The Prince of Wei Nan, Duan Yan, steals the Painting of Splendid Landscape from the Duke of Jing An so he can sell it to the enemy. Hidden in the painting are the landscape and military defenses of Dasheng. Shan Shui Du Master, Wen Si Yuan, sends a frail but sharp doctor, Zuo Qing Ci, along with a thief, and two disciples from Zheng Yang Palace, Shen Man Qing and Yin Chang Ge, to retrieve the painting. (Source: frankly at MyDramaList)