In the old paper shop at the east end of the town, the 16-year-old Amu took the "A Brief Note on Yin and Yang" handed over by his grandmother before she died, and then realized that the yellow paper charms and peach wood swords that were strictly forbidden to be touched were actually the yin and yang world that his grandmother had blocked for him for eighteen years.
After grandma left, the sound of knocking on the door in the rainy night, the lingering dark shadow in front of the grave, and the resentful spirits haunting the living all came to the door one by one. Relying on an old diary and paper-making skills, Amu began to learn to deal with bizarre things: guiding the souls of the first seven reincarnations, rescuing villagers who were haunted by evil spirits, confronting Li Sha in a mass grave, and suppressing old grievances at an old well.
The joints of paper figures need to be glued with cinnabar and glutinous rice water, the paper boats need to be coated with tung oil to prevent yin water, and the yellow paper talismans need to be painted with the blood of a rooster to be effective. The rules of yin and yang are hidden in the skills taught by grandma. The past events recorded in the letters, the well-kept rumors among the neighbors, and the secrets buried in the tombs are pieced together little by little about grandma's unknown past, and Amu is also involved in a life-and-death entanglement.
Guarding the small paper shop, Amu walked on the edge of the intersection of yin and yang, using his mortal body to protect the peace of one party. But he gradually discovered that behind the "evil pieces" that haunt people, there are often hidden human hearts that are more complex than ghosts, and the road he has to go is far longer than making paper figures and drawing spells.
