During the Taiping period of the Song, Liao, and Qing dynasties, Tang Ziyan, a secret agent trained by the secret organization Fenghuo Army, was placed in the Imperial City Department of Kyoto. When she wanted to retire and spend her life with her husband Zhou Qian'an, her husband was captured by the Fenghuo ArmyUnder coercion, Tang Ziyan was tasked with a new task: to assassinate the visiting envoy of the Northern Court, Emperor Taidi. During this period, before Zhou Qian'an was shot and killed by the Fenghuo army, Tang Ziyan was determined to overthrow the Fenghuo army, pretending not to be moved and continuing to penetrate deeperThe next assassination plan, only to realize that the contact person was right beside them. In the end, Tang, along with his younger brother, worked together to narrowly defeat the Phoenix Fire Army, quelling a rebellion and restoring peace to Kyoto.