Caitlin's (Danielle Panabaker) mysterious summer has been the topic of much speculation for The Flash fans, but now that we know what she and Killer Frost were up to during the hiatus, it's only opened up a dozen new questions.

While trying to wrestle control of her body back from Killer Frost over the summer, Caitlin decided to test out a new bit of tech that Amunet (Katee Sackhoff) — this week's dastardly villain — promised would put her securely in the driver's seat. The only cost? Killer Frost would have to work as Amunet's muscle during her black market deals. It makes sense, since Caitlin started losing control of Killer Frost again immediately after she left Amunet to be on Team Flash.

All of this became public knowledge on the night of Iris' (Candice Patton) bachelorette party, and the girls were left to fend for themselves while Barry (Grant Gustin) suffered some serious inebriation at Cisco's hands.

While Amunet seems like a kind of low-rent version of Magneto (and did you guys catch that Incredible Hulk reference too?), she was fierce enough to give even Killer Frost the heebie-jeebies. It will presumably be up to Barry to capture Amunet since Iris stepped in when Killer Frost was about to go in for the kill, but the decision to let her go does present an interesting question for us: Has Caitlin finally come to terms with Killer Frost, and vice versa? And if so, will she start suiting up to take down metas?

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The Flash has done a pretty good job of establishing that Caitlin and Killer Frost are two entirely different characters, but the more we see of Killer Frost, the more traces of Caitlin we notice within her. She may not be the cuddly type, but she's protective of Iris and the other girls, which makes us wonder if she hasn't absorbed some of Caitlin's fondness for the team. On the other end of the spectrum, Caitlin has obviously become more fierce thanks to Killer Frost's influence, which can only be a good thing if she's going to keep taking on metas.

Perhaps most importantly, we saw the first transformation of both parties' own free will this episode. Caitlin purposefully let Killer Frost out to deal with Amunet, and then later Killer Frost voluntarily gave control back to Caitlin. That kind of exchange has never happened before, which makes it kind of a big deal. There may still be a long way to go, but this could be the beginning of a symbiotic relationship between the two halves of Caitlin's personality.

The Flash airs Tuesdays at 8/7c on The CW.

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Danielle Panabaker, <em>The Flash</em>Danielle Panabaker, The Flash