When Caitlin Snow aka Killer Frost returns to S.T.A.R. Labs, she is not quite the same as she was before. She’s had time to figure out who she is, so she is not the same person that his friends once knew. She has had time to accept that she is both Killer Frost and Caitlin Snow and with it comes a change in her personality.

Season 3 recap

When we last saw Caitlin Snow (Danielle Panabaker) in the Season 3 finale, she was unsure of who she was. She accepted that she has this power that turns her into an evil metahuman. At the same time, she is also the kind and good-natured Dr.

Snow. However, she was still confused about her role in the world. Julian (Tom Felton) gave her the choice to get rid of her metahuman powers and be Caitlin forever. She declined to take the cure he made. Instead, she decided to take some time away from her friends to discover herself. As showrunner Todd Helbing tells IGN, Caitlin left to go deal with her problem on her own and “figure out exactly who she was and how to deal with this newfound person inside of her.”

What happens to Caitlin?

When Caitlin returns in “The FlashSeason 4, she has had time to figure out who she really is.

She has had time to accept that she cannot be Caitlin Snow or Killer Frost. Instead, she has to be both, so when she returns to her friends at S.T.A.R. Labs, she is a different person. “Her personality has slightly altered a little bit, so she's not the Caitlin we saw in Season 3 or the seasons before that,” showrunner Todd Helbing tells IGN.

However, before Caitlin resumes work at S.T.A.R. Labs, she finds work outside her comfort zone. One of the promotional images for the season 4 premiere, “The Flash Reborn,” shows Caitlin as a bartender. Cisco comes to visit her and perhaps convince her to return to the team.

Likewise, Caitlin dresses differently now. She incorporates a little of Killer Frost in her outfits, just like what we see in the Comic-Con trailer for Season 4 (jump to the 0:54 mark).

Interestingly, she has on the same shirt from the bar scene. Perhaps after her conversation with Cisco, she surprises everyone and returns to S.T.A.R. Labs.

Danielle Panabaker talks Killer Frost

Helbing’s interview comes after Danielle Panabaker assured that fans of Killer Frost and Caitlin Snow will not be disappointed. She also revealed that at the beginning of “The Flash” Season 4, her character is not part of Team Flash. It is likely that Caitlin appears in Episode 2, “Mixed Signals.”