Archie Andrews is forever a changed man.

ET exclusively premieres a special Riverdale featurette with stars KJ Apa and Cole Sprouse, who dish on Archie's dark turn following his stint in juvie at the Leopold and Loeb Juvenile Detention Center.

"After the underground fighting and being in prison, a little bit of Archie's innocence is taken away," Apa, 21, says in the exclusive featurette, available with purchase of the Riverdale season three-season pass. "He's not the same kid from season one that you see who's trying to figure out what he wants to do with his life: is it music or is it football?" 

"Archie's hero journey is about maintaining his moral center within these otherwise terrifying situations," Sprouse, 26, explains. "And narratively, that's what he's coming to terms with -- either holding onto or losing -- across the season."

For Apa, it's been an exhilarating journey thus far on The CW drama, expressing his enthusiasm over getting to dive into the physical, emotional and dramatic side of Archie.

"The stakes are a little higher for him at the moment," he says. "For me as an actor, the material that I'm getting to play with at the moment is amazing. I'm so lucky to be able to sink my teeth into something that challenges me and that physically challenges, mentally challenges and emotionally changes me. And it's fun. The physical stuff is just fun; it's pretty much aIl I want to be doing at the moment."

Riverdale airs its fall finale Wednesday at 8 p.m. ET/PT on The CW. The Riverdale season three-season pass is now available to buy, with the full featurette available Thursday, Dec. 13 with purchase.

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