The emissaries of the underworld are black and white - the elegant and calm Xie Bi'an and the cold and iron-faced Fan Wujiu are ordered to investigate bizarre murder cases in the underworld: the souls of living people have not returned to the underworld, ghosts have been brutally murdered, and strange silver powder and demonic energy remain at the scene. The clue pointed to the ancient fallen angel "Night Wanderer", and as the investigation deepened, the two discovered that the case was actually related to a "Shuang Impermanence Rebellion" that was deliberately buried by the underworld three hundred years ago. When the fragments of memory were gradually pieced together, they were shocked to realize that the bond between each other in their past lives was far deeper than they imagined - Xie Bian was the reincarnation of Bai Wuchang after his soul was shattered, and Fan Wujiu was the clone of Hei Wuchang whose memory had been washed away. The mastermind behind the scenes was the Night Traveler who led them to tragedy! On the day when yin and yang meet, the gate of the underworld will collapse, and thousands of evil ghosts are ready to attack. Can the black and white impermanence let go of their hearts and use the power of soul unity to recreate the ultimate blow of the "yin and yang judgment"?
