This film is so unlike anything I've seen Hollywood churn out recently that I was genuinely staggered. You have to concentrate. Hard. For the entire film. Alfredson gives you no easy routes, and you find yourself crossing your eyes in frustration. Is this a flashback? Is this guy dead? What's happening here? And yet despite how much effort you have to put in, the atmospheric approach makes it seem worth it. A malevolent, dreary London; a secret service turned corrupt bureaucracy. There are no James Bonds here, no glamour. Just paranoia, creeping cynicism, overwhelming nostalgia. Oldman's turn as Smiley is note perfect. Betrayed personally and professionally, doggedly pursuing the truth.

Go in with your thinking hat on. It's worth it.