Tikhvin marshes

On the Vepskaya upland, in the forests north of St. Petersburg (more precisely, the northwest of the Leningrad region), dozens of people disappear, it is not always possible to find corpses.

The hypothesis expressed by the research group of scientists "Labyrinth": people are attacked by flying snakes, which, it turns out, are many in the swamps of the Leningrad region, and which affect people so much that they lose their minds and die.