Caitlin is still keeping her powers from Barry, Cisco and the rest of the team on The Flash , but in "Monster" she went looking for help from someone else: her mother. In light of her growing Killer Frost powers, Caitlin paid a visit to her estranged mother, Dr. Carla Tannhauser, to assess her new situation — mainly, how she can create ice with her hands. But, as Caitlin explored her powers on The Flash with her mother it became clear that she can't control her powers, and Killer Frost might be coming soon.
After accidentally freezing the water in her shower and finding a white streak in her hair, it seems that Caitlin is so desperate to get rid of, or at least gain control over, her powers that she'll do anything, even see her mom. Caitlin and her mother have been estranged for years, and going from an awkward reunion to medical testing isn't great for their relationship. As Dr. Tannhauser tested Caitlin's abilities, the mother daughter pair also got to finally face what drew them apart in the first place: the death of Caitlin's father. But, after Caitlin confronted her mother about being cold and taking refuge in her work after her father's death, she was ready to leave. Unfortunately, Dr. Tannhauser's pesky assistant, Nigel, didn't want to let a meta like Caitlin go. He tried to lock her in the lab — a decision that ended with Caitlin using her powers on his arm and getting so angry that her eyes turned grey. For a moment, it looked like Caitlin was going to kill Nigel.
Luckily, her mother interrupted them just in time and managed to talk Caitlin down. Still, it's clear Caitlin has no control once her emotions trigger her powers. And it might be getting worse. At the end of the episode, Caitlin received a message from her mother warning her not to use her powers "under any circumstances" as they will only grow stronger with use. Hearing this, Caitlin's powers took over and she ended up icing her desktop. If Caitlin can't learn to control her powers, Killer Frost might really be coming to Earth 1.
Images: Katie Yu/The CW; Giphy