Karen has checked out of Falling Skies' alien apocalypse, or at least that's what viewers were led to believe during last summer's finale.

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Despite this, Tom Mason's former girlfriend will be the catalyst for much of the fourth season's story line. While the exact nature of Karen's (Jess Schram) post-death role is unknown, it will most employ flashbacks to give a behind the scene's look at Karen's time with the Espheni and her involvement with baby Lexi (now played by Scarlett Byrne).

"I think she's forever going to be the reason for a lot of the things that happen on the show," explained Sarah Carter (Maggie), according to Buddy TV. "She's the reason for everything in the next season. For everything - us separating and coming back together and she has a lot to do with Scarlett Byrne's character."

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Falling Skies viewers are eager to find out more about the alien/human hybrid that is Lexi, and that interest will spike as the six year old continues to age at a distinctly non-human rate. A peek into Karen's past would be an opportune way in which to explain her life to the audience, even if it does continue to leave Tom Mason (Noah Wyle) and Co. in the dark.

Falling Skies will return to TNT on June 22. Click the video below to see a new preview.