Roadside Picnic by Arkady Strugatsky and Boris Strugatsky

July's book is a philosophical Soviet-era science fiction novel that was the inspiration for the classic film "Stalker" by Andrei Tarkovsky.

In a world that is coping with a extraterrestrial event, six "zones" exist that exhibit strange and dangerous phenomena and contain artifacts with inexplicable properties. While the zones are tightly controlled by governments, there are stalkers who enter the zones and steal the artifacts for profit. "Roadside Picnic" follows the life of one of them for the next 8 years.

"Roadside Picnic" was first published in 1972, and published in English in 1977. The English version went out of print, but was re-released in 2012. This version is a new translation, and is also based on a revised Russian version that the authors restored to its original state, before the Soviet censors had made their alterations.

Goodreads summary
Red Schuhart is a stalker, one of those young rebels who are compelled, in spite of extreme danger, to venture illegally into the Zone to collect the mysterious artifacts that the alien visitors left scattered around. His life is dominated by the place and the thriving black market in the alien products. But when he and his friend Kirill go into the Zone together to pick up a “full empty,” something goes wrong. And the news he gets from his girlfriend upon his return makes it inevitable that he’ll keep going back to the Zone, again and again, until he finds the answer to all his problems.