“The Courier” explores the saga of Greville Wynne, who’s not only in the possession of the most British name I’ve ever encountered, but he’s partially responsible for preventing the outbreak of nuclear war during the Cuban Missile Crisis of 1962. His story of spying and unlikely partnership with Soviet agent Oleg Penkovsky has been previously explored in two BBC productions over the years, but director Dominic Cooke (“On Chesil Beach”) and screenwriter Tom O’Connor (“The Hitman’s Bodyguard”) try to dig a little deeper into the paranoia and tentative friendship of the arrangement. What initially seems like yet another dry British drama about world history grows substantially darker in its second half, with “The Courier” developing into a serious examination of psychological exhaustion, tracking the mounting pressures of a connection that would eventually stop the possibility of global destruction. Read the rest at Blu-ray.com