The Czechoslovak Socialist Republic hides a secret. In the Brdy Mountains, a phenomenon known as the Zone appeared years ago. It is life-threatening, and its existence is classified. Only the employees of the State Institute for Research and Protection of the Zone, or SUVOP, know about it. Even they cannot enter its territory, where many lives have already been lost. One day, however, after many years, an expedition group sets out to its borders. It consists of the chief commander of SUVOP, Diviak, his predecessor in the same role, Chrobák, researcher Karel Srna, security officer Lev, and technician Vlček. Each of them has a different motive for embarking on a journey from which many before them did not return. The Zone will change everything that occurs within its territory... And the calendar shows the date August 21, 1968.
