I recently watched the titular film with some friends on the advice of another friend. I didn't know what to expect, I hadn't heard anything about it before then and had no clue what the story was about and therein lies part of the problem I encountered when I watched the film. Overall, I say it was a good movie with a solid story. However, it was only after about the halfway mark I could really start making out what the story was.
This is what the story was as far as I could gather it before I went to wikipedia and looked up the details. Its the cold war, MI-6 is carrying out small operations and one group in particular is involved with particular operations related to battling a counter-intelligence agency of a similar nature in the USSR. During an operation, their agent is betrayed and they come to realize there is a mole in their small group so they bring in a retired agent played by Gary Oldman, aka Commissioner Gordon w/o a mustache and w/ an English accent, to root out this double agent. He meets with another agent who is in hiding b/c he was also betrayed and puts together all this evidence from various witnesses and accounts from people in the agency.
Eventually, somehow the head of the agency, who was shown as dead in the beginning in a flashforward, makes a partial title drop by naming the 4 main members of the agency as tinker, tailor, soldier, and something else I forgot. It wasn't spy though but once you realize that he's the only one with a different name than whats given in the title, you know that character must obviously be the spy and this is about 3/4 of the way through the film. There's also apparently an agent in the USSR counter-intelligence agency who heads it and is the opposite of Gary Oldman's character in this chess game (they use chess pieces to identify the agency members so its a fitting analogy). The UK agency was trying to outsmart him by hiring an obvious double agent as a reverse double agent (so a triple agent) to give false information to the USSR agency. However, they find the mole giving the real information away and compromising MI-6 agents and then in the end they get rid of him tearfully b/c apparently he was a good friend or something before that.
Now I'm glad there's a wikipedia b/c otherwise I'd remain confused about somethings. For one thing, the Russian counterintelligence head was named Carla and one of my friend's accidentally said it was one of the women Gary Oldman talked with and not that guy. More importantly though, the head of the agency, played by John Hurt, aka Evil Dictator from V for Vendetta, did die early in the movie but his image was brought back in flashbacks later. Early in the movie, they show a mission that went bad b/c of the mole and that happened in the past and b/c of it, Gary Oldman and John Hurt and the agent were fired and John Hurt died b/c he was old and sick. Also, the names of the group's members, the group being called "Circus", was not directly in line with the title and the "Spy" was not who the actual Spy was so in saying it was obvious who the spy was, I think I mixed up what I saw and what I read on wiki afterward, no biggy. And of course, there were all these other little things too but I got most of thankfully.
Regardless, this film required some patience in the first part b/c there isn't exactly a proper introduction for every character. I find that it would have been helpful to either have seen a trailer or even read a short introduction about what the movie was gonna be about. This isn't like the "traditional" spy flick either with loads of action and excitement though there is some of that. The excitement and impetus to see the rest of the film comes from wanting to solve this mystery that is undermining a major counter-intelligence organization against a common threat in the west, the USSR, something that is not such a grave threat to the youngins today who didn't live in that era. And when you add a great actor like Gary Oldman in to head the case, you really wanna see him get to the bottom of things and solve this mystery.
I feel like some people who are like that but more accepting of seeing the whole film would not be able to understand it all and would have to see it more than once or read the wiki on it like I did. In that, I admit that I too have kind of short attention span but I am more accepting of different genre's. In fact, I enjoy a lot of old films, black and white included, which most people today groan at having to see while I would trade away a good deal of movies with bazillions of explosions for any one good old film which included and relied on superb acting and story lines more than anything else.
It is true though, b/c this is based off a book, it cannot cover everything that the book probably went into such great deal to explain, especially sometimes when books go into the minds of characters and share their thoughts with us. Maybe I might genuinely have been more disappointed with this movie if I had read the book first but now, I can give it the benefit of the doubt.
BTW, I have NOT proof-read this in anyway, forgive me for any grammar/spelling mistakes.