Iemon Fukasawa, a masterless samurai, marries Oiwa but is repulsed by a dark mark on her face. He descends into alcoholism and starts an affair with O-hana, a maid carrying another man’s child. Together, they conspire to poison Oiwa, killing her and disposing of her body in a moat. But Oiwa’s vengeful spirit rises from the depths, seeking revenge.