‘The Flash’ Season 3 Finale Hints At New Killer Frost, No Caitlin Snow In Season 4

"The Flash" Season 3 Finale hinted at the presence of more Killer Frost and possibly no Caitlin Snow in Season 4. Danielle Panabaker likewise teased that her character's metahuman persona remains, although executive producer Andrew Kreisberg teased at a new version of the character. 

"The Flash" Season 3 Finale confirmed that Caitlin Snow is gone, replaced by Killer Frost in Season 4. To recap, the episode gave Caitlin the opportunity to get rid of her metahuman powers following the success of Julian's cure. Cisco gave Killer Frost the cure and gave her time to decide what she wants to do with it.

Of course, viewers expected that she take the cure. However, "The Flash" Season 3 Finale saw Killer Frost return it to Cisco. Killer Frost basically confirmed that Caitlin is gone, which is why she chose to retain her evil persona. This means Killer Frost remains in Season 4 and Panabaker likewise hinted in her interview with Entertainment Weekly that Caitlin may never return.

 "I don't know if we'll even be able to see Caitlin again [in Season 4], but as you'll see in episode 21 ['The Flash' Season 3 Finale], it becomes clear that Caitlin Snow and Killer Frost do occupy the same body and that they have the same memories. I do think it will be difficult not only for Caitlin but all of team flash to reconcile Killer Frost's bad behavior under the guise of Caitlin Snow's face," Panabaker said.

According to Cartermatt, it is likely that Season 4 explores Killer Frost's journey to finding out who she really is. "The Flash" Season 3 Finale hinted that she could either be a hero or a villain.

Regardless, Kreisberg assured that Killer Frost is not going anywhere in Season 4. He also teased that the installment features a different version of the character. Perhaps this version of Killer Frost is one that shows empathy, as also hitned in "The Flash" Season 3 Finale.