Set in the 1960s when the prospect of nuclear war was very real, and based on a true story, The Courier recounts how Greville Wynne, a seemingly ordinary British businessman is recruited by the CIA and MI6. They enlist him to use his ability to legitimately travel to the Soviet Union to gain details of the movement of missiles to Cuba.

Originally this was called Ironbark, the code name of Wynne’s Soviet source, Oleg Penkovsky which is a much better title than the derivative and often used The Courier. Benedict Cumberbatch stars as Wynne and this is his juiciest part since The Imitation Game. He brings just the right amount of charm and naivety to the role.

Merab Ninidze is impressive as Oleg but it is the supporting cast of Rachel Brosnahan, Anton Lesser and Angus Wright as the professional spies that I enjoyed watching the most. It is a shame that the brilliant Jessie Buckley has a thankless thin part of Greville’s wife.

Director Dominic Cooke keeps things bubbling along in the first half as heroic amounts of alcohol and cigarettes are consumed. The highlight of the film comes later as the Soviet authorities close in on Oleg and Greville to nail-biting effect.

The remainder of the movie does not quite live up to that, but this is an engrossing look at a scary time in history.

Rating: 8 out of 10