After their conversation that day, Barry began to act more like his old self. He began to include Caitlin and Cisco more in his life, which was nice, but at the same time they had to deal with Iris frowning in the background. It was feeling more and more like the old days when Iris would just hang out at S.T.A.R. instead of bossing everyone around. The focus was more on the science and research of stopping metas as well as studying their powers. It took a few days, but in the end they were able to pinpoint a location for the Duster.
"Are you sure this is going to work Cisco?" Barry asked as he, Nora and Caitlin stood in an abandoned scrapyard in Keystone. Cisco was back at the lab, monitoring everything, his powers still recovering from Cicada.
"The way Dr. Snow set up the gene therapy for him and Caitlin involves the use of heavy water. It's different than how regular heavy water is produced. Normal heavy water is a byproduct of nuclear power plants, but in this case, the organic matter that Caitlin produces when she uses her powers are even heavier. This causes her ice to be more resilient and harder to break than regular ice. If we can lure the Duster close enough, he should be able to pick up Caitlin with his senses and he would be trapped, lured by her pheromones."
Caitlin rolled her head on her neck, trying to loosen up. Yes, this was her plan, but that didn't mean it was a plan she wanted to go through with. She was the bait and the trap, all rolled into one. To make things more difficult for the meta they were trying to catch, Frost wore full leathers in the same material as Barry's suit. This outfit was black though, with silver and blue accents. She was covered from neck to toe, leaving her hands free. This was to reduce the surface area that could be affected by Duster.
"Are you ok Aunt Caitlin?" Nora asked as Barry paced back and forth, eyes darting back and forth between her father and unofficial aunt. Caitlin nodded and closed her eyes, falling back and letting Killer Frost take over. Opening now electric blue eyes she flexed her fingers and created a small ball of cryo nitrogen, baiting the trap.
"Let's catch a meta." The other half of her personality purred, ready for a fight.
"Nora and I will lead him to you." Barry reached over and touched her shoulder, brushing her hair back in the process. It was a very tender gesture, and one Caitlin was sure Nora hadn't missed. "Be careful Cait."
"I'll take good care of Caity Barry." Frost smirked, knowing it unsettled him when he was addressed by her. Both sides of her liked toying with him, teasing him. It was the only interaction she really enjoyed with him now that he's married. The occasional flirt here or there, but that was all. Both speedsters flashed away, leaving Caitlin and Frost alone.
"Too bad he's married to that thorn Iris. We could really burn the world down if we wanted. That's why Savitar and I made one hell of a team." Frost murmured in their mind.
"She is a bit of a bitch, isn't she?" Caitlin asked in return. "In the beginning she was just annoying, always wanting to hang around Barry once she realized he had powers. Over time she's just devolved into a real pain in the ass. Always in the way, never contributing anything to the team."
"Wow Caity girl." Frost sounded impressed. "Seems like I'm influencing you more than I realized."
"I'm going to be sad when you eventually fade away, but I love the fact that you are making me more confident in who I am and what I can do." Caitlin replied honestly.
"Don't worry Caity, I'll leave you all by best qualities." Frost smirked as the comm crackled to life.
"Heads up, here he comes." Cisco called and Frost focused, building the ball in her hands larger. They watched as a figure entered the other end of the scrapyard, and suddenly there was a tugging sensation all over her body. The meta was already pulling at the moisture in her body.
Frost grit her teeth and dug her heels in. The pull kept getting stronger as Duster came closer, face twisted into a grimace, his hands up and sucking at her. Frost held her hands far apart and let go of the bomb in her hands, letting it fly at the man approaching her. The man froze in his tracks, encased in ice. Cautiously Caitlin approached, not sure if they had succeeded or not. She reached out to the ice and found herself trapped, the meta still able to pull her moisture out of her, the ice around him melting into his body. His hand shot out, wrapping around her throat, ice falling away from them both.
Frost doubled down on pumping out the cold, straining to overload the meta. Icy fire burned in her veins, making her scream in pain. Slowly, slowly though she was making progress. The hand around her neck began to stiffen, skin turning a sick blue color. Her whole body began to burn as his slowly froze, the scream coming from her throat rising in pitch. They knew that they needed to do this alone; if Barry or Nora helped her, he would be able to pull from an alternate source of moisture.
From a distance Barry and Nora watched in fear and awe. Caitlin and Frost were glowing blue white in the fading sunlight, shining like a star. Tears streamed down the cheeks of everyone listening, and they could hear the faint sound of the monitors in the cortex beginning to ring. Yes, the meta was being defeated, but Caitlin was dying too, pumping her life force into the cold that fueled her powers. They both knew it too.
"Caitlin, I think this is going to be the end of me." Frost sounded winded and weak, voice thin. "There isn't going to be enough left of me to hang on."
"Please no, I don't think I can do this without you." Caitlin cried even as the meta in their hands continued to freeze.
"Dear Caity, you have always been more than capable of taking care of yourself. I have faith that you'll manage without me." Images of Barry flashed through their mind and Frost laughed gently.
"Don't give up on our love. Remember, the future isn't written in stone. You can change your stars." With a cool wisp, Killer Frost disappeared. With an anguished scream Caitlin let go, blasting everything she had at the Duster, disintegrating him into snow.
Sobbing Caitlin collapsed to the ground, mourning for the other half of her soul. Her sister, her best friend, her enemy. She seemed empty now, lost and adrift. She was so wrapped up in her grief that she never noticed Barry scoop her up and run her back to S.T.A.R. Labs.