Watch: Ella Purnell thriller 'Sweetpea' gets trailer, Oct. premiere date

Sept. 19 (UPI) -- Starz is teasing the release of the new series Sweetpea.

The network shared a trailer and October premiere date for the show Thursday.

Sweetpea is a new thriller starring Fallout and Yellowjackets actress Ella Purnell as Rhiannon Lewis, "a quiet wallflower who develops a vengeful and intoxicatingly liberating taste for murder."

"Rhiannon Lewis doesn't make much of an impression -- 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. Then everything in her life turns upside down. Rhiannon is pushed over the edge and loses control. Suddenly the wallflower is gone, and in its place is a young woman capable of anything," an official synopsis reads.

The trailer shows Purnell's Rihannon turn into a killer who seeks revenge on her high school bully and others who have wronged her.

Nic?le Lecky, Jon Pointing, Calam Lynch, Leah Harvey, Jeremy Swift and Dustin Demri-Burns also star.

Sweetpea is based on the C.J. Skuse novel of the same name. The series is produced by See-Saw Films and Fanboy in association with Sky Studios, with Ella Jones as director.

Season 1 will consist of six episodes and premiere Oct. 10 at midnight on the Starz app and at 8 p.m. EDT on Starz. Subsequent episodes will be released Fridays.