"You'll see quite a bit [of Earth-2]" in upcoming episodes, Helbing told Entertainment Weekly. He also confirmed that fans will soon learn Killer Frost's fate; the report promises viewers will see her again.
At the conclusion of "Escape from Earth-2," Killer Frost made a difficult decision. Though she initially sold Team Flash out to Zoom, she quickly switched allegiances after that and helped them escape by burying Zoom under a mountain of ice. This gave Team Flash just enough time to make it back to the breach between worlds.
However, Killer Frost wasn't able to keep Zoom down long. Barry and Harrison Wells had a close encounter with the nefarious speedster just before they made it back to Earth-1. The episode doesn't reveal what happened to Killer Frost in the time in between. As Helbing says, though, it won't be a mystery for too much longer.