Stage alum Harriet Walter has joined the third season of Phoebe Waller-Bridge’s Killing Eve. The Tony nominee and Olivier Award winner joins Danny Sapani, best known for his roles in Penny Dreadful and The Crown as new additions to the crime thriller.

It is unclear who the two performers will be portraying, but Deadline reports that production is already underway for the third season. Continuing the trend of having a female head writer each season is Suzanne Heathcote, who will also serve as executive producer. Season 1 was led by Waller-Bridge (Fleabag), with Season 2 written by Emerald Fennell.

Killing Eve stars Sandra Oh as detective Eve and Jodie Comer as assassin Villanelle, who develop a strange bond that leads a dangerous game of cat-and-mouse and obsession with one another. The series, based on the Codename Villanelle novellas by Luke Jennings, earned a total of nine Emmy nominations for its second season, including Outstanding Actress in a Drama Series for both leads.

Walter’s recent TV credits include Succession and The Crown. She earned a Tony nomination for her role as Elizabeth of England in Mary Stuart and won an Olivier Award for her triple-decker year in 1988, playing Dasha in A Question of Geography, Viola in Twelfth Night, and Masha in Three Sisters.