Cross is instantly able to recall the exact number of times Dr. Shearing examined him prior to the events of the Bourne Legacy. While this may be just a result of his enhanced mental faculties, I decided to interpret it as a possible preoccupation with his lady doctor :) This fic is an attempt to flesh out some of their history and how it impacts their relationship both during and after the events in the film. Thanks for reading!

Prologue

It had been surreal. The new sense of awareness that crept through his conscious mind was unlike anything he had experienced before. He found himself having new thoughts, ideas and reactions; his daily interactions with his doctors and instructors opened his mind to possibilities he had never imagined.

Movement and reason happened faster and with more accuracy. His fear of tests and physical evaluations eventually faded away, replaced with a voracious need to satisfy his superiors, those who had granted him this seemingly priceless opportunity. Upon achieving operational status, this need manifested itself in a near-perfect performance record, as he completed mission after mission with robotic consistency. It was during this time however, that Aaron Cross first began to feel the bars of his new cage.

No empathy, they said. Not with the soldiers he occasionally worked with and especially not with the people he regularly killed. This was despite the fact that they frequently asked him to complete missions with massive amounts of collateral damage. He privately began to question his orders and his purpose in the program. Was he truly helping his country? Was he helping to do good in the world? When his kill count reached 200, he began to doubt. After blowing apart a health clinic containing women, children and suspected terrorists, he began to know. Byer spoke of being a 'sin eater', but Aaron understood what he really was becoming. He was losing grip on his own identity. His new realm of awareness was turning out to be as much of a curse as it was a blessing, and so he resolved to carve a place for himself outside of the program. He put together the means to exist on his own, stashing money and multiple identities in caches throughout the countries he worked in. The one issue he could not resolve was the chems. They rationed him out so precisely that he had to return to the Maryland clinic whether he liked it or not - although sometimes he did like it, but only when she did his spec work-ups. She was another thing that illuminated the limits of his existence within the program; he was never going to be with a woman like that, in the ways he occasionally fantasized about. As he waited in the parking lot across the street, watching her enter at the facility's front gate, he decided now was as good a time as ever to check in.

Dr. Marta Shearing knew the terms of her employment so thoroughly she felt like she could recite them from memory. It was the most extensive non-disclosure agreement she'd ever signed. She wasn't allowed to know what the program participants did upon leaving her lab, and the longer she worked there, the more she suspected that she didn't want to know. She knew what she was manipulating them to become, but what they actually did with their enhanced bodies seemed a thing apart. Compartmentalizing and rationalizing her actions became a part of her daily routine, most especially when any of the participants checked in. She never asked unnecessary questions or engaged in friendly conversation, and for the most part, neither did the men. Except for number Five. He was a chatty bastard, but she privately considered him to be her favourite. He had demonstrated the full potential of her viral genetic enhancement research. She remembered his first few weeks in the program; his progress was a personal triumph for her, and she looked forward to obtaining his results every time he came to the facility. So when security announced his arrival shortly after she made it in, she thought it was a good start to her day.

Aaron sat still on the examination table, aware of being observed from the other side of the glass. He kept his breathing even and his pulse slow; he never wanted to let on that he was excited to see her. Although he was, and had been since their first meeting. He could remember her smile and clinical touch in the early days of the program and had eventually associated her with his growing mental and physical capacities. It was her work, the chems, so as much as he had come to despise his handlers, he kept her separate from them in his mind. He suspected she distanced herself from the moral quandaries surrounding her research and the participants, but that did not diminish the gift she had given him. To distract himself from his current surroundings, he let his mind drift. Their first encounter was a watershed memory for him - it was when he had first realized his emerging mental acuity.

She entered through the other door – not the one he came through. Hair up in a bun and wavy bangs falling over her heart-shaped face, she was the most beautiful person he'd seen in months.

"Hello. I'm going to take some blood, test your reflexes and run some basic cognitive exercises today. Lay down please – I need your left arm." He complied, watching her as she moved around the room, preparing a syringe and swabbing his skin.

"What's your name doctor?" She looked at him, slightly startled. It left him feeling uneasy, as not many people in the program reacted like that – in fact, no one reacted like that, as if they didn't know what to say to him.

"I'm afraid I can't discuss that with you.. it's against policy."

"Do you always follow policy doc?"

"Yes. Now please make a fist, I need a vein to draw blood."

"Yes ma'am." His arm showed signs of his recent training regimen; bruises and scabs criss-crossed his skin. She glanced at the marks, muttering under her breath as she tried to find a good vein. He tensed and then relaxed as she completed her work. They moved on, and by the time she finished the cognitive exercises, Aaron had taken note of his fluidity and comfort in speaking with her, as well as her surprise in his responses. She took furious notes and told him of his progress; he had scored much higher on the exercises than expected and she was pleased with his performance. It was the first time anyone had praised him in this way, after a test, and he took it to heart. He left the room with his head a bit higher than when he'd gone in.

Fours years later, he knew his preoccupation with her had moved beyond gratitude and into more dangerous territory – and that it had not gone unnoticed by his superiors. It earned him a stern lecture on the repercussions of forming attachments, which ironically heightened his desire to know her outside of the program. However, in the interest of protecting the both of them, he had clamped down on his feelings for her to convince those watching him that he understood their warning. His medical exams remained the only time he felt he could safely see her, and as she walked in the room, he had to remind himself to act normally.

Marta felt eyes on her the moment she opened the door. The last few visits had seen a change in his behaviour – his normal banter had subsided to wry one-liners that left her feeling slightly bereft, although she could not explain why. His shirt was already off, displaying his considerable physique; going over her notes, she decided to do a brief once-over to check the state of his previous injuries. She recalled a particularly nasty laceration across the inside of his right palm, one that had almost severed the tendons and cost him the use of his hand. Moving to stand in front of him, she reached out to inspect the wound. It was only when she felt the heat of his skin that she realized she had forgotten to put on her latex gloves. She quickly looked up into his face to find him staring back, his eyes guarded. Flustered, she snapped on a pair of gloves and moved back to check his hand. It was halfway healed, with a raised, puckered scab marking his skin. She proceeded to check over the rest of his torso, but found that she couldn't regain her usual clinical demeanor – she was hyperaware of his closeness and heat. As her hands angled his head to examine a cut across his cheekbone, a blush rose up her neck, and his eyes immediately zeroed in on it. A small smirk flickered across his face, but he remained silent. She brusquely finished her once-over and told him she needed to put him under for a full spec work-up. He lay back and let her do as she pleased. When he woke, the examination room was empty except for his cell phone, which was signaling an incoming assignment from Byer. The next time he saw her, months later, her blushes were gone and her detached persona was back in place.