The film stars Benedict Cumberbatch as Greville Wynne, and is based on the true story of a British businessman who was recruited by the Secret Intelligence Service to be a message conduit with Russian spy source Oleg Penkovsky (played by Merab Ninidze) in the 1960s.

Wynne establishes seemingly normal business relations with Penkovsky and the latter makes arrangements with western intelligence agencies to feed them information.

Penkovsky learns that the Soviets want to turn Cuba into a nuclear threat to the United States, and relays this information, along with photographs and military plans to the CIA, who eventually verify this using their own intelligence.

Several months later, he is allowed a visit from his wife, who tells him that the Soviets have removed their missiles from Cuba, boosting his morale.

On 1 May 2018, it was announced that FilmNation Entertainment was producing Ironbark, a film about British spy Greville Wynne from a script by Tom O’Connor.

Dominic Cooke was set to direct the film and produce alongside O’Connor, Ben Pugh, Rory Aitken, Adam Ackland, Josh Varney, and Leah Clarke.

[3] In October 2018, it was announced that Rachel Brosnahan, Jessie Buckley, Merab Ninidze, Angus Wright, and Kirill Pirogov had joined the cast of the film.

The website's critics consensus reads: "The Courier delivers a rousingly effective old-school spy adventure elevated by a thrilling fact-based story and Benedict Cumberbatch's nervy central performance.

[19] The Washington Post's Ann Hornaday gave the film 3 out of 4 stars, saying: "The Courier makes a smart, stylish stand for the kind of old-fashioned period spy thriller that is increasingly being turned into bingeable series for streaming services.

"[23] Peter Debruge of Variety called the film "solid if dull-by-definition espionage story" and said: "[The Courier's] hook is that it's based on true events, and the underlying history deserves to be shared.