Strugatsky brothers have a cult following on the territories of the former Soviet Union; think Heinlein of the Soviets. This is probably their best-known novel internationally thanks to a movie Stalker by Tarkovsky and several video games by the same name.
The main idea explained right in the prolog. A highly advanced alien race left (discarded?) artifacts and anomalies in several places on Earth called Zones. The Zones are dangerous, but the artifacts are highly prized and so some people called stalkers smuggle things from Zones. There is a price to pay for these smuggling trips though.
As with a lot of good Soviet science fiction, expect a lot of question asked, no clear answers provided and no happy end. It is a though-provoking, hard-to-put down masterpiece, most probably the best introduction to Soviet science fiction. A must read for any sci-fi fan.