During the Shaoxing period of the Southern Song Dynasty, Qin Min, the Minister of Rites, died suddenly on a rainy night. Only the remains of a chess game and the word "Tian Yuan" were left in the secret room. Genius widower Shen Mobai is ordered to investigate the case, and gets acquainted with Qingluan Pavilion secret agent Yan Jiuge, who is disguised as a man, and Cheng Hao, the minister of the Ministry of Justice who hides a deep secret. The three of them peeled off the cocoons and discovered that behind the chess game there was a shocking conspiracy involving Qin Hui's remaining parties and the Kingdom of Jin. When the "Tian Yuan Eighteen Changes" chess game reappeared, a revenge and conspiracy spanning twenty years began, and the cause of Shen Mobai's father's death was the key to solving all the mysteries...
