Five hundred years ago, Grandmaster Tianxuan sealed the King of All Demons, in exchange for a prosperous and peaceful world. However, the good times were short-lived. Demons lurked in the peaceful town of Qui Yuan, and cholera resurfaced. In order to protect justice and peace, the young demon hunters are eager to try their luck. A young man named Qian Youdao, who dreams of becoming the best demon hunter in the world, stands out from the crowd. But as a strange case comes to an end, they discover a shocking secret....