Stalker (Russian: Сталкер; IPA: [ˈstɑlkʲɪr]) is a 1979 Soviet science fiction art film directed by Andrei Tarkovsky, with its screenplay written by Boris and Arkady Strugatsky. Loosely based on their novel Roadside Picnic (1972), the film features a mixture of elements from the science fiction genre with dramatic philosophical and psychological themes.
It depicts an expedition led by a figure known as the "Stalker" (Aleksandr Kaidanovsky) to take his two clients, a melancholic writer (Anatoli Solonitsyn) seeking inspiration and a professor (Nikolai Grinko) seeking scientific discovery, to a mysterious restricted site known simply as the "Zone", where there is a room with the supposed ability to fulfill a person's innermost desires. The trio travels through unnerving areas filled with the debris of modern society while engaging in many arguments, facing the fact that the "Zone" itself appears sentient, while their path through it can be sensed but not seen. In the film, a stalker is a professional guide to the Zone, someone having the ability and desire to cross the border into the dangerous and forbidden place with a specific goal.
The meaning of the word "stalk" was derived from its use by the aforementioned Strugatsky brothers in their novel Roadside Picnic, making an allusion to Rudyard Kipling's character "Stalky" from the Stalky & Co. stories. In Roadside Picnic, "Stalker" was a common nickname for men engaged in the illegal trade of prospecting for and smuggling alien artifacts from the mysterious and dangerous "Zone". The English language definition of the term "stalking" was also cited by Andrei Tarkovsky.
The film has received many positive reviews, being labeled as one of the best drama films of the latter half of the 20th century, and ranks #29 on the British Film Institute's "50 Greatest Films of All Time" poll.
[source: wikipedia entry on Stalker]