During the Empress Wu Zetian's reign, Detective Dee supervised the case of "Red-eyed monster" causing trouble and eliminated Prince Wu Minzhi, who tried to usurp power and seize the throne, preserving the stability of Jiangshan....

Lin Wanqing, the timid and hesitant leader of the Miduoduo Armed Escort Agency, infiltrates the supreme court as a part-time assassin to revive the agency. Su Moyi, the cold and ruthless official of the supreme court, plays along and gets acquainted with the kind Lin Wanqing head-on. They join forces to investigate cases and protect the imperial city, ultimately achieving a successful love story that goes both ways....