Ella Purnell Plays an Unassuming Serial Killer

Ella Purnell plays a wallflower-turned-murderer in the official trailer for Sky and Starz‘s thriller series “Sweetpea.”

The “Yellowjackets” and “Fallout” breakout stars as Rhiannon Lewis, a young woman who doesn’t particularly make an impression, in the six-part show based on C.J. Skuse’s novel of the same name.

“People walk past her in the street without a second glance. She’s continually overlooked for a promotion at work, the guy she likes won’t commit, and her dad is really, really sick. So far, so shit,” the show’s official synopis reads. “Then everything in her life is turned upside down, and Rhiannon is pushed over the edge. She snaps. Suddenly the wallflower is gone, and in its place is a young woman capable of anything… Rhiannon’s life transforms as she steps into a new, intoxicating power, but can she keep her killer secret?”

Alongside Purnell, “Sweetpea’s” ensemble cast includes Nicôle Lecky (“Mood,” “Sense8”) as Julia, Jon Pointing (“Big Boys,” “Smothered”) as Craig, Calam Lynch (“Bridgerton”) as AJ, Leah Harvey (“Foundation”) as Marina, Jeremy Swift (“Ted Lasso”) as Norman and Dustin Demri-Burns (“Slow Horses”) as Jeff.

“Sweetpea” is produced by “Slow Horses” and “Heartstopper” banner See-Saw Films and Fanboy in association with Sky Studios. The series was written by Kirstie Swain (“Pure”) alongside Krissie Ducker (“Killing Eve,”) Laura Jayne Tunbridge and Selina Lim (“Sex Education,” “Hanna”). Ella Jones (“The Baby,” “Back to Life”) serves as director. Purnell, Swain and Jones executive produce alongside Sky Studios commissioning editor Manpreet Dosanjh, Patrick Walters for Fanboy and Helen Gregory, Iain Canning and Emile Sherman for See-Saw. Zorana Piggott serves as series producer and NBCUniversal Global TV Distribution handle international sales of the series on behalf of Sky Studios.

The series will premiere Oct. 10 on Sky and streaming service Now in the U.K. and Starz in the U.S.

Watch the full trailer for “Sweetpea” below.