It tells a legendary story that happened in the old forest of Changbai Mountain in the early years of the Republic of China. The protagonist Ma Hengyuan (played by Mou Fengbin) led everyone into the forbidden area of Changbai Mountain, Ganfanpen. In the unique and steep terrain, everyone faced a series of strange things. After experiencing bizarre events such as losing their way, killing each other, and caves swallowing people, they finally worked together to uncover this mysterious picture of the old forest in Northeast China, and realized the power of truth, goodness and beauty from distant legends and personal experiences.