~Author's Note~

Yeah . . . so I have no idea where this came from. I mean I started out in the Flash fandom with snowbarry and then switched over to westallen but it's cool though. I like them both so it's all good. Westallen still my favorite though. XD

Anyway, I hope everyone enjoys and reviews would be great. :)

Rated Teen for mature scenes, like two curse words, small mention of injury, as well as some sexual moments and innuendos.

Notes: I don't know when exactly I first came up with this idea and started writing it but it was definitely before the season finale so I'm gonna say this was written before 3x22/3x23 aired. This is also a Future!AU story—kinda-not-really—and Barry is 34 in this while Caitlin is 35 (estimated ages from what I could calculate and I figured Caitlin is just older than Barry on the show 'cause I don't know she just acts older).

Razor Blade

Bolt of lightning in the night
Speed of light, you won't realize
You've been struck 'til you see the flame
She won't cut you like a knife, like a knife
That little look in her eyes will
Cut you like a razor blade

It's 2023.

There's a building off 34th Street that's frozen from the front entrance to the back exit, and she thinks there were five (no, seven, maybe?) people mulling around inside before she sealed it shut. Don't get her wrong, killing gives her an edge, killing fills her with an adrenaline nothing else can conquer, but sometimes she just likes to watch. Sometimes she likes to watch as her victims struggle for their last breath, or attempt to crawl to some help too far away.

Movies over-dramatize that, you know.

Most of the time, they're barely able to get three inches.

As she watches them through the thick wall in front her, reflections blurred and twisted from the jagged coating of ice, she wonders what's keeping him. He's usually there before she can even think about icing anything.

But just as she's thinking it, just as she's thinking maybe he's finally given up on her after all these years, she hears him appear behind her. It's pathetically easy to tell when the Flash approaches. The lightning is like a fresh soda being opened; it bubbles and fizzles and cracks. The ground seems to rumble beneath him as he thunders places, the Speed Force within him wholly refusing to be quiet.

"Frost."

She turns when his deep voice booms her name, lips pulling upwards on their own account. "Flash," she echoes sarcastically, "rough day?" She hears him grunt, but it sounds oddly like a chuckle.

"You don't know the half of it." He cracks his knuckles but it's not needed.

She's never been scared of him. He's never hurt her. She did give him a black eye one time though—and severely injured his leg another. Impaled him in the spleen a few years ago, broke his left arm five months ago. Frostbite was a big one too. She's hurt him. But he's never hurt her.

"How many?" He asks, but it sounds tired, worn.

She considers lying. She considers saying don't even bother, they're all dead by now but that sliver of good still in her prevails. "I don't know. Seven?" She sees the short nod of his head before he's off, zipping and zooming and running.

She starts to walk away.

Her footprints leave small ice-outlines on the pavement. When she makes it to an alleyway that's out of view from the police cars pulling up to the crime scene, she pauses and waits. He flashes in front of her a few seconds later, staring her down.

His eyes hold her in place as he takes his time moving towards her, right hand grabbing her wrist. His fingertips almost instantly freeze to her skin, but he's used to it by now. All it takes is a little vibrating on his part and he's fine. "Two were dead," he rasps lowly, and she's not quite sure if the disgust in his voice is directed at her or himself. Probably both, she muses as he continues to look at her. She stares right back and scoffs.

"So?"

Abruptly, he pulls her to his lips, kissing her roughly. She's surprised at his sudden action but at the same time not as she kisses him back just as intensely. She careful to control her cold and he's careful to keep his body temperature high and without any warning he flashes them down the alleyway more, her back hitting the wall. She groans and it causes him to pull back, breathing heavily as he keeps his body pressed against hers.

"Are you okay?" He inquires bluntly, Killer Frost nodding and capturing his lips again before he can say anything else. Things progress quickly from there and they only force themselves to stop when his suit is halfway off his body and her top comes off. They always stop before things can go too far. When both are back to proper etiquette, he faces her a final time.

"You killed two people," he repeats, almost distantly.

She nods. "Killer Frost, remember?"

He nods too. "Yeah. I remember." He turns to go but looks back before he does, their eyes locking. "Stop killing," he says and she can't help but laugh as he disappears.

They're older now. He's lost his lean figure and she's lost herself. He's fast. He's—he's beyond fast. He's truly the fastest man alive now and then some. He does his best to keep his face freshly shaven and keep the Speed Force at peace. His arms are big and his chest is bigger. Muscle covers his body, and his hair is shorter now.

She's a killer that lives up to her name. Her hair is longer and her face is more drawn, but her heart is as cold as ever. Her hair is pure white, her lips pure blue.

He's the Flash. She's Killer Frost. Nothing more, nothing less for either.

The next time she sees him she's dragging a fingernail down the cheek of a dead police officer who's slumped against the wall, head lolled forwards. His skin is purple and cool to the touch. As she turns away from her latest victim the Flash appears in front of her, fatigue in his eyes. He looks around her body and sees the police officer, extremely thankful it's not Joe.

Not that Killer Frost would ever pass that line, it's just the thought that comes to the front of his mind whenever he sees a triumphant meta-human and a police badge.

"Tired?" She questions, flattening down her skirt.

He looks like he doesn't want to answer and evades having to easily enough.

"Who is he? Dirty cop?"

She chuckles, a shiver running up her spine, "Oh dirty indeed. He wanted more than I was willing to give and got a little . . . too handsy." She shrugs, "Had to put him down." She sees the Flash stiffen but doesn't comment.

"Frost—"

"Hey, it was either him or me. He had a gun and was listening to what was below the belt instead of what was above it." He stares at her a moment, and she can nearly hear the gears working in his head. He flashes to her, catching her off-guard, and kisses her—hard and quick—on the lips. She grips his bicep for barely a fleeing second before he's a few feet away from her again.

"I'm glad you're okay." Killer Frost tries to say something but finds that words fail her and the Flash takes her silence as a reply. "Stop killing," he repeats, same as the last time they saw each other, "please stop killing."

With that, he's gone and Killer Frost is left with the dead cop and the steady pound of her heart.

Savitar killed Iris, in case you were too stupid to figure it out by now.

He murdered her in cold blood and broke Barry Allen. But Barry had been to the future, and he refused to turn into that lonely man that resided there; so he fought and fought and Cisco didn't lose his hands. Team Flash didn't fall apart. Killer Frost never got caught. He did succeed in trapping Savitar in the Speed Force, though it took a while.

The future changed, and yet the future stayed the same.

A lot of things happened through the years after Savitar's imprisonment.

In 2018, Cisco and Cindy started dating officially, finally. Apparently he won her over with a tray of cookies and all seven Star Wars movies in his apartment. In 2019, Wally found himself ten times faster than the Flash, and able to visit the Speed Force at will. In 2020, Julian moved away. To Coast City, if Killer Frost remembers correctly, which is still close by. Maybe that's on purpose. Maybe he still hopes she's Caitlin on the inside. She's not.

In 2021, Singh was shot in a mugging and Joe became the new police captain at CCPD. In 2022, the Flash almost died in an ambush by seven different meta-humans. They overpowered him and tortured him until he wasn't breathing, and by the time Team Flash found him—Cisco and Joe were lucky they were able to get him breathing again. Killer Frost was asked to assist them, the meta-humans. They wanted her help in beating Central City's hero senseless. She said no. She also realized that Killer Frost made that decision, not Caitlin Snow. Caitlin Snow had been dead inside of her for years. But Killer Frost wasn't, and maybe, just maybe, Killer Frost had a soft spot for the Flash. Just maybe.

In 2023, the Flash and Killer Frost found themselves kissing each other a lot more than what was proper for a supposed hero and villain.

Was it wrong that they both enjoyed it too?

He's exhausted when he meets her at their meeting place, which is a neglected motel about a half-mile outside the city, and from the moment he runs in she can feel the Speed Force sucking energy from her like a leech.

"Knock it off," she barks as soon as he is in eyesight.

He doesn't even regard her, instead taking a seat on the beat up couch a few feet away from her. "Sorry," he slurs after a minute and the feeling lessens around her but still persists. She rolls her eyes and takes a seat next to him, his head slumping into her lap.

She brushes a hand through his messy hair, windswept from a day full of running and fighting, and sighs. He hums when he hears her exhale, closed eyelids quickly opening again. Killer Frost glances down at his face for a moment before looking back up and staring at a spot on the far wall that's extremely interesting all of a sudden.

"Frost," he whispers, lifting a hand up and swiping a thumb across her chin. She shakes her head, continuing to stare at the wall. Cracks swirl and twist across it, and there's tack-holes covering almost the entire midsection of the white wallpaper. Flash reaches his hand up again, this time taking ahold of her cheek and attempting to get her to look down at him.

She refuses and rips her head from his grip, even going as far as pushing him off her and standing up. The Flash barely has time to react and catch himself before he hits the floor, not expecting her abrupt emotion.

Killer Frost paces to the other side of the room swiftly, now face-to-face with the ugly wall. She rests a hand against it and her eyes slide shut for a second, mind heavy with thoughts and memories. She's a killer, but he makes her not feel like one. She's a murderer—same as Reverse Flash, the man who killed his mother—but he acts as if she's not.

She jumps when his arms encircle her from behind, encasing her in a safe cocoon she never wants to leave. He also deserves better than her. He deserves anyone else but her. He deserves Iris. She relaxes in his hold, leaning back and resting her head on his chest. He kisses her hair.

He deserves Iris, but Iris is dead. Ronnie's dead too. Hunter was a fraud. Julian tried until he couldn't try anymore. She wonders if she still deserves them. She wonders if she could ever deserve Ronnie again.

They rarely have moments like these, all comfort and quiet, instead of their usual rough and quick. She finds herself wishing they had more moments like this one. He mumbles something into her hair that she misses, only able to her the profound grumble of his voice instead.

"What?" She inquires softly, not quite sure why they're being so discreet when nearly the whole motel is vacant.

"Stop killing," he begs in a whisper, "you'd feel so much better."

The sad thing is that she knows he's right.

He doesn't mention the tear that slips down her cheek. She doesn't either.

He doesn't call her Caitlin anymore. He doesn't ever dare to call her Caitlin. Sometimes he gets defensive or angry when she slips and calls him Barry. Because Barry was for Iris and Iris is still apart of him and a part of him Killer Frost will never dare to touch. She's afraid she'll freeze it, and lose the only Barry-Allen part of him left.

He gets hurt bad one night. An automatic shot a little too fast for his tired reflexes to catch. She's busy downing one bottle of beer after another in the back of a bar, no one daring to stop her because the frozen body of the bartender lays a few inches away from her heels.

After downing yet another bottle of alcohol, she meets the terrified eyes of a good-looking waiter across the room. She ushers him over with a wave of her finger, and he nearly trips three times getting over to her. She smiles when he reaches her and just as she opens her mouth to tell him to bring her some chicken from the kitchen, a flash of red fills her vison.

She's picked up and brought to his apartment in a flurry of colors, and by the time she's able to see again there's a First-Aid kit in front of her and a bleeding Flash sitting on the toilet lid behind her. She whips around, about to let him have it for interrupting her about-to-be-meal, but pauses when she sees the blood pooling underneath his suit's material.

From her quick look-over, there's at least four bullets scattered from his shoulder to his stomach. She meets his eyes wearily. "How did—"

"I wasn't—wasn't paying attention as much as I-I usually do at a bank robbery and—"

He winces, and it cuts him off. He grabs at his shoulder, but recoils as soon as his fingers brush his body. She understands what he's doing, it's common for anyone who's seriously hurt. He's trying to bring himself some relief, but she also knows it's not smart for someone to do so when they're injured.

Killer Frost feels something pool in her stomach for the speedster. And as he goes to try and grip his stomach, she grabs his hand and stops him. She locks eyes with him, pushing his hand down to his side. "Don't touch."

He stares at her for a minute, searching for an underlying motive. He doesn't find one. By the time she's opening up the First-Aid kit and stripping him of the top half of his suit, he's thankful she's not the killer she used to be. She still kills, but she's not how she used to be either.

"You're not a killer anymore," he says, and his eyes widen when she creates a long icicle on the tip of her finger. A small smirk crosses her face at his apprehensive look as she looks for the first bullet location.

"There was no scissors or scalpel in with the kit. It's clean. Pure ice. Don't look so scared, Flash. Don't you trust me?" It's meant to be a joke but apparently the Flash doesn't take it that way.

"I-I trust you."

Killer Frost says nothing, instead plunging the icicle into his skin. He gasps and clutches at something, anything—which just so happens to be her—and groans from the pain. His hands grip her hips and it's hard to keep her lips from curling into a smile. Before she starts digging around for the first of four bullets, she answers his past declaration.

"You say I'm not a killer anymore?"

He doesn't hesitate. "No. Not anymore."

She does smile this time. "I didn't just kill the bartender, Flash. There were three other patrons frozen out back." The Flash shakes his head before allowing it to fall onto her shoulder.

"Just stop killing," he murmurs, but Killer Frost ignores him and instead finds and yanks the first bullet out of his shoulder. His scream echoes through the apartment.

She could kill him. It would be so easy. She could make a dagger out of ice and slide it across his throat and that would be that. Even the Speed Force wouldn't be able to stop her, and she be free of him and his annoying pleas to stop killing, Frost.

She rolls her eyes at the thought.

And then wonders why she doesn't just do it.

She accidentally calls him Barry one late night. She's on top of him, hands memorizing his torso and lips unrelenting against his mouth. His left hand snakes a little too low and then she says it—she fucking says it—and the moment is shattered into a billion tiny pieces.

He scatters from her like he's gotten burnt by fire, her chest hitting the cushions of the sofa with a thump as he flashes to the other side of the room, holding his head. She lefts herself up by the elbows and turns her head towards him, heart racing.

He doesn't kill, she reminds herself, though the look in his eyes is warped by pain and misery.

Warped by the real man buried underneath the suit of armor. "Flash." She says, keeping her emotions in check the best she can, "I'm sorry." He shakes his head, cloudy eyes barely able to meet hers.

"You—You don't call me t-that!" He bellows suddenly, a tremble to his deep tone.

"You don't call me that!" He says again, stronger.

Killer Frost nods, keeping her composure steady. "Okay," she replies quietly, because she already knows but what else can she say? "Okay."

She has a chance to kill somebody but doesn't and gets stabbed in the thigh instead. He finds her bloody and lethargic behind a building and instantly rushes her back to his apartment to fix her up.

"Why didn't you do something?" He asks angrily as he pulls her skirt off and throws it across the room. "You're Killer Frost and some guy with a knife can do this to you?"

He's obviously livid and stressed and upset out of his mind. His hands are running down her leg in search of other injuries and when he doesn't find anything else he returns to the gash and starts cleaning it. His eyes hold the same fire behind them like they did when saving Iris was his top priority.

"Why didn't you do anything, Frost?"

"Because of you!" She shouts unexpectedly, making him stumble. "You keep telling me to stop killing and the one time I stop you're going to belittle me for it?"

Silence surrounds them like a blanket being smothered over the scene. Flash resumes his cleaning, and by the time he's done and the wound is wrapped and the kit is put away he's lifting her gently into his arms. Within the next moment he zips them into their bedroom and Killer Frost finds herself underneath him on the bed.

"Here?" She questions, astounded because they've never crossed this threshold before. That motel was their place. He kisses her on the lips, and then trails a few down her neck, stopping at the top of her clothing.

"I'm sorry. I'm sorry." He kisses her on the lips again, more gentle than he ever has. "Thank you for not killing. I'm so happy you didn't kill."

"Are you really?" She asks, as his hands go under her top.

He nods against her, and she scoffs. But then he does something that makes her heart pound. His hands fiddle under her clothing for a moment before going down and finding the helm of her shirt, tugging upwards a little. This is the line they don't cross. They've never gone all the way and had sex. But is this what he wants? What she wants?

"Flash." It's a question that comes out as a statement.

He brings his head up from her chest, and God, he looks as handsome as ever with his mask down and suit on, she thinks. Of course he looks good without the suit too, but he's the Flash, of course he looks good either way.

"Frost." He accounts, breaking her from her thoughts.

She rests a hand on the emblem of his suit, tracing the lightning bolt slowly. By the time she reaches the bottom, his hand is over-top hers. "Do you want this?" She mumbles, and he smiles.

"Yeah. Do you?"

She says yes, and they have one hell of a night.

She stops killing one day and runs away with him the next.

It's not going to be forever, because he's one of Central City's heroes and Joe's getting older each day and Wally needs a good influence in his life as Kid Flash. It's more like a mini-vacation, a little runaway to Starling City for the weekend.

They rent a nice hotel and go to nice dinners, and it's easy for her to use a blonde wig just to hide her hair so she's doesn't get arrested halfway through dessert. They live and they officially date and everything's okay.

They're sitting in his apartment a few months later, watching an old movie. Frost is in his lap, decked out in one of his too-big shirts while he's in nothing but thin sweatpants. All of a sudden she turns and kisses him, unannounced. He smiles and accepts, but she pulls back before things get too crazy. "I love you," she whispers against his lips. He chuckles, kissing her crudely (because their kissing seems to always be that way) but lovingly.

"You love me or the suit?"

She shrugs, "Well the suit helps."

He laughs again, and the sound rumbles through his chest, cavernous and real. "Hard to tell the difference sometimes, on if you love me or the suit more," he quips, and she smiles because it feels like they're back in their twenties and they're fresh heroes ready to take on the world again. "I love you too." He then says, and her heart seems to finally, finally, start to unfreeze.