Tomas Alfredson’s marvellously chill adaptation of John Le Carré’s cold war thriller features a delicate performance from Gary Oldman along with a first-rate supporting cast A thunderstorm rolled into Venice overnight, flash-bulbing the sky and lancing the boil of heat that has enveloped the city these past six days. One could have sworn that the temperature dropped still further, to practically Baltic levels, during the morning screening of Tinker, Tailor, Soldier, Spy, a marvellously chill and acrid cold war thriller from Swedish director Tomas Alfredson. Right here, right now, it’s the film to beat at this year’s festival. Nimbly navigating the labyrinthine source novel by John Le Carré, Alfredson eases us through a run-down 70s London, all the way to a municipal MI6 bunker, out by the train yards. This, it transpires, is “the Circus”, a warren of narrow corridors and smoke-filled offices, patrolled by jumpy, ulcerous men with loose flesh and thinning hair, peering into the shadows in search of a spy. There’s a mole at the top of the Circus, a “deep-penetration agent” leaking secrets to the Soviets. Control (John Hurt) has narrowed the hunt to five likely suspects. Now all that remains is for diffident George Smiley (Gary Oldman), working off the books and under the radar, to steal in and identify the culprit. Oldman gives a deliciously delicate, shaded performance, flitting in and out of the wings like some darting grey lizard. We have the sense that Smiley has seen too much and done too much, and that a lifetime’s experience has bled him of colour. His eyes are tired, his collar too tight, his necktie a noose. Yet still he keeps coming, quietly infiltrating a first-rate supporting cast that includes Mark Strong, Kathy Burke and Colin Firth. Away in Istanbul, Tom Hardy raises the roof as Ricki Tarr, the tale’s bullish rogue element, while Benedict Cumberbatch is mesmerising as the well-groomed gentleman conspirator coming slowly apart at the seams. If Alfredson’s film has a problem, it is only that a quirk in the casting blows the whistle too soon. You don’t need to be George Smiley to grow suspicious of the big-name actor with too much time on his hands. Does this matter? Possibly not, because Tinker, Tailor, Soldier, Spy is finally more about the journey than the destination; more fascinated with the detail than the denouement. The Circus, after all, is precisely that: an outmoded sideshow of clowns, strong-men and acrobats, founded on dodgy principles and banging the drum for a war that may not be a real war anyway. Who cares who is responsible? All these men are guilty of something; all of them drinking from the same dirty water fountain. Tinker, Tailor … treads a shifting, dangerous world where 70s London looks a lot like 70s Moscow and where Santa Claus wears a Lenin mask. It invites us to look from our spy to their spy and treat those two impostors just the same. Rating: 4/5 Venice film festival Venice film festival 2011 Thriller Drama John Le Carré Film adaptations Thrillers Fiction Festivals Xan Brooks guardian.co.uk