Su Chen, an ordinary courier boy in a second-tier city, mistakenly swallowed a "Mingyu fragment" dug out of the soil of an ancient tomb on a rainy night three years ago. He thought it was a candy soaked soft by the rain, but since then his yin and yang eyes have awakened, he has seen ghosts every night, and his life has completely collapsed. That Ming Jade is not an extraordinary object, but a fragment of the ancient "Yin-Yang Equalizer". Swallowing it is tantamount to signing an "underworld contract" that cannot be broken - from then on, you become a "ghost in the underworld" and must deal with those weird events in the human world for the underworld department that cannot be controlled by the underworld department and cannot be tolerated in the underworld. If the progress bar does not increase, Mingyu's backlash will gradually erode his body and mind until his soul is gone. What's even more strange is that sealed in Mingyu is Liu Tiejun, a member of Qianhu, a member of the Jinyi Guards in the late Ming Dynasty - a "criminal" who has not yet completed his sentence. Old Liu has a bad mouth, loves to brag, and is full of sour official accent, but he has a sharp tongue and protects his shortcomings. He has become Su Chen's only "prison partner." The two restrained and harmed each other, and had to rely on each other: Su Chen completed the task to help Lao Liu commute his sentence, and Lao Liu used his yin energy to help Su Chen fight ghosts. Their souls merged during the battle, and they fought each other until the sky was dark and the earth was dark.