She rises from the bottom of the lake, and her appearance is terrible. Anyone can be dragged away by the Underwater Horror into the impenetrable darkness of the lake depths. Meeting her does not bode well for people. And why did Kolka and the boys start playing games on a deserted island in the middle of the lake?.. Now the boy has to perform some strange tasks of dark power: he digs up a skull from an old grave, brings a cross from a cemetery to the island... And he cannot refuse this work - if Kolka will not perform the terrible rituals, his fate will be terrible...