Cishuang is the goddess of fate in the Netherworld, and Si Yuan is the goddess of fate in the Nine Heavens. In ancient times, the two were twin gods with the same origin. In order to control the order of love in the three realms, Heaven issued the curse of "Two White Heads" - when they meet in person, their hair will turn gray, their lifespan will be shortened for a hundred years, and their responsibilities will be incompatible and they will be separated forever.
For three thousand years, he sank his private line into the River of Forgetfulness every day, while she kept the water of Forgetfulness unfed every night. Looking at each other through the mirror during the Ghost Festival, they were shocked to see each other's fair hair and childlike appearance. The way of heaven is testing, and the evil destiny silk is tied to the wrist; Xuan Qiong punishes me, and my hair grows gray again. She insists on breaking up the relationship (transformed by the same heart knot), and he insists on the marriage book. They are natural enemies, but they insist on forming a fate against nature.
From passing things through the mirror (pickles and sweet cakes) to seeing each other in person (green hair is full of snow), from clearing their memories to being tied to death for life, they swear by their white hair and use broken threads as a network, finally breaking through the shackles of heaven, so that ties and broken ties no longer conflict with each other.
Purpose: Si Yuan is not destined to be destined by God, but she is the only person he wants to hold.