A strange female corpse suddenly appeared in Jingshan Wanchunting, which caused the old emperor to relapse. His old illness relapsed and his life was in danger. He urgently wanted to decide on his successor. The eldest prince and the second prince each rushed to recruit troops and win over people's hearts. The old watchman picked up two abandoned children in the Bell and Drum Tower, leaving the boy Xiao Zhong and the girl Xiao Gu to be raised by others. Xiao Zhong joined the Grand Prince's party, made outstanding achievements repeatedly, and was highly regarded. The second prince could not win over him and wanted to get rid of him quickly, so he resorted to countermeasures. Xiao Gu later changed her name to Gu Xian'er and became the first courtesan. The old emperor tested the princes and arranged three contests at the Bell and Drum Tower, Yongding Gate and Zhengyang Gate. The eldest prince and the second prince each won one game. Accompanying the entire struggle for imperial power were numerous unstoppable murders, which also made this political struggle more complicated and confusing. What is the relationship between the old emperor and the female corpse, whether the Jianghu gang conspiracy can succeed, what is the mystery of Xiao Zhong and Xiao Gu's life experience, and who will win the final victory in the imperial court - the answers to all questions will eventually be presented in the decisive battle at Zhengyang Gate!