This starts at the end of Civil War. The goal of this story is to fix the mistakes of Infinity War, because there's no reason why our hearts needed to be ripped out of our chests.
There are Civil War spoilers.

Work Text:

Steve Rogers was feeling substantial amounts of guilt. He couldn't help but feel responsible for what happened to Rhodey. Although Steve wasn't the one who had sent the blast that paralyzed the Colonel, he knew that it would not have happened if he had signed those damn accords. No, he didn't regret not signing them…he knew he did the right thing by following what he believed. What he wasn't okay with (nor prepared for) were the severe consequences. Hadn't they already lost enough?
"Steve?"

Steve looked up from his lap to the troubled eyes of his lifelong friend…a friend he never thought he would have again. "Yes, Buck?"
"You're thinking about what Nat told you about Colonel Rhodes, aren't you, Punk?" The nickname came second nature from the assassin, but it did manage to bring a weak smile to the Captain's lips. There weren't words that could explain what it was like to have his 'Till the end of the Line' bud back, even if it's been 70 years.
James "Bucky" Barnes took his friend's silence as a sign his assumption was correct. He personally didn't feel too torn up over the casualty because that is what happened in the war, look at his own arm. But that didn't mean that Steve would see it the same way. His moral compass always was the stronger one of the two. Bucky did things because he was expected to, but Steve's actions were driven by a need to make the world a better place. If there was a way to check, Bucky would bet his right arm that Steve didn't have a selfish bone in his body.
Quickly checking their surroundings to make sure they were alone and once satisfied, Bucky stood over Steve with his arms crossed over his chest. "Have I told you yet how I was able to get free from Hydra's control over my body?"
Out of anything that Bucky could have said, that was one of the last things Steve had expected to come out of his mouth. "Sheer power and determination?" It may have sounded like a sarcastic answer, but it wasn't. It was just the best answer that automatically filled the blanks in his head.
Bucky chuckled darkly, shaking his head. "No. Hydra has a way of breaking the human spirit beyond repair. Not even God himself could have broken the control."
That didn't make sense, Steve thought to himself. His thoughts must have been transferred to the look on his face because Bucky gave him a sympathetic smile before grabbing a cheaply made plastic chair to sit backward in. Resting his arms over the back, he leaned forward a little bit, as if he was about to tell a secret. "It wasn't me. It wasn't God. It was someone who has the power to alter the connections in your body, whether that's to fix or mutilate."
Steve felt confused. That sounded like an incredibly dangerous person who should be found and dealt with before they went off the deep end and took out everyone within a 100-mile radius. "How's that even possible, Buck? What does this person have to do with you gaining control over your own actions?"
"It has everything to do with how I regained control over my own body and mind," Bucky answered patiently, his eyes going out of focus, clearly remembering the past. "She found me while I was on a mission in Botswana. Apparently, she was making her rounds around random villages in Africa, wanting to help those who couldn't get any from anywhere else or couldn't afford it."
Steve furrowed his brow, crossing his arms over his chest and leaned back in the creaky chair. For a second, he thought the back was going to break and his stomach dropped before he immediately recalibrated and sat up straight, hands resting on his knees. "Doctors Without Borders then?" he questioned, trying to keep on top of the story.
Bucky snorted, clearly amused by Steve's question. "God no. They would be so lucky to have such a person in their ranks. No, this woman Steve, she keeps to herself for her own protection. If word got out about her abilities, she would be taken hostage and used until she killed herself from exertion or was killed for not complying to another's orders. She doesn't take too kindly to being ordered around. It's kind of funny actually, seeing this 5'3 dame give a 6'4 man sass and put them in their place."

"You're obviously very fond of her," Steve mused, stroking his chin in thought trying to picture this woman in his mind.
Bucky had an easy-going smile on his face as he remembered the woman who saved him from himself. "She's an angel," he agreed, not even having to think about it. "I was at a safe house in Botswana when she came across me. She said that the amount of damage done to my mind was nearly palpable. So she somehow managed to knock me, a highly-trained assassin, out and dragged me to her place of residence. She didn't have much, just a small room with a bed and a backpack with scrubs and some other clothes that were appropriate for the area. With essentially no resources, she was able to get into my head and removed every single piece of shit that Hydra had put in me. Not even my trigger words would work-"
"Then how come you were triggered when Zemo spoke them to you?"
"Acting, Steve," Bucky was patient as ever, not minding that his story was once again interrupted. "We would have never know what he was planning unless he thought that I had….reverted, for lack of a better term, back to the empty slate of my mind."
Steve nodded thoughtfully at this information, impressed with how far his friend would go to see a mission through to the end. "So she is able to clear someone's mind of mental blocks, or does it go further than that?"
"So much more. More than either you or myself could ever comprehend." His dark eyes drifted towards the ceiling, bringing the memories of their conversations to the forefront of his mind. "When I asked, she said that she could literally see all the different connections in your body, whether that's the blood vessels, nerves or in my case, the neurons in my brain. Not only does she seem them, but she knows how every single connection is supposed to look and work and she can alter any part of those connections with little more than a thought. If I had to guess, I would say it goes even deeper than that."
Steve shifted uncomfortably in his chair, feeling once again nervous having someone so powerful running around without any sort of check and/or balances. "Do you know if she ever-"
Bucky held up a hand, effectively cutting the Captain off. "She's not a danger to anyone. She would never, not even unintentionally, hurt someone. She took an oath a long time ago to do no harm." He gently placed his hand over Steve's thigh, cutting off Steve's thought. "She only wants two things in this life. She wants to help those she is able to and not be caught. She took a huge risk in helping me, especially if Hydra caught word of someone who was able to take advantage of those connections."
After a quiet moment of thought, Steve spoke up. "How do we find her?"

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