In the south Yunnan region of China, how many unknown secrets are hidden in the middle of the deep mountains and dense forests. Pu Po, an old Yi traditional Chinese medicine practitioner and vice president of the county hospital, and Fang Wen, his unmarried son-in-law, who is a doctor, are walking among the mangrove mountains, searching for the secret recipe for treating bruises and gunshot wounds passed down by the old family of the caretaker of the forest. However, an accident occurs on the way, and Pu Po accidentally falls down the valley, and later a corpse containing Pu Po's ID card is found with a completely disfigured face. This incident makes the old man's daughter, Chunyan, very sad. In a silent night, the daughter sat alone at home, looking at her father's last picture. At that moment, there were footsteps in the yard, and the person who came was Pu Pu, who was supposed to be dead.