A/N: My first Fringe fic – Peter and Olivia have such a fascinating relationship to begin with and with the introduction of this new… evil!Peter sparked me enough to write.

Disclaimer: I do not own Fringe nor am I associated with J.J. Abrams, Joshua Jackson, Anna Torv or John Noble.

Loving a Stranger

She meant what she said that night in the yard, how she didn't want him, didn't want to be with him. He was… tainted. Damaged goods. How could she want him when a better, happier version of herself had already had him?

She changed her mind though. Slowly, with time, as she saw him loving her from an arm's length away. They opened up to each other, a fraction at a time, allowing small glimpses of the big picture.

Olivia sat with her feet tucked under her on the couch, the shiny white walls of her new apartment barely even better than the memories and torment of her old one. She had meant to keep everyone out, at least for a while, but cases had sprung up and before she knew it, Astrid, Walter and Peter had all made appearances. Tonight, it was Peter, much to her dismay. She typed on her laptop, studiously ignoring him under the guise of working devotedly.

He, however, didn't bother to hide his watching her. He did that a lot lately, almost as though he meant to make her uncomfortable –though she knew that couldn't be it. Peter had been so guilty when he realized how he'd hurt her, even unintentionally, there was no way he could ever hurt her on purpose. Still, the way he looked at her these days, stared as though trying to figure out what made her tick-

"This is crazy, Olivia." His voice was dry and startling in the stale, silent room.

She looked up in surprise, eyebrows lifting. "Isn't that a bit of an understatement? Our lives are more than crazy," she murmured coolly.

"Us. This," he gestured between them, "is crazy. There is no reason for you to hate me. No one else knew she wasn't you." He growled quietly in frustration, his eyes glassy with what she assumed was anger.

Olivia gritted her teeth. "Do you really want to go there, Peter? I don't hate you, but if you want to talk about this, if you want to pour salt in these wounds, I just might start."

Peter sat forward, hands folded, elbows resting on his knees. "I think it's about time we talked about it, actually."

She snapped her laptop shut with a furious click and tossed it onto the seat beside her. "Well I don't. I do think you should leave now, though."

He stood slowly, nudging the coffee table out of the way with his foot and leaning over her ominously, hands braced on the back of the couch, trapping her. "No." The solitary word hung between them, full of double meanings and overwhelming emotions.

Olivia felt the sudden desperate urge to slap him, to let her cold, logical understanding be replaced by raw anger. Her fingers twitched but something in his face kept her from unleashing. "What do you mean, no?" she demanded, voice barely controlled and steady.

"I mean I want you. I mean I'm sick of waiting for you to remember you wanted me first," Peter growled, catching her chin in his hand. "You remember that, Livia? You remember begging me to come back and be with you?"

She closed her eyes over stinging tears, wrenching away from his touch as she wondered at how he could be so cruel as to bring up Over There. "Too much has happened, Peter. Just leave me alone."

"We both know you still want me," he whispered, ducking his head, lips hovering over hers. "You would have found a way to stop working with me otherwise. Stuck me in a lab at Massive Dynamics or had-"

Olivia pressed her lips to his abruptly, hands grabbing at his face, tugging him closer. She traced his lips with her tongue until he let her in, resting a knee on the soft sofa beside her. "Livia… Livia…" he whispered, cupping her cheek in his hand as he pulled her down on top of him. "I've missed you so much…"

She didn't speak, only crawled over him, hands sliding onto the arm of the couch as she trailed her lips down his throat. Peter brought his hands up, fingers tangling in her hair, one sliding down her back. He kept up a steady stream of whispers in her ear, almost too deeply invested in reminding her he still loved her. Nipping at his bottom lip, Olivia tried to shut him up, tried to make it less romantic and meaningful but they both knew he had won her over long ago.

His hands moved onto her hips, tugging at the soft material there until she reached down to help him, her small, pale hands resting over his. She met his eyes for just a moment and they shone, glimmered, his smile oddly knowing. "What?" she whispered, unnerved.

"Nothing. You're just beautiful," he whispered back, pulling her hips down to meet his.

Olivia gasped in surprise, her eyes closing and her hands tightening in his shirt. "Peter…" she moaned, "Oh, Peter…" Blond hair fell into her eyes as she ducked her head.

He curled his hands around her thighs, gently grinding against her until she scrabbled at his pants, desperately needing hot, solid contact. Olivia undressed him hurriedly, shoving his pants to the floor and feeling a tremor of lust run through her as he pushed inside her. "Oh yes-Oh Peter, that's-" He let her ramble, not even listening as his eyes closed, relishing the feel of her around him.

Peter slid one hand beneath her shirt, spanning her back as he pulled her down to lay flat on top of him. Her fingers knit in his shirt, a soft whimper against his throat throwing off his steady rhythm. He groaned quietly, sucking her earlobe in between his lips, his eyes blissfully closed.

Olivia arched her back sharply, felt him smile against her skin as he increased the intensity, the heat, the pressure. His hand curved down over her ass, the long hem of her shirt still not enough to keep her decent, (and certainly not now, with him on her, under her, inside her.) Her rambling became a whispered chant of yeses, over and over, breathing into his mouth before she clenched him tightly, moaning her pleasure as he rocked her to the edge and then sent her plummeting over the side, sensible nails digging into his arms. He came with a soft sigh of his own, smoothing her hair down with one hand as they relaxed.

Sensing her sleepiness, he sat up, gently depositing her on the sofa and covering her with a blanket. "Night Livia," he whispered, kissing her cheek.

She didn't think it odd that he didn't spend the night until the next morning when sun shone through her window, alerting her slowly to the delicious ache between her legs but the quiet stillness of her apartment all at the same time.

After two weeks worth of hot, sticky nights, she would confront Walter in the lab and demand to know what was wrong with Peter. (Though the nights were hot and sticky, the mornings were cold and empty, the 3 am goodbyes uncaring and mechanical.) He would feign innocence but eventually she would drag the truth from him, that he simply didn't know. That the machine had some kind of a grip on Peter and as he had affected it, it had irrevocably affected him.

She would tell him he was wrong and storm from the room. Astrid would find her slumped over a desk in the office late that evening, her cheeks streaked with tears, her eyes puffy and swollen and a copy of the machine sketch torn into angry shreds.

Walter wasn't wrong, though. Eventually she would realize that. In the meantime, Peter would watch the chaos he had created in her life and smirk with satisfaction, a spark of pride lighting up his recently weaponized heart as he gloried in the sweetness of revenge.

The true Peter, buried deep inside, would know it was irrational and cruel to blame this – his – Olivia for his gullibility but this Peter could only see ginger and gold as one. This Peter looked at her and felt only anger, not love, not even lust. He touched her and only wanted her destruction. Killing her would be easy, but too quick, would attract too much attention and besides, the tiny bit of Peter that still remained would never allow it. But this was better anyhow. Replacing the man she loved with a stranger, right under her nose. An eye for an eye.