Andrei Tarkovsky’s masterpiece, which, like his earlier Solaris, is a very free and allegorical adaptation of an SF novel (Arkady and Boris Strugatsky’s Roadside Picnic). After a strange meteorite hits the earth, the region where it fell is sealed off; known as the Zone, it is believed to have magical powers that can grant the most secret wishes of those who enter it, but it can be penetrated only illegally and with special guides. One such guide (Alexander Kaidanovsky), the stalker of the title, leads a writer and a professor (Nikolai Grinko and Anatoli Solonitsin) through the grimiest litter of industrial waste that you’ve ever seen to reach the Zone’s epiphany. What they find is pretty harsh and it has none of the usual satisfactions of SF quests. But Tarkovsky, who regards their journey as a contemporary spiritual quest, does such remarkable things with his mise en scene–particularly very slow and elaborately choreographed camera movements–that you may be mesmerized nonetheless. The film’s final scene is absolutely breathtaking. Not an easy film (and it runs 161 minutes), but almost certainly a great one. With Alice Friendlich (1979). (Facets Multimedia Center, 1517 W. Fullerton, Monday through Thursday, August 27 through 30, 7:30, 281-4114)