The mountain wanderer Zhang Tianzheng became foolish due to poisoning and lived a tranquil life with his grandson Zhang Beichen in Qingshi Village. The appearance of the mysterious woman Duan Siyuan disrupted their originally ordinary life, leading Zhang Beichen to realize how little he knew about his grandfather. Duan Siyuan, whom Zhang Beichen saved, came with the intention of killing him to avenge her parents and mentioned a tragic event from the past in the Secret Door called the 'Change of the Golden Crow.' The two reached an agreement to uncover the truth of the past, and Zhang Beichen decided to inherit his grandfather's Blade of Departure and become a mountain wanderer while unraveling the mystery behind his grandfather's poisoning. Thus, the mountain wanderer Zhang Beichen, the skilled martial artist Duan Siyuan, the ghostly healer Wei Ling'er, and the North Horse Ma Tianhong embarked on a journey to seek the truth. Along the way, they encountered all sorts of strange events. The four youths bravely faced these bizarre occurrences, solving each mystery and witnessing greed, anger, ignorance, and hatred in the world, as well as the most precious human emotions. However, more than that, these seemingly supernatural events were rooted in the vile and petty nature of humanity, as the saying goes, 'There are no ghosts in the world; evil is within the human heart.' A single thought can lead to heaven or hell. The four youths gradually approached the truth, and the mysteries of their parents' generation began to surface, suggesting that a greater conspiracy lay behind the poisoning of their grandfather. The path ahead for the four remains uncertain...