Stranger Things' Shannon Purser Arrives in Riverdale With Episode 3

If authorities have been unable to solve the mystery of Barb Holland's disappearance, it's probably because they've been searching in the wrong place. The missing teen isn't in Hawkins, Indiana, or even the Upside Down, but in Riverdale.

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The CW has released the synopsis for the Feb. 9 episode of its new Archie Comics drama "Riverdale," which introduces "Stranger Things" alum Shannon Purser as classic character Ethel Muggs, aka Big Ethel. In the episode, "Chapter Three: Body Double," she teams with Camila Mendes' Veronica to expose some Riverdale High football players after rumors begin to circulate at the school about a "shame book."

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However, the central mystery of this "Twin Peaks"-esque take on the Archie Comics gang is the death of Jason Blossom, which casts a shadow over not-so-sunny Riverdale, where dark secrets lurk just beneath the surface. Here's the synopsis for "Chapter Three: Body Double":

THE GIRL WHO CRIED SHOTGUN — After new information surrounding Jason’s death comes to light, Cheryl (Madelaine Petsch) finds herself under a cloud of suspicion and forced to come clean about the last time she saw her brother. Meanwhile, Archie (KJ Apa) makes a tough decision that puts a major strain on his relationship with Miss Grundy (guest star Sarah Habel). Elsewhere, Betty (Lili Reinhart) decides to revive the school newspaper and asks for Jughead’s (Cole Sprouse) help in investigating Jason’s death, while Veronica (Camila Mendes) and Ethel (guest star Shannon Purser) work on exposing some of Riverdale High’s football players after rumors of a “shame book” begin to circulate. Finally, after getting grounded by his dad Fred (Luke Perry), Archie must figure out a way to make it to the Taste of Riverdale event where Josie (Ashleigh Murray) and the Pussycats will be performing a song he helped write.

Purser is expected to appear in at least three episodes of "Riverdale" this season. However, to the disappointment of many viewers, she won't be back for Season Two of "Stranger Things."

Premiering Thursday at 9 p.m. ET/PT on The CW, "Riverdale" stars K.J. Apa as Archie Andrews, Cole Sprouse as Jughead Jones, Camila Mendes as Veronica Lodge, Lili Reinhart as Betty Cooper, Madelaine Petsch as Cheryl Blossom, Ashleigh Murray as Josie McCoy, Casey Cott as Kevin Keller and Ross Butler as Reggie Mantle.

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