Someone is asking for forgiveness.

On the deserted shore of Lake Baikal, a fisherman is found dead from a heart attack. The situation seems obvious - death from natural causes, but Felix Verbin has doubts and decides to investigate a case that doesn't exist, to learn about an old expedition to the mysterious Cape Rytii, all of whose participants are considered dead, and how it is connected to terrifying events in modern Irkutsk. Baikal is an ancient, sacred sea... Legends intertwine with reality on its shores and become part of everyday life, filling life with the unexplained. Some try to explore the mysteries of Baikal from a scientific point of view, while others believe in their mystical essence. Some try to stay away from the unusual, while for others, turning to the Mystery becomes their last chance for salvation. But everything in the world has a price, and sometimes it turns out to be exorbitantly high.