Living a premature and somewhat humbling retirement, elderly British spy George Smiley (Alec Guinness) is abruptly resurrected by his former boss Lacon (Anthony Bate) with an ultra-secret mission: find the double agent in the ranks of the British Secret Service. Is it the pompous head of service, Percy Alleline (Michael Aldridge)? The blowsy Bland (Terence Rigby)? The shifty Toby Esterhase (Bernard Hepdon)? Or perhaps the urbane Bill Haydon (Ian Richardson)? Pushed into retirement by a scandal caused by the now-deceased head of service, Control (Alexander Knox), and because he suspected that there was a spy, Smiley journeys through the labyrinthine world of the British spy service layer by layer as he hunts the mole controlled by the mysterious Russian spymaster Karla (Patrick Stewart). Taken from a best-selling novel by internationally famed novelist John Le Carré, this nearly five-hour miniseries was first broadcast by the BBC. The story is loosely based on the infamous Kim Philby spy scandal of the early '60s.