Seven years ago, Lin Wan was born in the closed gap of the ghost gate, with the twin souls of "a person from the Yang world" and a "gatekeeper of the underworld". Her existence itself is a "key" that can open the two realms of yin and yang. In order to save her life, the soul of the gravekeeper's grandfather was turned into a seal; in exchange for her life, her father signed a contract with the underworld of nine wives in exchange for one son, but was turned into a living dead. When the hundred-year soul-suppressing ceremony comes, the underworld hunts, the ghosts covet, and the backlash of the contract follow one after another. Seven-year-old Lin Wan, carrying her dying father on her back, embarks on a desperate journey to find Kunlun and return to ruins, and to reset the yin and yang. Along the way, there are equal exchanges at the Huangquan Inn, the resentment of the wedding dress at the Naihe Bridge, the struggle to return to the sun at the bottom of the Forgotten River Valley, the strange mystery of the deserted paper man village... Every time is a gamble of life and death. The two opposing souls in her body are the disaster that destroys the world, and they are also her only strength.
