frost, but make it killer

I got the good side of you
Sent it out into the blue
The people danced to the sound of your heart
The world sang along to it falling apart

— "The Good Side," Troye Sivan

Caitlin returned to Central City quietly, without fanfare. It was good to be reunited with her mom, even under these circumstances, but her mother's parting words haunted her: I'm sorry, honey. But the more you use your powers, the stronger they'll get.

While Caitlin didn't mind having superpowers, she did mind having zero control over them. And she definitely did mind have a killer alter-ego who had a history of being a conniving bitch.

How was she going to break this to Barry?

With a sigh, she unlocked her front door — and stopped short. Barry was there — or rather, he was flashing around doing god knows what, because all Caitlin could see were red flashes of lightning. "Baaaaarrrry?" she called questioningly.

The red lightning stopped abruptly and Barry somersaulted at her feet, seemingly off-balance. "Heeeey, Caitlin," he said in return, looking sheepish.

"Are you okay?"

"Yeah. I was just pacing. And stress-cleaning. But like, mostly pacing."

She gave him a look.

"Hey! I was worried about you, Cait," he said honestly.

"Barry," Caitlin said slowly, not quite able to meet his eyes. "We need to talk."

"Talk? Uhhh, heh, yeah, sure. What is this talk about? That phrase really never does precede good news. Look, if this is about me being here while you were gone, I'm sorry. I just really missed you and —"

"Barry."

"Sorry," he said again.

"Come, sit," she said, sitting down on her wide couch and patting the space next to her, sounding more confident than she felt. "I —" she swallowed. "I have a confession to make."

For once, Barry kept his mouth shut and looked at her, his gray-green eyes sharpening with curiosity. And a little apprehension.

"I'm a meta." Caitlin let out a long exhale. "It seems that when you created Flashpoint, my powers started to activate. She's inside me — Killer Frost."

Barry took her hand in his, looking at her trustingly. "Cait…"

"I'm sorry I didn't tell you sooner. I was trying to figure it out on my own; you had so much on your plate. And my mom — I thought my mom could help. She's pretty famous for her work on cryo-genetics, but she said that the more I use my powers, the stronger they get. I don't really know what to do, Barry."

"Cait, what are you afraid of?" he asked softly.

"I'm afraid of losing control. Of becoming her. Killer Frost. Of hurting someone."

"You remember what I said to Frankie?"

"You said… you said that you'd always be there for her if she needed it. That she had good inside her. That if Magenta came out, she could fight her. She was strong enough."

Barry nodded. "The same applies to you. You're strong enough, Cait. You're one of the strongest people I know. And one of the kindest, smartest, most beautiful people I know. With the biggest heart. So if anyone can maintain control over Killer Frost, you can."

"Thanks, Barry," Caitlin said, with a little sniffle. "But I think you win the Golden Globe for the Biggest Heart."

"Heh," he said, turning a little pink. He hid his embarrassment with a kiss. "Cait, I mean it though. I'm always here for you. I'll always be here for you. No matter how busy we get or how big the problem is — especially if it's a big problem." He squeezed her hand tighter.

"Thanks, Barry," she said again, pulling him in close for a hug. "So… wanna show me how much you missed me?" she asked, quirking an eyebrow and looking toward her bedroom.

Barry didn't respond. He simply scooped her up, bridal style, and flashed them to said bedroom.

S.T.A.R. Labs

"Cait. Thank you for using your powers… I know what that meant to you," Barry said, looking much refreshed in a flannel shirt and combed back hair.

Caitlin turned from Cisco, who was complaining about migraines and making a mess out of the gurney. "I didn't do anything," she said, shrugging it off.

"Well, you saved my life."

"You've saved mine plenty of times," she replied.

But Barry knew she was worried beneath her calm smile. He saw the hesitation as she took the power dampening cuffs off and shot an ice blast at Savitar. Even from the ground, gasping for breath and absolutely freezing, he could see her pause for a moment, staring at her hands in wonder? disbelief? then up at the dark night sky, as if thanking the stars that she maintained control over both her powers and her alter-ego.

Caitlin didn't hesitate often, not when it came to his life, so he knew what a big deal it was for her.

But she would never admit it. "I'm gonna… go check on Wally," she said softly, turning and leaving. She needed time to think. It felt like Frost was there, right underneath her skin, laughing in her head, her scornful tone an undercurrent in all of Caitlin's thoughts. It itched. But in a strange way, Caitlin was a little comforted knowing that she wasn't alone.

"Okay," Barry said in an equally soft tone and smiled at her retreating figure.

Handsome boy over there really likes you, Frost said, as Caitlin's eyes flashed ice blue.

Caitlin gasped but continued walking, praying that no one else saw what had just happened.

You know, there's a real easy way to solve this, Frost said as Caitlin drove home.

Caitlin ignored her and turned the radio up.

I know you can hear me, Caity. Also, can you please change the station? All these sappy love songs are making me want to freeze everyone to death. Plus, who even listens to the radio anymore? How did I get trapped in a grandma's body?

Caitlin reached for the volume knob to turn it up, only to find it frozen.

"Frost!" she shouted in frustration. "Stop. Ruining. My. Life!"

Oh, Caity. I'm not ruining your life. I'm helping you become great.

"Riiight. And like… evil, right?"

Frost sounded hurt. I'm not evil.

"Then why is your name Killer Frost?"

Caitlin could almost feel Frost shrug. Unclear. Probably because of my killer good looks, honestly.

"Ok, Frost. I'm going to give you one chance before we walk into my apartment and act all normal around Barry so he doesn't worry. How can we help Wally?"

Use your powers on the guy they caught and are interrogating. He knows who Alchemy is. Find Alchemy, bring them all down. This guy has seen Savitar, has seen Alchemy. He's not scared of what cops will do to him during interrogation. But he will be scared of a meta.

"I can't hurt him, Frost."

Let me do the dirty work for you, Caity. Frost smiled, and it felt like ice was seeping through her veins.

Caitlin felt a little powerful and very powerless at the same time. "Do not hurt him, Frost."

I'll try, Caity. Just for you. But you'll thank me later, no matter what.

And for an evening Caitlin and Barry were able to watch a movie (anything but Frozen, please, Caitlin had begged), eat dinner (Caitlin cooked this time — it took her mind off things and finally shut Frost up), and snuggle in bed before passing out (Barry had started snoring during the movie, to be honest. Caitlin supposed getting hauled around Central City by a speedster who proclaimed he was a god really did a number on your energy levels). As she drifted off to sleep, nestling cozily into the crook of Barry's arm, she felt Frost almost purr in delight as well.

What? Frost said, her voice echoing as Caitlin's eyelids grew heavy. He's nice to be around.

CCPD

Frost was having a lot of fun. She was out to play, and she had had enough of this sniveling man's proclamation that he "served the dark lord, Savitar." Like, come on. What was this, some nerdy video game?

Lords and gods and monsters. If anything… "You should fear me," she hissed, eyes lighting up and frost seeping out of her hands. She smiled.

As she walked away, freezing the door shut behind her, she ignored the shouts of the men stuck inside. "Don't worry, Caity, she muttered under her breath. "They'll figure it out. Not cold enough to kill them. It's just like… extended cryotherapy. It'll help them burn a few extra calories."

"Excuse me!" a British voice called from behind her.

Ugh. She spun around and found a scraggly blonde man looking at her. "Hm. I guess you're coming with me."

S.T.A.R. Labs

"Huh?" Joe said as he walked in, seeing Wally still cocooned. "Caitlin told me Wally was out…"

"I didn't even see her leave," Iris said, confused.

Oh no, Barry thought, and flashed to CCPD.

"Just the man I wanted to see," Detective Patterson said, loading his gun.

"I — what?"

"Your little friend's in trouble."

"My f—?"

"A female meta-human kidnapped Julian Albert. Look familiar?"

"No…" Barry trailed off as he looked at the security footage.

"Well, she's smart. Took out all the security cams before she did anything. But don't worry, we'll get her," the detective said confidently, cocking his gun and leaving.

Barry stood over the monitor, watching as Caitlin frosted the cams over. "What are you doing?" he whispered. "What are you doing, Cait?"

He headed back to S.T.A.R. Labs, deeply worried.

"What about Savitar?" Joe asked.

"No, we have to find Caitlin first. Then we can find Savitar." Barry said, a little desperately. They had to find Caitin before CCPD and their SWAT team did.

But H.R. served kinda helpful, albeit annoying (those drumsticks!). They managed to track down Caitlin and Julian, and Barry flashed off immediately, mumbling something about getting to them first.

Le's Frozen Foods Warehouse

"What part of I'll freeze you to death did you not understand!?" Frost shrieked as she turned back around, realizing that Julian had messaged CCPD while she had her back turned, warring with Caity over the ethics of it all.

She raised a hand. This annoying man with the annoying accent and a desperate need of a haircut was going to die. Sorry, Caity, she said, without even a little remorse.

"No! You can't!" Barry flashed in front of Julian, stopping Frost mid-freeze.

"I have to."

"No, Cait. You don't want to hurt anyone."

"Yes, she does! She wants to hurt people!" Julian shouted from behind him.

"I don't want to hurt you, Cait," Barry said.

"No! Knock her out!" Julian egged.

God, he grows more insufferable each day, Barry thought, and smacked his arm back into Julian's head, effectively knocking him out.

"At least you shut him up, Flash," Frost said sweetly. "I never thought he would."

"Caitlin," Barry said softly.

"Leave me alone!"

"What're you doing?"

"I have to find Alchemy!"

"We will find him. Together."

"No! You don't understand. I don't want to lock him up. I need him to help me," she said, gesturing wildly.

"Help you what?" Barry asked, not understanding.

"I need him to get rid of my powers!" Caitlin burst out.

Barry was stunned into silence. Iris, hearing the whole conversation over Barry's comms, shook her head sadly. "Oh, Caitlin…" she whispered.

"I don't know that it works that way," Barry said, keeping his voice soft and gentle.

"You don't know that it can't!"

"I know that I love you, and we will do anything we can to help you. You and I… we've been through too much together to let each other down now. Please. Let me help you." This was Caitlin, Barry was sure of it. He was beginning to tell (other than the eye color change… which to be honest, he found a little scary but also a little hot) when it was Caitlin and when it was Frost.

Caitlin looked like she wanted to run into his arms, but then her eyes flashed blue. "Like you helped your mother?" she asked cruelly. "Or Wally? Or me?"

"Caitlin…" Barry said, hurt.

"You keep messing with people's lives, and we're left to pick up the pieces of your mistakes. Some things you can't fix once they break. Like you tried to fix Cisco's family? That's right, Cisco. Dante was alive in the other timeline. When Barry fixed everything, Dante died. Barry is the reason your brother is dead," Frost spat.

Frost's words stung more than any ice dagger she could've thrown at him. The secret about Dante was something Barry had told only Caitlin, and for her to use it against him like that… he knew that this wasn't Caitlin, not really, but his heart broke a little at seeing the woman he loved rub salt in his wounds and stomp on his already heavy conscience.

Words mattered.

Guns cocked and Patterson's voice shouted, "Albert's down! Shoot her!"

Without even thinking, Barry picked Caitlin (Frost?) up and flashed her to safety. She gasped as he set her down behind a pallet, forming an ice dagger in her hand.

Barry screamed as it made contact. "That severed your triceps surae. Even with your healing abilities, it'll take four hours to regenerate," she said, sounding like the Dr. Snow he knew. But like… uncaring. "Don't follow me," she finished emphatically as Barry groaned in pain.

"Caitlin!" he reached out for her, on his knees like a man hoping desperately for salvation.

His hands scrabbled at thin air. She was gone, and Barry hurt in more places than one. Even after he pulled out the ice dagger, blood coating more than four inches of it, his heart felt the most broken of all.

S.T.A.R. Labs

"How much does it hurt?" Iris breathed.

"As much as I deserve," Barry replied. He was unused to being treated by anyone other than Caitlin. He missed her steady surgeon's hands patching up his numerous wounds, missed her concerned face being the first thing he saw when he woke, missed the way her teeth tugged at her lower lip when something was bothering her, missed her kind eyes and calming presence.

At least Iris knew enough to clean and bandage his wound. Iris opened her mouth to say something, but –

"They took Julian to County Hospital. He's still out cold," Joe said, walking up. "How hard did you hit him?"

"I don't know. I didn't mean to knock him out…" Barry winced, pulling his shoe onto his injured leg. Then he shrugged, not at all sorry. "Or maybe I did."

He limped a little as he got off the bed, making a beeline for his friend. "Cisco! Hey man… what Caitlin said…" he trailed off as he saw the man in question stare blanking into the distance, his shoulders slumped and his hair a little unkempt. Barry hadn't seen Cisco that despondent since… well, maybe ever.

"Was she lying?" Cisco interrupted, not meeting Barry's gaze.

There was a long silence.

Cisco turned around to find his best friend staring at him, shell-shocked. "No… uh… I'm sorry," Barry said, at a loss for words.

Iris watched the two men have this awkward conversation and she couldn't help but walk closer. Partly to listen, but mostly because her heart hurt for Barry. And for Caitlin. And for Cisco. For all of them really — they had been through so much.

"You're… sorry?" Cisco said incredulously. "That you killed my brother?" He walked up to Barry, tears shining in his eyes. "'Cause he was here. Until you created Flashpoint." He poked an accusatory finger into Barry's chest. "Until you did this." He emphasized that last statement with a shove, effectively sending his lanky friend back a few steps.

Iris bit her lip. Should she intervene?

"I know, man."

"I don't even know how to feel right now!" The tears in Cisco's eyes were threatening to overflow. "All that I know is Caitlin is out there, and we need to find her." He looked up at Barry. "Can we do that?"

"Yeah," Barry said, his gaze never breaking from Cisco's. "Yeah," he repeated, nodding.

If there was anything that would bring these two together again, Iris thought, it would be their love for Caitlin. I hope she's okay.

As the team headed out to the two addresses Julian had found, Barry couldn't help himself from saying, "Cisco. If you find her…"

Cisco turned, his eyes dark and flat. "I won't call you. You've done enough."

Barry looked down and resigned himself to being benched, to his girlfriend gone missing, and to one of his best friends hating him.

If he was being honest, he hated himself a little right now too.

A heavy silence hung in S.T.A.R. Labs. Iris had grown up with Barry and his moods — sullen, self-deprecating, contemplative, ecstatic, content, light-hearted, all of it — and knew when to keep quiet.

So she perched on the desk, watching him. He watched the screens, waiting for any sign of Cailtin.

Beep beep beep.

"What's that?" Iris asked, hopping off the desk.

Barry rushed to the far monitor. "It's the satellite. It's programmed to track rapid temperature decelerations. That's the house Cisco is watching."

And before Iris could finish saying, "Oh god," Barry was off.

She sighed and resumed her perch on the desk. It was going to be a long night.

16 Hawthorne Ave, Central City

Rain had started to pour. It was soft at first, a light mist in the dark night, but as the time ticked on, it began to pound a steady staccato on the pavement.

2:04AM read the red numbers on the clock in the house on Hawthorne. Normally Caitlin would be sleeping, but she and Frost had some answers to get.

That was, before Cisco came barging in.

She threw icicles at him with deadly accuracy. The last one would've gotten him, had she not been distracted by a sudden hiss of red lightning streaking down the block. He always finds you, Caity, she thought to her counterpart.

The rain was working to her advantage. Hello, a whole new world... of ice. She smirked as Barry slid to a stop at her feet. Speed and cold did not play well together, it seemed. "How's the leg?" she asked, raising an eyebrow.

He groaned and flung a long arm out, tripping her. She landed on the ground beside him with a thunk!, both of them breathless and staring at the dripping night sky.

"That was cold, Flash," she said. "But this is colder." She launched herself off the concrete and straddled him, planting a long kiss on his still-panting lips. It was like reverse-CPR, almost — Frost was simultaneously drawing the warmth out of him and breathing cold air into his lungs. She deepened the kiss as Barry began to turn blue. He made no move to resist her… though she supposed he was pretty much an ice sculpture by now.

Kinda like in Frozen, she thought wryly, before a twin blast of vibe power blasted her into the windshield of a parked car.

"Start vibrating. It'll warm you up," Cisco said to Barry as he took off after Caitlin.

Barry did as he told. As his cells began to generate more heat, he rolled to his side and stared after his two friends helplessly. What're you doing, Cait? he thought again. What're you doing?

S.T.A.R. Labs

Caitlin woke in a very familiar, very padded cell, feeling quite like a zoo animal. She groaned and pulled herself into a seated position, glaring daggers at the crowd gathered in front of the glass. "Whew. Guess I just needed a little sleep. Thanks guys! I'm feeling a lot better now. You can let me out. Don't worry, I'm not gonna hurt anybody."

She looked expectantly at Team Flash. No one said a word. No one made a move.

"Hmph. I guess you're all smarter than I thought." She shrugged. "You know, that was some blast there, Vibe Boy. It kinda hurt."

"I didn't want to hurt you," Cisco said sadly.

"You're pathetic." His face fell.

"Alchemy can't help you," Barry interjected before Cisco could dwell too much on what Caitlin was saying. "But we can." He fidgeted, rubbing thumb and forefinger against each other over and over again, wishing it were Caitlin's skin he was touching instead.

"Ohh… like you promised Ronnie?" she spat. "You know, for a hero, Flash, you sure do let a lot of people around you die."

Barry looked down and kept his gaze down as he replied, "This isn't you talking. It's the powers. They're messing with your mind." He finally met her eyes. "You're sick."

"I'm broken, Barry," she said, her bright blue eyes boring into his weary green ones. "But what do you care?"

"I care, Caitlin, I love you!" he burst out.

She ignored him. "I'll tell you what. You let me go, and I'll leave you to your sad, miserable lives."

"No. We're not abandoning you."

"You did this to me!" Caitlin hissed, and that was the final straw. Barry closed the gate, leaving her in perpetual darkness.

Alone.

"Do you have any idea how we can reverse this? How can we get Caitlin back?" Barry asked Cisco, an edge of desperation bleeding into his voice.

Cisco blinked away unshed tears. "It's just like what Caitlin said: sometimes when things get broken, they can't get fixed." Cisco walked away, leaving Barry with his thoughts.

Alone.