Hugh Bonneville, best known for playing Earl of Grantham Robert Crawley in "Downton Abbey", will guest star in the upcoming espionage political thriller series "The Agency".

Award-winning filmmaker Joe Wright will direct the first two episodes of the 10-part series, penned by Jez and John-Henry Butterworth, reported Variety.

Bonneville will essay the role of James Richardson, described as "a British agent who has a long-standing history with Martian".

The actor joins previously announced cast members Michael Fassbender, Jeffrey Wright, Jodie Turner-Smith, Katherine Waterston, John Magaro, Alex Reznik, Andrew Brooke, Harriet Sansom Harris, India Fowler, Saura Lightfoot-Leon, Reza Brojerdi, and Richard Gere.

Based on the French show "Le Bureau des Legendes", "The Agency" will follow Martian (Fassbender), a covert CIA agent, ordered to abandon his undercover life and return to London Station.

"When the love he left behind reappears, romance reignites. His career, his real identity and his mission are pitted against his heart; hurling them both into a deadly game of international intrigue and espionage," read the official logline.

"The Agency" is set up at streaming platform Paramount+ with Showtime.

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