Just when it seems like something good might happen for "Riverdale's" Cooper family, the end of "Chapter 8: The Outsiders" revealed Polly (Tiera Skovbye) choosing to live with the Blossom family rather than coming home. And it's something Betty (Lili Reinhart) and Alice (Mädchen Amick) are being forced to cope with.

"Betty's obviously very concerned for her sister," Reinhart tells Screener. "She doesn't want [Polly] to be pulled into this dark world that she believes are the Blossoms -- Betty is heartbroken that Polly chose the Blossoms, and she doesn't understand why. Betty's confused and she's heartbroken."

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Amick echoes the sentiment, adding, "Alice isn't happy. She's obviously devastated that Polly chose the Blossoms over here. It takes everything in her to not show up and bust down the door, and take everybody out, to get her daughter back."

As Reinhart explains though, it's ultimately Polly's decision to make. "If Polly's safe, and that's what she wants, then she knows she has to accept it," she says. "But Betty knows there's more to the story -- so she goes after that."

Whatever "more" there is to the story is the big question hanging over "Riverdale." While the trailer for the show's next episode, "La Grande Illusion," shows Polly very close to the Blossom family, perhaps there's something deeper happening here.

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So what is Polly up to? And will it bring us any closer to figuring out who killed the love of her life, Jason Blossom (Trevor Stines)?

"Maybe there's a reason [Alice] leaves Polly at the Blossoms," Amick teases. "I'm just saying!"

"Riverdale" airs Thursdays at 9 p.m. ET/PT on The CW.

Posted by:Chris E. Hayner

Chris E. Hayner is equal parts nerd, crazy person and coffee. He watches too much TV, knows more about pro wrestling than you do and remembers every single show from the TGIF lineup. You may have seen him as a pro-shark protester in "Sharknado 3." His eventual memoir will be called "You're Wrong, Here's Why..." TV words to live by: "I'm a firm believer that sometimes it's right to do the wrong thing."