"Lapsi" is a Russian mystical thriller about a team of virologists who find themselves on an island where the locals worship a strange deity. Two doctors, Nikolai and Vera, are sent to the north to find the source of an epidemic that has engulfed the region. They themselves become victims of the virus but, thanks to some unknown force, they are completely cured. The couple learns that they will have to spend the rest of their lives in a community that worships the enigmatic Lapsi. They never lose hope of escaping, especially when a helicopter arrives on the island with supplies.