In the Dali Dynasty, it seems that spring is as deep as the sea, but in fact, there are undercurrents; the unexplained disappearance of Xiliang leader Mu An has pushed the power dispute to the extreme. Mu An's daughter Mu Qing embarks on the road to find her father alone, wandering in troubled times, the second master from Chang'an City, and Mr. Su in the lost valley. Can Mu Qing see the truth of the world, and whose hand will she take care of these long years?