British actor Benedict Cumberbatch is coming off playing a Cold War-era civilian spy in the thriller “The Courier” and is getting another shot at the genre for a new HBO limited series, “Londongrad,” based on the book “The Terminal Spy” by Alan Cowell. According to Variety, Cumberbatch will play real-life former KGB Agent Alexander Litvinenko, who famously was poisoned while in England with the radioactive isotope polonium-2010 back in 2006 after defecting from Russia.