“It’s a Sin” actor Lydia West is set to star alongside Patricia Clarkson in spy thriller “Gray.”

Stuart Ford’s AGC Studios is financing the eight-part show and will distribute it in the U.S., represented by CAA, while Lionsgate International will handle distribution in the rest of the world.

West co-stars alongside Clarkson, who plays CIA spy Cornelia Gray who emerges from 20 years in hiding, dodging the government agents who suspected her of being a traitor. But just as she returns to her old life, it’s discovered that there’s a new mole in her old spy network.

West replaces “Game of Thrones” star Nathalie Emmanuel, who was previously attached to star in the series.

“Gray” is produced by AGC Television, the television production and distribution arm of AGC Studios. John McLaughlin (“Black Swan”) and international best-selling author David Baldacci (“Absolute Power”) are the writers and creators, while the director is Ruba Nadda (“Queens”), who previously worked with Clarkson on the 2009 romantic drama “Cairo Time.”

Executive producers are AGC’s Ford and AGC Television president Lourdes Diaz, alongside Clarkson, McLaughlin, Baldacci and Nadda. Additional casting is ongoing with the start of production beginning in June on location in Toronto.

West has just been nominated for a BAFTA TV award for lead actress in Russell T. Davies’ “It’s a Sin” for Channel 4. Her other credits include “Years and Years,” “Suspicion” and “Dracula.”