【Introduction】
The background of the story is set in the peaceful period of Song and Liao Dynasties. A secret organization "Fenghuo Army" operates secretly and trains agent Tang Ziyan (played by Liu Yongxi). She was assigned to serve in the Imperial City Department of Kyoto, and originally wanted to retire and enjoy a peaceful life as a couple with her husband Zhou Qianan. However, Zhou Qianan was captured by the Fenghuo Army and became their bargaining chip to coerce Tang Ziyan. In order to save her husband, Tang Ziyan was forced to accept a new task: to assassinate the visiting Northern Dynasty envoy Huang Taidi. During the mission, Zhou Qian'an was unfortunately shot and killed by Feng Huo Army. This incident deeply touched Tang Ziyan, who was determined to bring down Feng Huo Army and avenge her husband.
Tang Ziyan decided to pretend to be unmoved and continue to go deep into the Fenghuo Army to prepare the next assassination plan. However, she unexpectedly discovered that the contact person was beside her, which made the situation more complicated. In the end, with the help of the emperor's brother, Tang Ziyan successfully cooperated with him and set up a game to narrowly defeat the Feng Huo Army. The chaos was put down and peace returned to Kyoto.