The Flash: 4 predictions for the season 4 finale

2. Killer Frost will rise

Although Caitlin has never been best friends with her icy alter-ego, Killer Frost, the two have become somewhat closer this season. You would think that inhabiting the same body would make it incredibly hard to communicate with someone, but thanks to post-it notes and learning more about each other, Caitlin and Frost are more of a unit than ever before. Well, at least they were.

As we learned early on, Killer Frost would only rear her icy head when Caitlin felt threatened. But she was unable to take down DeVoe when he inhabited Ralph’s body. With a single word, the villain managed to force Killer Frost to revert back into Caitlin. While she has yet to resurface, Caitlin discovered that she still lives within her and the right trigger could force her to return.

But last week’s outing revealed that Killer Frost was much more a part of Caitlin than she thought. In fact, the ice queen existed when Caitlin was a child — long before the particle accelerator explosion. You can rest assured that this reveal will play into Caitlin’s story in the season finale. But more than that, it may lead to the return of Killer Frost. And if Caitlin can figure out how to trigger Frost’s return, this might give the team a clue as to how they could overcome DeVoe’s mind control. After all, DeVoe didn’t take her powers, he only made her think that he did.