't doubt that Fury would disappear long before she would wake up the following morning.

As she settled into bed, she let her mind wander over plans for the coming months and how she would get to the bottom of everything. If everything went according to plan, this shouldn't take more than a few months. She'd deal with the few HYDRA agents, find the Winter Soldier and get everything back to the way it was meant to be. Easy.

Little did she know how wrong she was...