In the early 1970s during the Cold War the head of British Intelligence Control resigns after an operation in Budapest Hungary goes badly wrong. It transpires that Control believed one of four senior figures in the service was in fact a Russian agent - a mole - and the Hungary operation was an attempt to identify which of them it was. Smiley had been forced into retirement by the departure of Control but is asked by a senior government figure to investigate a story told to him by a rogue agent Ricky Tarr that there was a mole. Smiley considers that the failure of the Hungary operation and the continuing success of Operation Witchcraft (an apparent source of significant Soviet intelligence) confirms this and takes up the task of finding him.
Review
It really is interesting to read the above reviews. I've just come back from seeing it and thoroughly enjoyed it but I wondered if for people who hadn't read the book or seen the TV series it would make sense and obviously it doesn't. It also doesn't fit the change in perception that the current generation have needing an edit at least every 5 seconds and a linear storyline that's not ageist just what we in a much older generation have left as our inheritance sadly. I really enjoyed the film references whether they are intentional or not they range from Rear Window to La Nuit Americaine to Mr Bean's Holiday to Godard. Gary Oldman as Smiley is very good much colder that AG and as in the book a bit younger. It is also less of the feel of a group of Oxbridge Dons in charge rather ex servicemen as MI5 was in those days. I was in my 20's in the early 1970's and the general dullness of everything during that time comes through very well. I would think that after they edited it they wished they hadn't had some rather crass graffiti so prominent but I remember it was all over London at that time. Good film with a plot that makes you concentrate and you have to use your brain well worth seeing but don't go if you want thrills and spills.