The 'Fallout' star takes us behind-the-scenes of playing a sidelined receptionist who develops an intoxicatingly liberating taste for murder in the Starz dark comedy.

Despite her upcoming murderous portrayal, Ella Purnell struggled to stomach her latest role. As the British actress discussed her homicidal character Rhiannon Lewis in Sweetpea, premiering Oct. 10 on Starz and Sky, she admitted starring in the series did “take a toll” on her mentally.

While "Sweetpea" will be a streaming exclusive, Starz also has a linear TV channel. If you don't already have Starz on cable, you can pick it up as an add-on on several live TV streaming services, including Hulu, Sling TV, Fubo, YouTube TV, Philo, and DirecTV Stream.

Fallout' star Ella Purnell discusses how she became a producer for the Sky/Starz serial killer comedy 'Sweetpea' and developing her character.

Exactly how far do you have to push a wallflower before she turns into a Venus flytrap? That’s the question at the center of Starz’s Sweetpea, the dark comedy starring Ella Purnel (Yellowjackets, Fallout) that premiered Thursday.

But Sweetpea protagonist Rhiannon Lewis, played by none other than Yellowjackets alum Ella Purnell, might be a rare exception. Maybe then, she would have had the chance to confront her teenage angst head-on,