One of the subplots of the current season of the Flash has been Caitlin Snow (Danielle Panabaker) trying to fight of the Killer Frost persona even though her friends keep finding reasons for her to use her powers. Each time she uses her powers, she seems to slip further and further down the rabbit hole. But there is also more going on here than we've seen. Cisco Ramon actor Carlos Valdes told EW.com:
Caitlin has some secrets of her own that are going to come to light and are going to change not just the dynamic of the team, but also her own feelings about her dynamic within the team. It all comes to a head.
Flash airs Tuesdays at 8 PM on the CW.