we are a nuclear reaction, part I

It happens like a nuclear reaction: one little collision cascading into a mass casualty of the very best variety, unstoppable from the moment it starts until the moment it spends itself out. There are, of course, a multitude of moments that lead to it: two years of build up that create the impetus for that first spark into pure energy, but it's nothing more than a touch, a brief graze of skin, that sends all the potential careening into existence while they are all but helpless to stop it. (Not that they want to, they throw themselves into the fallout fully aware that life in its aftermath will be nothing they've known before).

She's been at the lab all day, first to arrive and last to leave and he's just checking back in before heading out. He honestly hadn't expected anyone to still be there, had been on a run burning some excess energy but really, he shouldn't be surprised. Her back is turned to him, completely focused on the research she's sifting through and completely unaware that she has company, and it pulls a fond smile across his lips as he watches her for a long moment.

He's been doing this more often, pausing in the quiet seconds of the day to breathe her in, and the more he does it the more he wants to (and the more he wonders why it's taken him so damn long to notice, he's always been so smart). He's always known Caitlin is beautiful, but it catches his attention now in ways it never did before. He finds himself mesmerized by the way her curls trail across the bare skin of her neck, the way she chews her lower lip as she sorts through a problem in her data, the way she'll startle and then her lips will curl into a warm smile the second he announces his presence. Her eyes, her mannerisms, her legs, her smile—she's absolutely gorgeous.

And if that were all that it was, he would certainly be able to battle back the flames that these observations incite, but there's so much more to Caitlin Snow than her heart-stuttering appearance: she is brilliant, compassionate, utterly undeterrable and completely uncompromising. In short, everything about her adds fuel to the fire and he's been slowly smoldering for ages now.

Barry shakes away the thoughts, pushes them back into that place where they've been living (and growing and writhing below the surface) steadily for the last several months. Leaning casually against the doorframe, nestling in for the best vantage point for the reaction about to play out, he calls out a quiet "Hey Caitlin," and lets himself laugh aloud when she jumps in just the way he knew she would at the sound of his voice.

Sure enough, as she turns around there's a hand pressed to her chest but a smile on her face that's completely nullifying the scolding look she's attempting to give him. "You scared me," she breathes unnecessarily, though he doesn't mind—a tiny part of him caught up in thinking about better ways to leave her breathless (a tiny part he tries desperately to ignore).

Barry fixes a smile on his face that is insincerely contrite, knowing that Caitlin will read the expression accurately, and pushes himself off the doorframe and into the room. "Sorry about that," and the answering roll of her eyes tells him she knows he isn't. "Didn't actually expect you to still be here." Which is true: he left an hour ago for his run, when Dr. Wells and Cisco were packing up: he'd expected Caitlin to be right behind them, gone long before he'd returned (not that seeing her now is the least bit disappointing).

She just shakes her head, motioning back to the monitor. "Got caught up reading, as usual. But I was just about to head out and grab something to eat, want to join me?"

It's a silly question on several fronts: Barry Allen never turns down a meal and he never turns down a chance to spend some with Caitlin. Whatever else is crackling to life between them, she's one of his very best friends and there's never a dull moment when they're together. "You know I never turn down good food or better company," he teases, making his way over to grab their coats while Caitlin begins the task of shutting off all the monitors and nonessential equipment.

They meet in the middle (like they do on so many things) and tug on their jackets before beginning the short trek out of the lab. "I was thinking Chinese," Caitlin mentions after a moment, glancing up at him to read his expression. Barry can eat pretty much anything at anytime, so he's never exactly fussy about choices, but he still has preferences and she tries to defer to them whenever she can, even if he makes no demands (he's so damn selfless all the time, she nearly needs to trick him into thinking about himself every now and then—it would probably be more obnoxious if it wasn't also so endearing).

"Mmm," he smiles, knowing she'll be watching for it. "Take out and a movie?" It's become one of his favorite ways to spend an evening, stretched lazily across Caitlin's couch (sometimes with Cisco, sometimes without) eating straight from the container, watching Caitlin's nose wrinkle slightly as she accepts that he's not going to use a plate (and heckling her until she eventually caves, desperately hiding her smile as she plucks a dumpling straight from his box with her chopsticks) while a movie plays out on the screen of her television.

"If that's okay with you?"

It's a question she really shouldn't need to ask; he needs to get them to the point where she doesn't ask. As brilliant as she is, he thinks she should see how desperate he always is to spend time with her, how gladly he accepts any chance, but she never sees that about herself and it's frustrating and endearing and he's determined to change it someday. "Sounds like a perfect night to me," he settles on, bumping her shorter shoulder with his own. Contact is Caitlin's language, she works in science and resolutes and he knows it's harder to argue with what's physically tangible so he finds himself backing all his reassurances with a nudge, a hug or a brush of his arm. He also tries to tell himself it's not just an excuse to touch her, but he's not sure which theory is more plausible.

Either way, her smile is radiant even as she rolls her eyes, incorrectly assuming that he's just being overly dramatic. "Good thing you're so easy to please."

And he is, really truly is, as long as the thing doing the pleasing is Caitlin Snow (and isn't that an image he'll never get out of his mind?).

This will be a two-parter, which I'll be posting in the next few days. Part two will definitely be rated mature but I wanted to separate the scene leading up to it. (Which, by the way, this will be my first mature story so I'm a bit nervous, which is the other reason I wanted to split them up).

Hope you guys liked the start. As always, feedback is appreciated!

Take Care & Best Wishes,

A.O.R.