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.