In the early Republic of China, the remote northern town of Gulu Town had been troubled for twenty years by a mysterious illness known as 'Skeleton Disease.' Those afflicted exhibited strange behaviors and were tormented by hallucinations, leading to anorexia and a craving for water; the patients became emaciated and lethargic. As a result, Gulu Town earned the mocking nickname 'Bone Town' from the surrounding populace. In recent years, Bone Town faced additional troubles; five years ago, a mysterious wild beast known as 'Black Bear' appeared in the nearby hazelnut forest, frequently intruding into the town and causing distress among the citizens, further exacerbating their plight. In Bone Town, a girl named Sanger had been learning hunting skills from her master, Old Sun Hai, since childhood, honing her exceptional archery skills. Unexpectedly, five years ago, when the Black Bear suddenly appeared, Sun Hai was killed while trying to hunt it. This led Sanger to vow that she would dedicate her life to hunting the Black Bear, often searching the nearby hazelnut forest for its traces. One night, a wandering young doctor named Bai Xiaobai was passing through the hazelnut forest outside Bone Town when he was suddenly attacked by the Black Bear. Fortunately, Sanger showed up just in time to save Bai Xiaobai's life. Sanger was intrigued to discover that the Black Bear seemed to fear the medicines in Bai Xiaobai's medical kit, but after inquiring, Bai Xiaobai did not know the reason either. To uncover the truth, Sanger stubbornly took Bai Xiaobai back to Bone Town in an attempt to solve the mystery. Upon arriving in the town, Bai Xiaobai discovered that many townspeople were suffering from the Skeleton Disease. With the doctor's keen senses, he realized that everything was not as simple as it seemed on the surface, but at the same time, danger was quietly approaching him...
