Trimonium group is a powerful corporation engaged in mining the rare metal - Trimonium in the territory of the Caucasian Mineral Waters. Thanks to the miraculous properties of the mineral, many lives have been saved. But is it really so? Mirgorod, shrouded in the ashes of Elbrus, is surrounded by a high wall. Anyone who approaches it is doomed to death. Retired police captain Viktor Korotkov challenges the corporations leader. His goal is to bring down the wall and reveal the truth to the world. Korotkov does not yet know that the world he remembers no longer exists.