Sixteen years ago, the world was divided into five parts. Gusu Lan, Yunmeng Jiang, Qinghe Nie, Qishan Wen, and Lanling Jin ruled the world together. The Wen family was the only one that dominated, and the other four families suffered. Among the young people, Wei Wuxian, the son of Jiang's old friend, had a cheerful personality. He met Lan Wangji, a disciple of Gusu Lan, who was famous for his elegance and righteousness, and became a confidant. By chance, the two discovered the secret that the Lan family had been guarding for a long time. The two inherited the legacy and eliminated the hidden dangers for the people. But they didn't expect that the mastermind behind all this was Wen Ruohan, the head of the Wen family. The families couldn't bear the humiliation and joined forces to attack the Wen family. After the fall of the Wen family, Wei Wuxian did not hesitate to oppose the families in order to protect the innocent people of the Wen family. In the end, he was harmed by the traitor and caused a disaster. He accidentally harmed his senior sister Jiang Yanli and disappeared. Sixteen years later, Wei Wuxian, who had disappeared for a long time, appeared in Mojiazhuang and met his old friend Lan Wangji. The strange murders in Mojiazhuang seemed confusing. As the truth is revealed step by step, Jin Guangyao, who is behind the scenes, gradually finds it difficult to hide. In the end, Jin Guangyao dies, Lan Wangji takes on the mission of supporting the world, and Wei Wuxian does not forget his original intention and finally lives a carefree life.