In the early years of the Republic of China, the remote northern town of Gulou Town had been troubled for twenty years by a mysterious disease known as 'skeleton disease.' Those afflicted behaved strangely, plagued by hallucinations, and exhibited a repulsion to food while excessively craving water. The patients became emaciated and listless, leading the surrounding populace to humorously nickname Gulou Town as 'Bone Town.' In recent years, Bone Town faced additional troubles; five years ago, a mysterious beast known as the 'black bear' appeared in the nearby hazelnut forest, often intruding into the town and disturbing the locals, adding to the town's woes. In Bone Town, a girl named Sangeng had been learning hunting skills from her master, Sun Laohai, since childhood, honing her exceptional archery skills. However, five years ago, the black bear suddenly emerged, and Sun Laohai was killed while hunting it. Consequently, Sangeng vowed to dedicate her life to hunting the black bear, often wandering the nearby hazelnut forest in search of its traces. One night, a traveling physician named Bai Xiaobai passed by the hazelnut forest outside Bone Town and was suddenly attacked by the black bear. Fortunately, Sangeng appeared just in time to save Bai Xiaobai's life. To her surprise, Sangeng discovered that for some unknown reason, the black bear was terrified of the medicines in Bai Xiaobai's medical kit. However, when she asked Bai Xiaobai, he was also unclear about the reason. To uncover the truth, Sangeng forcefully brought Bai Xiaobai back to the town...