Seven years ago, Lin Wan was born through a crack in the closing gates of the underworld, carrying two souls: one belonging to the living world and one to the guardian of the underworld's gates. Her very existence is a “key” capable of opening the boundary between yin and yang. To save her life, her grandfather the tomb keeper scattered his soul to become a seal. To give her a chance to live, her father signed a contract with the underworld, trading nine wives for one son. The backlash left him a living corpse. Now, as the century's soul-subduing ritual approaches, the underworld hunts her, a hundred ghosts covet her, and the contract's backlash closes in. Seven-year-old Lin Wan carries her dying father on her back and sets out on a desperate quest to find Kunlun Guixu and restore the balance between yin and yang. Along the way, she faces the equal exchanges of the Yellow Springs Inn, the vengeful bride's ghost at the head of the Bridge of Helplessness, a fight for a return to life in the depths of Wangchuan Valley, and the eerie riddles of a deserted village of paper figures. Every encounter is a gamble with death. The two opposing souls within her could bring about the world's destruction, yet they are also the only power she has.
