After almost two seasons on the air, “The Flash” is finally letting one of its principal characters rise to her comic book ranks and become a brand new villain. When the CW series airs the first of its two-part episode, “Welcome to Earth-2,” the parallel dimension doppelganger of the hero’s best friend will appear with superpowers for the first time.

Caitlin Snow (Danielle Panabaker) has been with “The Flash” since the pilot episode in 2014. In that time, she’s developed the character into a sweet and quirky young scientist that’s hardened herself to the world of meta-humans after losing her husband, Ronnie Raymond (Robbie Amell), in a freak accident (twice). While he went on to become the superhero Firestorm, Caitlin remained as one of Team Flash’s few non-powered members. However, fans of the DC Comics world know the name Caitlin Snow in a very different context.

In both the show and comics, Snow is an extra-brilliant scientist working for S.T.A.R. Labs. When an arctic facility loses its primary researcher, Snow fills in. After she successfully gets things on track, her colleagues turn on her, revealing themselves to be working with H.I.V.E., which “Arrow” fans will note were introduced during Season 4. To escape, she exposes herself to a high-powered coolant system, forever infusing her body with ice. In the comic book, this endows her with powers that allow her to coat her body in ice, as well as generate frozen projectiles. After the accident, she finds herself constantly needing to absorb massive amounts of heat in order to quell her condition. That’s when she meets Firestorm and learns she can absorb his nuclear energy and temporarily cure herself.

In the show, Snow is just a friend to Barry Allen (Grant Gustin) but when he visits the parallel Earth-2 dimension, he finds that her doppelganger somehow got the powers of Killer Frost. In addition, she’s working with a villainous Ronnie Raymond in his Firestorm persona.

“Robbie is so wonderful, it’s so great to have him as a co-star to get to work with,” Panabaker told IGN about her upcoming role. “We had so much fun with the heightened everything of these guys. They’re passionately in love in a way that’s a little different than Caitlin and Ronnie were.”

“The Flash” Season 2, episode 13 airs Tuesday, Feb. 9 at 8 p.m. EST. Are you excited to see Killer Frost at last? Comment below or tweet your thoughts to @TylerMcCarthy.