During the Republic of China era, there is a widespread rumor about the feng shui theory of burial in Yin house. The saying that getting rich depends on Yang house and a job promotion depends on Yin house, became popular. The position of Mr. Yin-Yang is even more popular because he has the ability to penetrate the dragon's lair and break up the Yin-Yang house. The mysterious custom of rat marriage involves the theory of death in a land where feng shui is extinct. If a Yang person lives in a Yin house, the day when he returns home will bring about evil spirits for seven nights. Two brothers who made a fortune by stealing feng shui have observed filial piety for three years. Behind their true and fake filial piety are hidden taboo stories about carp caves. The Yin person returns to the Yang house and looks for the long-haired woman in red every night. All the clues implicate the three stories, the cause-and-effect is not nonexistent, and the cycle is endless. What is the mystery behind it…