Rated R

Sometimes, the past is a chilling fiction.

John LeCarré’s famous 1974 spy novel, “Tinker, Tailor, Soldier, Spy,” wasn’t written as a period piece, but it seems necessary to treat it that way now. LeCarré himself had worked for British intelligence for years before he quit to become a writer, and though his novels are fiction, they’re steeped in the sort of veracity that could only come from actually living through the Cold War inside the cold heart of MI5 and MI6.

Swedish director Tomas Alfredson (“Let the Right One In”) knows not to mess with that and does not hesitate to take the viewer right back into the early 1970s in this new adaptation. Assiduously filmed on location in London, Budapest and Istanbul, great effort was made to capture the details of that time and to convey the feeling of dread that hung over the grim game of spy chess played between the East and the West for decades. The movie even feels old, as if it might itself have been filmed a few decades ago. Produced in large part by French-based Studio Canal, it hardly feels like an American movie at all, because, thankfully, it’s not.

“Tinker, Tailor, Soldier, Spy” begins with the expulsion of senior British intelligence officer George Smiley (Gary Oldman) from the Secret Intelligence Service (SIS), along with his mentor and friend Control (John Hurt). Shortly thereafter, SIS reaches out to Smiley: there’s suspicion of a Soviet mole high up in British intelligence, and now that Smiley is on the outside, he is uniquely positioned to investigate.

When Control is killed, Smiley is left with a set of cryptic clues as to who Control had suspected of being the mole. Apparently, all of the inner circle was under suspicion, including Smiley himself, as well as Haydon (Colin Firth), Bland (Ciarán Hinds), Esterhase (David Dencik) and Alleline (Toby Jones). His only man on the inside is the young Peter Guillam, played with spectacular hair by Benedict Cumberbatch (of BBC One’s “Sherlock”).

With a cast like that, it’s hard to go wrong. Oldman himself brings a restrained, withdrawn menace to Smiley, who never commits an act of violence in the film yet manages to convey the sense that he certainly could. The toll that the spy game as taken on him hangs on his face like a shroud.

This is not a fast movie, and it’s not easy to follow. In 1979, it was adapted by the BBC into a seven-part series starring Alec Guinness, so this version is surely compressed by comparison. The characters use so much archaic spy jargon that even their casual conversations sometimes could use a decoder ring, but once you’ve got it, it’s rewarding. Who ever said being a spy was easy?

The set for SIS headquarters is a fascinating vision of 1974 hi-tech, looking something like a submarine and an office blended in a transporter accident with hatches, sound-absorbing foam and pulleys.

Knowing how the Cold War played out, it’s harder today than it once was to imagine the Soviets as the big villains. Fortunately, this story is not about bad guys as much as it is about the whole dirty game, and that’s something modern audiences can certainly still relate to.