The Cuban Missile Crisis is often remembered as a time when the Soviet Union and the United States came to the brink of nuclear war. While the puffing of political chests between Soviet First Secretary Nikita Khruschev and U.S. President John F. Kenney played out on the airwaves, it was men like British businessman Greville Wynne who were the unlikely heroes behind the scenes. Dominic Cooke’s Cold War thriller The Courier charts how a man like Wynne found himself intwined in international espionage.

Based on true events, Cooke’s film documents how Wynne (Benedict Cumberbatch) was recruited by a CIA operative, Emily Donovan (Rachel Brosnahan), and a MI6 operative, Dickie Franks (Angus Wright) to help obtain information about the Soviet nuclear program. The assignment was simple, Wynne would essentially play himself, a businessman who wines and dines potential clients in hopes of securing lucrative contracts. While his cover was that he was looking to expand business into the Soviet Union, Wynne’s real objective was to work as a courier sneaking out information acquired by Soviet official Oleg Penkovsky (Merab Ninidze), operating under the codename Ironbark, and passing them onto MI6.

Though Wynne was inexperienced in the world of espionage, Penkovsky found him to be the perfect courier as he did not initially grasp the full ramifications of the intel he was transporting. Hiding the dangers of their jobs from their families, leading Wynne’s wife to suspect he was having an affair, neither man could have anticipated the genuine bonds of friendship that they would form. A bond that would find Wynne risking his life for the slim chance of helping Penkovsky and his family defect out of the Soviet Union.

Although Cooke presents the defection attempt with the tense energy of a heist film, much of The Courier plays like a classic spy tale. It is a film where characters hide in plain sight and constantly look over their shoulders fearing their cover could be blown at any moment. While Cooke’s film is a slow burn, the viewer is always aware of the personal and global stakes at play. A large part of this is due to the fine performances by ensemble cast.

Cumberbatch is convincing as Wynne, bringing the right mixture of aggression, paranoia, and vulnerability to the role. One feels the sense of anguish and defiance that is festering within Wynne as he endures two years in a brutal Soviet prison after being arrested for being a spy. While Cumberbatch brings us into the world of espionage, it is Ninidze’s riveting turn as Penkovsky who proves to be the heart of the film. Ninidze takes what would have otherwise been a conventional film and injects it with earnest emotion. This allows the camaraderie between the Wynne and Penkovsky to feel authentic, reminding us that despite coming from different worlds they were more alike than they think.

The Courier may not stray from traditional tropes of the genre, but there is plenty here to maintain one’s interest. It is a film that shows that two people can change the world, even if they had to do most of it in secret.

The Courier arrives on digital and on-demand on April 16th.