Like much of the rest of Tarkovsky's work, Stalker was a film I was absolutely dreading watching, as it had the potential to be either the most transcendental viewing experience I could ever hope to have or a tedious film that bored me dumb. And there was its formidable reputation as one of the greatest films of all time, a label which is hardly ever encouraging when it's attached to a foreign film. But I put aside my apprehensions and gave Stalker a go.

It's based on the novel Roadside Picnic by Boris and Arkady Strugatsky, a book a couple of members of my family had read but which didn't tickle my fancy as I'm not a fan of sci-fi novels. I can't speak for the book's plot - I've heard it's a loose adaptation - but the film takes place sometime in the future, when a "stalker" makes a living taking people to the Zone, a mysterious prohibited area, so they can have their desires granted in "the Room". His passengers this time are a writer and a professor, and the three of them brave the unknown in search of the Room. The writer's glib attitude masks a heavy insecurity about his art, while the professor insists on keeping the contents of his rucksack a secret.

Tarkovsky uses the film as a means of scrutinising the trio's personalities, motives and attitudes to what they are doing, and evokes the Zone as an unpredictable and densely mysterious place full of low-level trepidation and menace. However, this is no science fiction thrill ride; if 2001 disappointed you in this respect, just wait till you've seen Stalker. Tarkovsky's film is a character study, with the atmosphere of the setting acting as a catalyst for all kinds of ugly truths to be revealed. Most affecting is what we learn about the stalker; he sees himself as a kind of saint devoted to making others happy, but this journey completely deconstructs his belief in his own goodness by confronting him with more obviously conflicted people and exposing a grim side to his beloved Zone.

For a supposed science fiction film, Stalker is one of the most spartan films of its genre, completely devoid of any hi-tech trappings. It plays out amid a drab backdrop of overgrown junkyards and derelict interiors, and we are never taken inside the Room itself. This allows Tarkovsky to focus more on the characters' doubts and dreads about what lies in wait for them, making for a subtler and more meaningful film overall. There are also plenty of the director's signature long takes and controlled camera movement, redirecting the audience's attention onto what the characters do and say - I was surprised how dialogue-driven film this turned out to be. Music is also used sparingly, and the score, when it does come in, enhances the unsettling ambience.

The final ten minutes are possibly the most impactful of any film I've seen for a while, proving the characters' biggest fears right in as quiet a way as possible. Stalker is an ominous and challenging film whose main flaws are its length and pace, but a film that is seemingly so full of meaning that I'm sure I missed a great deal.