Highly highly recommend the old BBC series (Granada television?) of "Tinker, Tailor, Soldier, Spy" and "Smiley's People", starring the inimitable Sir Alec Guinn

Highly highly recommend the old BBC series (Granada television?) of "Tinker, Tailor, Soldier, Spy" and "Smiley's People", starring the inimitable Sir Alec Guinness as George Smiley. Some of it is on YouTube. To get a taste of the high quality, search for "The Turning of Grigoriev" on YouTube.