Just as the mood of Swedish director Tomas Alfredson’s last film, Let the Right One In, was dominated by an icy stillness, in Tinker Tailor Soldier Spy, the director creates the feeling that his characters are moving in slow motion, that the mechanics of the film are stuck in molasses. Tinker Tailor Soldier Spy is a pensive, heavy moving thing, a thriller that never ratchets-up and is instead content to allow the excitement to exist in the pure unfolding of its multi-layered intrigue. It is deeply psychologically intelligent, always staying in front of its audience and unafraid to mask its own characters, challenging the audience to take up the chance of deciphering their many nuances. To this end, Tinker Tailor Soldier Spy rides on a handful of performances that are monumental achievements of minimalist acting.

At the center, is Gary Oldman’s Smiley, a poker-face wearing senior member of the “circus,” the term the spies use for their inner ring. At the film’s start, Smiley is forced out of the intelligence service by his boss, Control (John Hurt), after a mission in Hungary goes bust and one of their men is captured by the KGB. Smiley takes the dismissal without uttering a word, and as Alfredson brings us through the title-sequence montage that sets up the film’s internal dynamics, we see the stoic returning to normal life, a fish out of water shown swimming in a local swimming hole. At first it is difficult to read Oldman’s character, and we have to get to know Smiley. Once we do we notice it is sometimes the slightest twitch of an eyebrow that tells us volumes about what his character is thinking. It is his singular performance that lends this movie its unrelenting sense of tension.

Smiley isn’t out of the game for long. He is soon approached by government men who believe there is a mole operating at the highest levels of the British intelligence service. Smiley is hired to sniff him out, and in the process learns that Control knew all along of the internal threat. Everyone is suspect, and Tinker Tailor Soldier Spy moves us through successive suspicions, introducing us to the maybe traitors who hold their meeting in the sound-proofed inner sanctum of the circus: Percy Alleline (Toby Jomes), Toby Esterhase (David Dencik), Roy Bland (Ciaran Hinds), and Bill Haydon (Colin Firth). And all these actors are simply brilliant.

The great achievement of Tinker Tailor Soldier Spy is its ability to create an environment that seems so plain and yet manages to continually disorient. Chess is used as an obvious metaphor in the film, and each character jockeys for control of space on the board. But it is equally a game of charades. Nothing is as it seems, and the subtleties of the entangled relationships and motives continue to unfold in your mind long after the film ends.