It was getting easier to sense when she was near.

That was his first clue that things were going too far. Treadstone had taught him many things over the years, one of which was how to use all of the senses the human body possessed to survey your surroundings. It was a skill that served him well in the five years since he'd started on this bloody path of destruction and death.

Meeting her was different.

Long, blond hair and brown eyes that could freeze you with a glance. He'd never met anyone quite like her before, not in his home town in rural Missouri or in the various places he'd been since. The first time they'd met was in Paris. He could remember Conklin standing next to her, explaining that she'd be his handler, his logistics. He denied it at the time but there was something about her that immediately set her apart from the others.

Maybe it was the set of her shoulders or the way her stance reflected a defensiveness that he couldn't put his finger on. Maybe it was her lips—full, pouty, and just the right amount of pink, set into a firm line that dared anyone to question her place in the program. She was young, younger than him but something about her seemed older, wise beyond her years.

She probably had a shitty childhood, he'd decided, and had to grow up at a very young age. Maybe her father was an alcoholic, her mother a party girl. Maybe she had younger siblings that she had to take care of. Any of these things would explain the hard set of her eyes, her lips, her shoulders.

He'd concluded that she was cold, calculated, and nothing-but-business.

It was the only time in five years that he'd been wrong about his first impression of someone.

"How have your…physical symptoms been since the last time we spoke?"

"The headaches?"

A nod of her head was his only confirmation.

"They still feel like a sledgehammer to the skull, why?"

She winced. It had become obvious to him that his first impression of her had been wrong. She put on a good show, but her emotions were always just waiting below the surface, ready to boil over. Sometimes, after these debriefing sessions, she'd give him a small, shy smile. It wasn't much, but it was a human showing him emotion and goddamnit if somedays he didn't live for those smiles.

"I can put in a request for stronger painkillers, but you're already at most of the maximum doses. I'm running out of other options," Her frown and furrowed brow were the only indication that this was bothering her.

"Conklin suggested I try sex," his tone was conversational, but it surprised him that this statement had come out of his mouth. He didn't catch himself off guard very often, and usually when he did it was when he was around her.

She hesitated only briefly before responding, the blush on her cheeks the only indication that they were discussing anything other than business. "It's worth a shot."

And so that's how it started. The fleeting glances, the subtle touches, the way the skin of her neck burned crimson when he walked into a room. He would trail her on her morning runs around the city, staying far enough back that it wouldn't attract attention. She could sense him there, like a shadow, and it both intrigued and infuriated her that this attraction was happening.

The first time they had sex was in his apartment in Paris. She raked her nails down his chiseled back as she came, head thrown back in ecstasy. He decided then that she should always look like that, and did his best to make it happen as often as possible.

His headaches gradually faded the more time he spent with her, a fact that he studiously ignored in the beginning.

When he went away on assignments she often lamented at her cold bed, the feeling of being incomplete so foreign and terrifying to her. They both knew what this was. There was no way that any attachment could happen, not in their line of work.

It was one evening in early spring that he was sitting at an outdoor café in Paris, the wind soft but cold, that he felt the hair on the back of his neck stand up. He looked up to see her walking past casually, scarf around her neck and hair in a wild halo around her head. In the bag at her side he detected the sight of her favorite brand of French wine and the outline of a box of her favorite macarons.

His body was responding to her physical presence in a way he'd never experienced before. If he could sense her that easily, if he knew her that well, they were in deep shit. He caught himself before he could call to her, watching her walk down the sidewalk with that familiar bounce to her step.

It wasn't three hours later that he found himself at her door, needing to be near her, to smell her, to listen to her breathe as she slept. She smiled when she opened the door, a small smile, so like the ones she'd given him back before they were so much more.

And he knew, without a doubt, that he was fucked.

"I love you," she'd whispered, even though they were alone, even though it felt like there was no one else in the world but them at that moment.

His eyes shut involuntarily. Hearing those words leave her lips was the sweetest torture he'd ever endured. Something he longed for but stubbornly dreaded all the same.

"I love you too," he choked, kissing her to distract her from the break in his voice, "so much, Nicky. I'll always come back to you."

It wasn't until years later that he proved how true that statement was.