Having impressed with his direction of an episode during season two, it's no wonder The CW asked Kevin Smith to helm another one for The Flash's upcoming third season. While fans are undoubtedly looking forward to having him back behind the camera, it seems as if Smith himself is buzzing about the opportunity too – so much so, in his excitement, he appeared to leak the telling title of episode he is directing, Killer Frost, by mistake.

First spotted by Heroic Hollywood, Smith shared an image of his script for episode seven of the new series yesterday (14 September), making sure to cover the name with a pen. Captioning the shot, the 46-year-old wrote: "I start shooting my second episode of @CW_TheFlash today! Big thanks to @AJKreisberg & @GBerlanti for another run!" It all seemed innocent enough, however, the publication noted that if you carefully examine the top of the script, you can actually read the episode's title through the paper.

As fans of the show will already know, Killer Frost (played by Danielle Panabaker) was an ice-based supervillain, who appeared in a couple of episodes in the middle of the second season. She was the evil doppelganger of existing character Caitlin Snow (also Panabaker), who is a long-term ally of titular hero Barry Allen (Grant Gustin).

Her time on the series was short lived, though, as after the main characters travelled to Earth-2 (and discovered their dastardly counterparts in the parallel universe), Killer Frost was killed by Hunter Zolomon aka Zoom. Many fans assumed that would be the last they saw of her, but this new episode title suggests that might not be the case after all.

Alternatively, Killer Frost might just simply be a tease and actually focus instead on Snow. When she met Killer Frost in Earth-2, she became worried that she would end up turning to the dark side in the same way – perhaps the episode continues developing those concerns? Similarly, fans could finally see Snow evolve into a metahuman like Killer Frost, spurred on by tragic, previous events in the show.

"We've seen her be Killer Frost. We see her heart wants to grow cold, is how I can put it," Zoom actor Teddy Sears told E! News. "I'm not saying she becomes Killer Frost in life at all," Sears explained. "But we all know from seeing her doppelganger that she has that potential. She begins to internalize what she has to do next with this new information. Who will she become? How will she react?"

The Flash returns to small screens in the US on 4 October.

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