The play is adapted from Fenghuangqi's novel "The Song of the Bronze Bird in Chang'an". Shen Du (played by Ding Yuxi), the chief of the inner guard house, is decisive in handling cases but has a "bad reputation". Yan Xing (played by Deng Enxi), a concubine of the Yan family, married Shen Du in place of her sister because her third sister escaped the marriage granted by the Empress Dowager. In order to protect her family, Yan Xing married Shen Du. Strange cases frequently occurred in Beijing. Shen Du and Yan Xing worked together to solve many unsolved cases. Their feelings gradually warmed up in the process of solving the cases. They worked together with their companions to uncover the shocking conspiracy and jointly safeguard peace and justice.