A man known as the bloodthirsty killer roams the forest. The sound of water flowing deep beneath the earth fills his mind. He hears an unknown voice, passing through the depths of his unconscious - his id - emanating from the murmuring of the underground stream. Captivated by this voice, the man descends beneath the woods and is swept away by raging river waters, flowing high in the midst of a storm, and is picked up by a small-town steel mill along the bank of the river. In front of this factory, just next to a pig farm, there is an ancient waterway held together by a large spigot. The waterway resonates with the heat of the water in the man's most primal desires, his id. Before long, terrible incidents begin occurring amongst the frugal people of the mill, until one morning it is discovered that the factory manager has been beaten to death. The criminal is a female employee of the mill, and it is her voice that has summoned the man here. The hatred and sorrow of these two, drawn together in the realm of their id, brings about the appearance of the "Human-hog" monster, which resonates a foul stench. At that moment, the ex-detective who has been pursuing the man arrives at the mill town, as if summoned by fate.