Takes place a year after the crossover; if Ronnie is alive Caitlin doesn't know it.

Disclaimer: I do not own The Flash.

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Of all the metahumans they had faced so far, she was one of the more milder ones. It wasn't that she was intent on world domination or anything of the sort, on the contrary, she was content sitting in the sidelines and doing her work.

Making people fall in love.

Much unlike her parents.

(Someone had yet to explain the difference of love and lust to the poor girl.)

But before they could lock her away or minimise the effect of her touch she was determined to impart one last gift. She gave Barry a hug. The horror that permeated the looks of Cisco and Caitlin were enough to remind him just how dangerous that would be.

However, by that stage, it was too late. He had been infected.

They just didn't fully realise it.

"Are you sure you don't have any lingering affects?" Barry brushed her off, eyes rolling as Caitlin harangued him about the latest metahuman. He would have commented on his increased heart rate when in her proximity, with her hands liberally roaming his bare chest, he would have groaned out his urge to pull her against him, to have her be a whimpering, moaning, hot mess underneath him but he had long ago accepted these as normal.

He had long ago accepted this as a desire like no other.

(It wasn't the effects of a lust-inducing touch but a lust-affected mind.

And the fact he was in love with her.)

"Don't worry Caitlin, I won't ravage you without permission." He winked at her cheekily, his smile an ever-present fixture on his face with her around.

"I- what?" He took in the rosy hues of her cheeks, enjoying his ability to fluster the normally stoic doctor. "I was thinking of your dinner with Iris and Joe. We wouldn't want you to act upon your feelings for Eddie's fiancée."

"Oh, yeah. That. I forgot all about it."

And he truly did.

She looked at him worried, mentally reciting the symptoms to herself, checking whether temporary memory loss was one of them. He chuckled as he saw her do so, watching an unsettled look come across her face when no, it wasn't a symptom.

"I'm fine. I'm - Caitlin." She had opened her mouth to argue, but his hand on her shoulder had startled her into silence. Looking into his eyes, so soft and light, filled with optimism and hope, she felt herself relax. "I'm okay Caitlin." And she couldn't respond, not with him looking at her like that - like she could mean something more than just a friend and work colleague. She moved forward, to do what she wasn't quite sure, but it felt right, being near him. Being closer.

"Guys, where are you?" Breaking apart whatever moment they were having, Cisco's voice echoed down the halls. Pulling away from each other, Barry wandered back to a seat while Caitlin rushed to get her analysis complete before the morning. "Oh, there you both are." He didn't notice the disgruntled look on Barry's face, nor the flushed cheeks of Caitlin. Getting his stuff, he turned to them, picking up on the weird vibes they were giving off.

"So... Imma be heading off now, if any of you guys need a ride, now's the time to speak." Caitlin wordlessly shook her head, too invested in preparing her analysis and not focussing on Barry to answer properly.

"I think I'll stay down here with Caitlin for a while."

Nodding at Barry, he walked out of the labs, only stopping to remind Caitlin that Doctor Wells was out doing a thing and that she would need to lock up when the analysis was completed. As soon as Cisco left she turned on her heels and hissed at the man struck by lightning.

"You're staying with me? You have a dinner to get to, with Iris!" It hurt him to think that she believed he was still hung up on Iris, that she couldn't see how much he truly valued and loved her - Doctor Caitlin Snow. "You can't hide from her forever Barry."

"I'm not avoiding her Cait, and I can leave for later... right now, though, I'm going to stay down here, with you." And oh, if her heart didn't skip a beat when the nickname slipped through his lips, like it belonged there.

"Okay, well, don't forget to put your shirt back on then. You'll catch a cold down here."

(If his teasing smile wasn't so distracting she would have realised he never did so.

But it was and so she didn't. And thus, their fate was sealed.)

"Shouldn't you be heading off to Detective West's home now?" Her voice pulled him from his musings on her, on the way her hair curled perfectly, on her pouty lips that looked so damn kissable, on that shadow of pain that seemed to follow her around.

"Nah, I told them that I was feeling a little off tonight and couldn't make it." He truly was feeling different, the sensory overload that gradually building had finally hit him. Everything had been amplified, colours seemed brighter, scents seemed more pronounced. His mouth felt dry at the thought of determining whether she tasted as delicious as she smelled, and oh, did she smell heavenly. He was already feeling the heady effects of it and he was on the other side of the lab. The thought of being closer, of being utterly immersed in all that is Caitlin, was almost as agonising as not acting upon it.

"What?!" The distress should not have been as attractive as it was to him. Watching her jump up to her feet out of concern for him made him want to sweep her in his arms and kiss her fears away, to distract her from her worries using any means possible. "Why didn't you say anything earlier?"

"Relax Caitlin, I just didn't feel like spending time with the happy couple." She didn't look so convinced at the excuse, but his carefree smile seemed to soothe over any lingering worries. "I'm fine." Reluctantly conceding defeat in this argument she returned to her bench, analysing the chemical composition of the modified DNA of their metahuman and he had taken to watching her.

She could feel his piercing gaze focussed unwaveringly upon her and she felt self-conscious under his intense scrutiny.

"What is it?" She brushed a lock of hair behind her ear, something he noticed was a nervous habit of hers. He look in her lack of eye contact, her awkward shuffling. The tension of the room was nearing unbearable and really, why was he stopping himself from showing her how much he loved her?

"Have I ever told you that you look absolutely breathtaking?"

"What are you on about Barry?" She was in front of him immediately, concern permeating her expression. "You lied earlier didn't you? You are feeling off." Placing her hands on him again, she checked him like any personal physician would, noting any abnormalities that may have resulted. "Elevated heart rate, dilated pupils, slightly erratic breathing." She was murmuring to herself, trying to recall what they were symptoms of. And then she realised. "You were affected! It must have had a delayed affect, like the anger induced by Roy Bivolo. I need to call Cisco or Doctor Wells. Probably both. They need to know that you were affected by the metahuman."

"No!" The growl was almost indistinguishable as a word, the thought of her going to a man, any man that was not him for any reason, repulsive.

"Barry, they'll want to be here." He seemed to acquiesce to her request, but the moment she turned her back she was pressed against his chest, so very close to his bare chest, his heat radiating from him and lighting her on fire. She internally cursed her body's natural reaction to being so close to the individual who occupied many of her dreams and much of her heart. His grip on her was strong, and she learnt quickly that struggling against him was not the wisest course to take, his hands squeezing her waist as a warning to stop twisting. One hand rose up, running his fingers through her silky tresses, enjoying it's smoothness against his skin, pushing it all to one side.

"Barry, we need to call Cisco. You've been infected."

"Or we could just stay here, the both of us. Alone." He dropped his head against her neck, glad that she wasn't wearing anything high collared, that he had unimpeded access to her. Even knowing that he was affected by the metahuman's touch, aware that he was so close, and so very affectionate, she was still surprised when she felt the pressure of his moist lips against the side of her neck. Her heart leapt at the contact, and her fear and doubts were quickly met with the emotions she never thought she could feel after Ronnie, emotions that only Barry could bring out. Hope, love, lust. He continued his assault and slowly she could feel the worry seep out of her. His hands were running up and down her sides, teasing her, torturing her, its warmth melting the icy barriers around her heart, barriers that were now puddles by the wayside.

"Barry." It was a whimper, a plea - she wasn't quite so cognizant on whether she wanted him to continue or stop, but it escaped her lips all the same, echoing in the room.

"Dammit Caitlin." He all but growled it into her neck before lavishing the attention of his tongue, teeth and lips upon the skin beneath him. "It sounds so much more sexier in real life." His hands, so large and warm, slipped under the her untucked blouse, the temptation of feeling her soft, supple skin under his own too irresistible to deny. "Do you know how many times I would dream of you yelling my name, screaming it until your voice is hoarse so that the world can hear and know that you're mine. Of how many times I would wake up on the edge from just thinking about us, together." The vibrations rumbled through his chest and through her being, her knees almost buckling at his intensity, at how much much she wanted this - how much she wanted him to want this.

"Oh-" She wasn't sure whether he pulled or she pushed, but they were so incredibly close, so deliciously close, every ridge and plane of his body was against the curves of her own and it was short circuiting her mind. He hissed against her shoulder at the movement, nipping at her skin, the sweet torture messing with his control.

"God Caitlin, please tell me you feel it too, this thing between us. " His teeth tugged at her earlobe, revelling in the noises that she was making, hating that she felt the need to quieten them, that she felt the urge to make them stop. "Please tell me I'm not imagining it all." Her head rolled backwards against his shoulder, her eye lids to heavy to keep up. Everything required too much concentration and when the only thing she could focus upon is him and -oh.

His calloused fingers moved higher, brushing against her sensitive skin. The shudder that enveloped her body was uncontrollable, she was helpless against his relentless onslaught upon her senses.

"Barry..." It was a strangled moan, his name drawn out as she enjoyed having it roll over her tongue. He cursed against her neck, his body tense against her.

"Caitlin, you need to stop saying my name like that." She didn't realise he had pulled her straps down until she felt him exploring more of her skin. "You're killing me here."

But it seemed to be the only word her mouth seemed capable of forming, escaping unbidden from her lips once more as he continued to toy with her body and mind. He stilled as she did so and she could feel his smirk on her as she groaned at the displeasure of it. He spun her around, surprising her yet again.

"I did warn you." The glint in his eyes had her backing away slowly, jumping slightly when the felt the edge of her bench bump against the back of her thighs. He had watched her amused, using his speed to be by her immediately. And just as immediately he had whipped off the blouse that had teased him all night, leaving her in a simple white cotton bra.

She flinched, feeling exposed and vulnerable as his eyes raked her body. She moved to cover herself, doubts from her adolescence resurfacing, but the intense aura that surrounded him, an intensity directed towards her, stilled her movements.

His gaze roamed over her, pulling her in towards him and devouring her whole. She felt so inadequate; he lived with Iris, sexy, confident Iris West - he loved Iris - she couldn't dream to hold a candle to her. But the way he was looking at her, with such love and devotion, she couldn't help but waver in her beliefs.

"You're so beautiful." She could hear awe and amazement in his voice, his eyes unblinking, drinking her in. And in that moment she actually believed him. She felt beautiful. "Do you know how many times I have dreamt of this Doctor Snow?" The deep timbre of his voice was down right erotic, feeding her own desires, feeding her want for him. "The fantasies I've had of us, down here? I'd be sitting over there and you would walk up to me," her eyes had fluttered closed again by this stage, she was leaning against the bench behind her for strength. "You'd ask to do tests on me, on just how well I can use my speed." He didn't need to say anymore, her imagination already bombard her soul with images of just how she would have tested his speed and endurance.

"Barry please -" She hated the fact that she had been reduced to monosyllabic words, that his name was the only thing that would come to mind. But lord above, did she love the reactions it brought from him.

"Just tell me what you want and I'll do it." The words were muffled through the hazy fog of lust in her mind, the scent of their arousal and a muskiness that was utterly Barry assaulting her senses and holding her captive. "I'll do anything for you Caitlin, anything." His voice was strained, his hunger for her unquenchable, painful. Staying away from her, resisting it all, hurt. He needed her, but above all, he needed her to need him back.

"No-nothing." She stuttered the word, instantly mourning the loss of his warmth as he staggered backwards, lost and confused with a touch of heartbreak. Whether a noise escaped her lips or the cry was solely echoing in her mind she wasn't sure.

But it wasn't real - his feelings weren't true and heaven help her, she couldn't continue this charade and risk losing possibly the greatest friendship she had experienced throughout her life due to her lack of self-restraint.

"What?"

"None of this is true Barry - you're in love with Iris, this is the effects of the metahuman talking." It was a hard truth to swallow, but she would have to accept it. "Your only feelings for me are platonic and I can't take advantage of this in your system." She averted her eyes, tears stinging, heart breaking.

"No." She felt a shift in the atmosphere, her eyes drawn to the man in front of her once more. She noticed the determined glint in his eye, his set posture, the clenching of his jaw. She was unable to move and he stalked towards her, one hand tilting her head forward, eyes locking, breath catching, the other sliding around her waist, pulling her as close as physically possible. "This is me talking, okay? I love you and I have for quite a while now. And there is nothing platonic about the way I feel for you." His pupil's were dilated, his iris' a thin band of emerald surrounding the dark pool, but she still looked into them searchingly, hoping - needing - to find any sign that these were not the words of a man drunk on lust and pheromones. She didn't have time to find the answers she sought however because for the first time that night he kissed her lips.

The moment he made contact, she knew she was gone.

She felt as though she was drowning, helpless to fight everything that was Barry Allen.

(She had truly lost that battle the moment he asked why he never saw her smiling.)

His grip upon her waist tightened, pulling her flush against him, revelling in the way she seemed so responsive to every move. The skin contact between them left them both reeling with the sensation, it was an aphrodisiac like no other. It left them burning, on fire. The tension is the room was sizzling, She was unsure of everything but how he tasted, how he felt underneath her fingertips. She didn't know when she stopped standing and was instead sitting on the bench behind her, papers be damned. Lips moulding against his own, immersed in utter bliss, she wondered if the rest of her life could be as amazing as this.

(If she wasn't so high on the lips and touch and feel of Barry Allen she would have dismissed that thought instantly - she wasn't destined for happiness. But she was and so she let herself enjoy this moment of heaven.)

She had completely abandoned any pretense by this stage, her hands running through his dark locks, purring at the effect it was having on the hero holding her, legs were wrapped around his waist, her heels pushing him closer. He growled against her lips, one hand dropping to her lap, following the rise of her skirt up her thighs, teasing her with his fingers.

They were so engrossed in their activities, in each other, that none of them heard the lift descending or it's doors opening.

"Woah! I so totally called this by the way." Cisco's voice was jarring against the silence of the room, where the only previous noise was of their expressions of pleasure and the sounds of their hearts beating in sync.

Barry didn't flinch at the interruption, nipping and soothing his way down her jawline as she jerked in surprise. The night's events that did not include the feeling of his touch, lips or skin on her own came flooding back, along with her sense. Looking at Cisco and Doctor Wells, both with a rather amused expression on their faces she flushed and yelled at them before anything else mortifying could happen.

"Quick, hit him with the tranquiliser!"

And they did before Barry could process the words spilling out of Caitlin's mouth. The effects were strong and fast, the last thing he was able to do before falling unconscious was send a look of utter betrayal towards her, shattering the broken fragments of her heart further.

"Are we sure it is going to keep him knocked out?" Slipping on Barry's STAR Labs sweater, she felt both more relaxed and on edge, especially alone in the presence of Doctor Wells.

"It should. When we received your phone call I programmed the labs to slowly decrease the temperature of the room. The effect that the colder air is having on his body will allow the tranquiliser to leave his body at a slower rate." Doctor Wells wheeled himself around the lab, unnerving her more than what she thought was possible.

"So, how long do I have to create an anti-serum?"

"Ten minutes, give or take. Cisco's cuffing him up now in case luck is not on our side as it so rarely is."

"Well, It's all pheromones and biological chemical modifications, nothing I can't handle." The smile on her face felt as forced as the tone in her voice and - why did she feel the need to smile, pretend or otherwise? She turned her back towards him, unable to face her boss. "Cisco should be the one to administer the formula." She cleared her throat, attempting to inject a level of detachment in her voice. Because that is what she should have been, not secretly harbouring a love for the man who was currently handcuffed and unconscious in the labs next door. (Oh lord, how would she face him again? How could she look him in the eye after what had just taken place?). "He should be safe given that I was the one Barry attached to. If I was off or my dosage wasn't high enough-" She took a deep breath, attempting to calm herself down. "Well, It would be better for everyone involved if it was Cisco." He nodded, his gaze telling her he knew quite a lot more than what she was comfortable with.

"Of course. Oh and Caitlin -" Her breath caught, fear at what would follow flooding her system. "It was quite ingenious to enable your phone to take audio commands like that, good job." And with that, Doctor Wells rolled away, leaving her to finish the anti-serum in relative silence, the only noise heard by the geneticist being the sound of her own heart breaking.

(She was able to determine the correct chemicals and ratio required in four minutes, it was mixed up in an additional five. She left the vial on her table, knocked on the door to alert Cisco to her successful formula and calmly walked out of STAR Labs.

The fact that she didn't come to work the next day due to unforseen circumstances had nothing to do with the events of that night.

Absolutely none.)