EXCLUSIVE: Downton Abbey alum Allen Leech has been cast as one of the leads opposite Sophia Bush in CBS’ drama pilot Surveillance, from Matt Reeves, David C. White, Patricia Riggen and 20th Century Fox TV, which will co-produce with CBS TV Studios.

Written by White, with Riggen set to direct, Surveillance is described as a complex and timely spy thriller centered on the head of communications for the NSA, Maddy (Bush), a charming operative who finds her loyalties torn between protecting the government’s secrets and her own.

Leech will play Mike, Maddy’s (Bush) husband and an accomplished former CIA operative. In addition to Bush, he joins recently cast Catalina Sandino Moreno, Matthew Modine and Raphael Acloque.

Reeves executive produces via his 6th & Idaho production company alongside Riggen; White co-executive produces.

Leech currently co-stars in the Queen biopic, Bohemian Rhapsody, which has grossed $285 million worldwide to date.  Leech also is reprising his role of fan favorite Tom Branson, the chauffeur-turned-estate manager, in the Downton Abbey followup movie to the hugely popular TV series of the same name.

Leech, who recently co-starred on the series Bellevue and also co-starred in The Imitation Game, is repped by UTA, Untitled and Troika.