The Flash Showrunner Teases Danielle Panabaker's New Character (Exclusive)

Season 8 of The Flash had some major developments for Caitlin Snow (Danielle Panabaker), the biggest one being the loss of her sister, Frost (also Panabaker). The beloved hero was killed when she transformed herself into Hell Frost to take on Deathstorm (Robbie Amell) and while she did save the day, it cost her her life. Unable to cope, Caitlin worked with Frost's boyfriend Mark (Jon Cor) to try to bring Frost back, but at the end of the season, the cryo-pod Caitlin put herself in for the transformation malfunctioned and while someone came out, it was left ambiguous as to who that was. The Season 9 premiere of The Flash reveals who that person is — in part — and while we don't know everything yet, showrunner Eric Wallace tells ComicBook.com we're going to find out fast and they are integral to the rest of the season.

Warning: spoilers for the Season 9 premiere of The Flash, "Wednesday Ever After", beyond this point.

At the end of the episode, Barry responds to a call presumably from Caitlin at the breakroom at STAR Labs, but it's not Caitlin who he meets — nor is it Frost. It's someone else entirely and they are meeting Barry for the first time. While fans will certainly have their theories on who this is, Wallace says we will find out for sure next week.

"At the end of 902, you're going to learn who this character is, what her name is, her origin, and how she got here. But what you won't learn, and it's going to take all season long, is why is she here, and why now," Wallace said. "And the answer is, we could not defeat, we being Team Flash, Team Flash could not defeat the final big bad in a series finale without the help of this incredible new character that Danielle Panabaker is playing, the character who stepped out of the pod in the premiere."

Who Could this New Character Be?

In comics, there have been three people to have the mantle of Killer Frost — Crystal Frost, Louise Lincoln, and of course, Caitlin Snow. Crystal Frost or Louise Lincoln could both be possibilities. There have also been other versions of Frost on The Flash. There was the Killer Frost of Earth-2 and while technically that reality no longer exists, it could be something that The Flash draws on for this new character. There's also the possibility that we're getting someone called Khione — which is what Caitlin's father, Thomas Snow first called the dual personality that Caitlin began exhibiting after his experiments attempting to freeze the ALS gene.

But is Frost actually dead?

Whoever the new character is, Panabaker told us last year that Frost is really dead because it's something that she wanted to be real.

"This was actually something that Eric had pitched to me last summer," Panabaker said. "I think right around the time we were wrapping up Season 7, and he was throwing ideas around for Season 8. My biggest concern was that I didn't want it to be a fake out. I wanted it to be a real death. It didn't seem fair to have this be a tease. So, I've known the whole season."

The Flash airs Wednesdays at 8/7c on The CW.