In the middle of the Ming Dynasty, although the emperor tried his best to rule the court, the two secret service agencies of Dongchang and Jinyiwei were competing against each other internally, and they were constantly fighting for power. In such a seemingly peaceful but actually crisis-ridden era, Jinyiwei Qianhu Shen Xie, while investigating a strange "Red Rain Suspended Corpse Case", unexpectedly discovered that the clues in the case pointed to his long-lost Miao Jiang Gu girl fiancée - Yun Heng. As the investigation deepens, a shocking conspiracy planned by Qintian Supervisor Pei Wujiu to use the forbidden Miao magic "Twin Gu King" to control the imperial power and subvert the world comes to light.
Shen Xian was forced to join forces with Yun Heng to survive in the crack between "power" and "conscience". Not only did he have to face the risk of his identity being exposed as a scapegoat for Dongchang, but he was also horrified to discover during the investigation that the final host of the male Gu was actually his adoptive father who treated him like a mountain of kindness - the commander of the Jin Yiwei, Lu Yan.
In order to prevent the catastrophe, Yun Heng decided to sacrifice himself by feeding himself with Gu; while Shen Xie, after learning all the truth, put on a disguised mask, pretended to surrender, went deep into the tiger's den, and started a thrilling Infernal Affairs with Pei Wujiu, the mastermind behind the scenes. In the end, in the decisive battle of the Heaven Sacrifice Ceremony, Shen Xie successfully counterattacked and exposed all the evidence of the crime. Yun Heng burned his body with fire and turned into sweet rain, saving the people in the city. After the catastrophe, Shen Xian gave up his ownership position and went to the southwest alone. Finally, he reunited silently with Yun Heng, who miraculously survived, in the land where all the past was buried, and stayed together for the rest of his life.
