Caitlin (Danielle Panabaker) is finally telling Cisco (Carlos Valdes) that she’s developing powers similar to her Earth-2 doppelgänger, Killer Frost, in tonight’s episode of “The Flash.”

In a sneak peek for Season 3, episode 6, titled “Shade,” Caitlin freezes a glass of water with her bare hands in front of Cisco to reveal that she, too, is a metahuman. “Surprise,” a not-so-thrilled Caitlin tells her close friend as she holds the frozen glass of water upside down. “It started a few months ago.”

“That’s why you went to see your mom to see if she can help you,” Cisco replies.

“But she can’t,” says Caitlin, before asking Cisco a favor. “I need you to vibe me in the future because I want to know if I become [Killer Frost].”

Although Cisco initially thinks that vibing her is unnecessary, he ends up granting Cailtin’s request after the latter confesses that she has a strong feeling that she may become Killer Frost in the near future. “Please I just need to know for sure,” Caitlin begs. “I need to know if I become evil, because if I do. I have to leave and never come back.”

When Cisco finally vibes her, he sees visions of her and him fighting each other. For some reason, however, Cisco doesn’t tell Caitlin about this. “I didn’t see anything. You’re fine,” he tells her instead.

In an interview with Entertainment Weekly last month, Panabaker explained why Caitlin didn’t immediately tell her friends that she’s developing the same powers as Killer Frost.

“After hearing [about], and briefly meeting, Killer Frost at the end of Season 2, I think she’s terrified that could be her future,” Panabaker said of her character. “She said to Cisco at the end of last season, ‘I’m scared, I don’t want to become her,’ as she was suffering from her PTSD after everything with Zoom [Teddy Sears]. It is something that she’s very afraid of and cognizant of and trying to avoid.”

The synopsis for next week’s episode, however, revealed that Caitlin is indeed becoming Killer Frost. According the episode summary, Caitlin’s inner Killer Frost is unleashed after she uses her powers to save Barry (Grant Gustin). And when her metahuman self completely takes over, she ends up battling Barry and Cisco, just like what the latter sees in his visions.

“The Flash” airs every Tuesday at 8 p.m. EST on The CW.

Danielle Panabaker as Killer Frost Caitlin (Danielle Panabaker) finally reveals to Cisco (Carlos Valdes) that she’s developing powers similar to her Earth-2 doppelgänger Killer Frost in a sneak peek for tonight’s episode of “The Flash.” Photo: The CW