The mystery of the death of a group of Sverdlovsk tourists in the late 50s still excites researchers around the world, continuing to remain mysterious and incomprehensible. There are dozens of versions about what happened in the Northern Urals on February 1, 1959, but not a single theory fully and consistently reveals the tragedy of the death of nine students of the Dyatlov group. Journalist and writer Sasha Vilensky presents his view of this story, systematizes already known facts and focuses on the logic of the development of events and the psychology of the participants in these events.