Caitlin Snow’s transformation into her comic book alter ego Killer Frost was one of the most highly anticipated events on The Flash. It not only introduced a long awaited villain to Central City, but it provided one of the series’ most underused characters with a story of her own, one that – for once – had nothing to do with her romantic life.
However, Caitlin’s journey as Killer Frost has been somewhat convoluted. She’s gone from a key member of Team Flash to a villain to an anti-heroine, and almost everything in between. Her story has been pretty messy in places – The Flash hasn’t done the best job of explaining Killer Frost’s motivations or even how her connection to Caitlin functions — but at the end of the day The Flash is ultimately giving us an incredibly powerful the story about a complex woman discovering herself and her powers for the first time.
Let’s take a look at Killer Frost’s journey over the last four seasons and what’s ahead for her in Season 5.
An Earth-2 Criminal
We first meet Killer Frost as Caitlin Snow’s metahuman doppelganger on Earth-2. She possesses cryokinetic abilities and has led a much harder life than the woman we know. This Caitlin flunked out of medical school, has a dead brother named Charlie and works as a criminal enforcer for the evil speedster Zoom. After the death of her husband – the Earth-2 version of Ronnie Raymond known as Deathstorm – she reluctantly joins forces with Team Flash. This version of Killer Frost is ultimately killed by Zoom once he successfully kidnaps Earth-1’s Caitlin.
Caitlin’s Earth-2 doppelganger is important because she represents our introduction to Killer Frost as a concept. From the outset, her character teases the possibility of change and growth, floating the idea on multiple occasions that Killer Frost has a heart and is capable of being more than a villain.
A Flashpoint Creation
Following the creation of the Flashpoint universe, Caitlin develops the same icy powers her Earth-2 alter ego displayed. These abilities manifest themselves whenever she is angry or otherwise loses control of her emotions. And each time she uses them, the more like Earth-2’s Killer Frost she becomes. (Complete with white hair and everything!)
For some inexplicable reason, The Flash never entirely explains why using her abilities affects Caitlin this way. But after using her powers to save Barry from yet another evil speedster named Savitar, Caitlin becomes Killer Frost completely, rampaging through Central City on a search for the mysterious Alchemy. Barry ultimately brings Caitlin back to herself by appealing to her compassionate nature.
A Villain’s Partner
After an attack by metahuman Abra Cadabra, the team needs to access Caitlin’s rapid healing abilities to save her life. But once Julian removes the necklace suppressing her meta powers, Killer Frost emerges. And it seems as though she may have taken over Caitlin for good.
Killer Frost joins forces with Savitar after he reveals himself as a future version of Barry Allen. Once again, The Flash isn’t clear about Killer Frost’s motivations – why she’s willing to help Savitar or what his promises of “becoming a god” mean. In the end, Killer Frost doubts his plan and ultimately can’t betray her friends. During the season’s final showdown, she switches sides, rescuing Cisco, attacking Savitar, and standing by as Barry and friends defeat Savitar for good.
Killer Frost ends Season 3 in a strange limbo. She’s no longer Caitlin, she says. But she’s not Killer Frost either. Still sporting her signature white hair, and she leaves Central City to find herself.
An Identity Crisis
Rather than a journey of self-discovery, however, Caitlin spends her summer working for black market metahuman dealer Amunet Black. Instead of figuring out how to accept – or co-exist with – her dark side, Caitlin suppresses it. With a little help from her friends, though, she eventually decides to try and live with Killer Frost, which basically means Frost shows up whenever Team Flash needs icy back-up.
Now, Killer Frost isn’t simply a darker facet of Caitlin’s personality, but a separate person entirely. The two just…happen to share a body. Somehow. Maybe? Killer Frost becomes less a part of Caitlin and more the “mean roommate” who occasionally takes over her life. And even though the two develop a tentative connection, it largely forms offscreen.
On the plus side: Caitlin and Killer Frost’s bizarre friendship, built on little more than post-its and hope, is surprisingly charming. Which is why Caitlin’s devastation over the sudden loss of Killer Frost – via an attack from The Thinker – feels so genuine. Her determination to bring her icy alter ego back is perhaps surprising, given her many attempts to suppress her abilities. But it’s also one of the first real moments of agency Caitlin’s had during this whole process, and a hopeful moment for the future of both characters.
A New Beginning
Season 4’s penultimate episode, “Think Fast,” reveals Caitlin has always carried Killer Frost within her, in her very DNA. This idea – that she’s been a metahuman since well before the particle accelerator explosion – is a shocking twist for the Arrowverse. What other kinds of metas might exist out there, waiting to be discovered?
More importantly, it’s an exciting development for Caitlin’s storyline. Thanks to the sudden resurfacing of a childhood memory, she sees herself as Frost after surviving a life-threatening accident. She hasn’t been possessed by a strange, foreign entity. Caitlin has always been Killer Frost. Somewhere.
However, thanks to The Thinker, Caitlin can no longer reach her icy alter ego or access her abilities. While Season 4 ended with no hint at how she’ll reconnect to her frosty side, it’s obvious she deeply wants to do so. And such a journey would provide Caitlin with something she’s yet to possess in this storyline: Agency.
Looking Ahead to Season 5
Throughout her various incarnations as Killer Frost – whether on Earth-2, after Flashpoint or following her near-death experience in Season 3 – Caitlin never had the chance to choose her own identity. In every version of her story, her powers come from external forces: The particle accelerator explosion, Barry’s time travel, the decision to remove her necklace. Here, her search for Killer Frost is solely Caitlin’s choice.
FANDOM caught up with Flash actress Danielle Panabaker at San Diego Comic-Con, who shared her thoughts on Caitlin’s upcoming journey with Killer Frost. “I’m excited in Season 5 to hopefully dive into their relationship a little more. Killer Frost disappeared and I feel like we didn’t really get to explore her origin story in Season 4. What are her origins and her motivations? We’ll get to answer that this season.”
As for the flashback she had in the Season 4 finale, we will find out who Thomas is and what exactly happened in that memory. “For sure that is the journey that Caitlin is going to go on this season. We are going to understand more about all these questions in her past and I’m excited for that. Her project this year is herself. As a doctor, that appeals to her. And she will seek out her mother for the answers to her childhood questions.”
Perhaps her quest will not just get her powers back, it will finally allow her to make some sort of peace with herself. After all, if Caitlin has always been Killer Frost, whether she knew it or not, couldn’t we someday see a version of her character who doesn’t switch between two personalities, but, instead, has integrated both? The idea of a truly meta-powered Caitlin, who must work to understand and control her own darkness to help others is fascinating and would make for some fantastic TV.
The Flash airs Tuesdays on The CW this Fall.