There's a chill in the air at S.T.A.R. Labs on Tuesday night's "The Flash," as Caitlin Snow (Danielle Panabaker) struggles to keep her villainous side -- Killer Frost -- at bay.
After using her developing metahuman abilities to save Barry Allen, Caitlin's icy powers start to take over (just like her mother, Dr. Tanhaueser, predicted), pushing her toward becoming Killer Frost.
"[I] think that these powers are a little bit like a drug for her and I think she becomes addicted to them," Danielle Panabaker said, when AccessHollywood.com asked the actress what it is about the powers that makes her character turn evil. "And I think there is an element of it that feels so good to her, even though on another level she does know that what she's doing is wrong."
Killer Frost was briefly introduced at the end of Season 1, and was featured more prominently in several scenes on Earth 2 in the second season.
Asked if she learned early on in Season 3 that the character was returning, Danielle said she wasn't told right away, but was thrilled when she found out.
"They've released some photos – there's a new Killer Frost outfit, and I didn't know that that was happening until I got called for a fitting," she said. "It's something that we had talked about and I thought that there was a moment maybe at the end of Season 2 where it might happen and then it didn't, so I was always just crossing my fingers waiting to read each script."
With her powers taking root, in Tuesday's episode Caitlin Snow goes on the hunt for Dr. Alchemy. But, as for why exactly, Danielle could only confirm that it will be explained in the episode.
Her character will also kidnap Julian (Tom Felton) in the episode.
To try and help their friend return to normal, the team will get involved.
In one scene from the trailer, Barry Allen (Grant Gustin) tries to appeal to the goodness inside his pal to get her to come out of her frosty shell.
"I think he cares about Caitlin and he wants to help her with whatever's going on with her," Danielle said, when asked to describe the Caitlin/Barry interactions in Tuesday's episode. "I mean, obviously, based on her explosion in Episode 6, she's struggling and having a hard time and it wasn't her decision to tell the team. She wasn't ready. So, he, I think, is trying to look out for her and take care of her, and hopefully, help her through this difficult time."
Kevin Smith stepped behind the lens to direct Tuesday's new episode.
"He's just a joy to have around," Danielle said of the director.
The actress said she was thrilled when she found out Kevin was directing "Killer Frost."
"I didn't get to work with Kevin very much when he came on our show last season, so I was excited just to get to work with him, and on top of that, to have someone who is such an expert in all things comic book sort of guiding me through this incredible episode was really such a gift," she said.
"The Flash" continues Tuesday at 8/7 on The CW.
