Potap is distributed to a small northern town. He goes fishing with a new friend into the forest. However, there they are attacked by a murderous maniac. Out of fear and horror, Potap runs into the forest, to the water. He falls, drowns in the river, comes to his senses in a cave. There he discovers a huge city under the mountain where people live. Disappeared. Of their own free will, not wanting to go back.