Strange Door and Dark Blade

During the peaceful period of Song and Liao, Tang Ziyan, an agent originally trained by the secret organization "Phoenix Fire Army," is placed in the Imperial City Department in Beijing. While Tang Ziyan wanted to quietly quit and have a peaceful remainder of her life with her husband Zhou Qian, her husband was taken away by the Phoenix Fire Army to threaten Tang Ziyan. She now has a new mission set by the army: To assassinate the visiting envoy of the Northern Dynasty.