Tonight's episode of The Flash saw the team trying yet again to stop Clifford DeVoe from enacting his chilling plans for humanity and, in the process, made a major change to one character's established origin.
Spoiler's for tonight's episode of The Flash, "Think Fast," below.
When the team realizes that there are a mere twelve hours away from DeVoe/The Thinker (Neil Sandilands) successfully carrying out his Enlightenment, Cisco (Carlos Valdes) and Caitlin (Danielle Panabaker) come up with an interesting plan: enter Flashtime with Barry (Grant Gustin) by having him transfer a bit of his speed to them. This would allow the trio to work together to stop DeVoe by effectively being three places at the same time. They quickly start to train, but early on Caitlin has a mishap that results in her having a fragment of a childhood memory.
While Caitlin is able to continue training and be part of the mission, this unfamiliar memory troubles her so she has Cisco vibe her into the memory. It seems straightforward enough, though understandably traumatic. Young Caitlin has been in a bicycle accident, one that involved a car and while she's okay, we hear her father trying to keep her calm. Her hand reaches out and grabs the broken mirror from the car and her reflection is a shock. There, in the mirror, is a young Killer Frost.
Killer Frost has been with Caitlin presumably her whole life, meaning that Caitlin's powers were never connected to the particle accelerator accident that granted Barry his powers. Whatever brand of metahuman Caitlin is? She's completely different than anything the show has explored before.
This is a huge change, not just to Caitlin's story but to the Arrowverse in general. As we've seen previously, Team Flash has been able to tie every single meta they encounter to the explosion and, in this season, to the dark matter released when Barry emerged from the Speed Force. This information has arguably helped the team strategize and deal with each threat, but now we know that not every powered individual in the universe is a metahuman the way we know it. With Killer Frost being present even when Caitlin is a child, it suggests that some metas didn't need dark matter to be created.
That explains why, even though DeVoe took away Caitlin's Killer Frost powers, the anti-heroine still exists somewhere inside Caitlin. It also opens the door to some very interesting possibilities. It means that the Arrowverse could see the introduction of metahumans with a history like that of Black Lightning. On Black Lightning, Jefferson Pierce gained his metahuman powers as part of government-sanctioned experiment in the form of a vaccine, no dark matter required. This possibility is particularly interesting considering that we've met Caitlin's mom, Dr. Carla Tannhauser, a biomedical engineer.
Killer Frost emerging when Caitlin was a child also has another, Black Lightning-like implication. It could mean that some metahumans are born, not made. On Black Lightning, both of Jefferson's daughters inherited their metahuman abilities. If Caitlin was always Killer Frost, it may very well mean that Joe (Jesse L. Martin) and Cecile's (Danielle Nicolet) baby could be born with metahuman powers. It also might explain Cecile's pregnancy telepathy -- which we saw get even crazier tonight.
It also might just lend a little more credence to fan theories that whoever Mystery Girl is, she's related to Barry. We saw last week that she's a speedster in her own right. Now there's a possibility that she got those powers genetically.
What do you think about Killer Frost's new origin story? Let us know your thoughts in comments!