In Kirigakure City, a coastal city shrouded in fog all year round, serial murders occurred one after another. Next to each victim was a strange bronze butterfly. Young detective Shen Xingyao is involved in this intricate mystery in order to track down the murderer of his sister. During the investigation, he discovered that behind the case there were centuries-old family secrets, the conspiracy of a mysterious organization, and a shocking plan that could subvert the city. While fighting side by side with the cold forensic doctor Su Wanqing, the mysterious rich man Lu Chenzhou, the police elite Gu Chengchuan and others, Shen Xingyao gradually uncovered layers of fog, but also fell into an ultimate game of life, death and justice.
