Su Wanqing, a female journalist in Republican-era Shanghai, returns to Yunqi Town to investigate a case, only to discover that the townspeople wear eerie smiles and have collectively lost their memories. She also learns that she visited the town three years ago, but those memories were sealed away. With the help of Gu Yanzhi, an inheritor of the traditional bone-setting art, she uncovers the secrets behind the Guiyuan Technique and the Worry-Erasing Soup. The Pure World Society has long been under Japanese control, plotting to strip ordinary people of their memories and destroy the nation's will. Together, they storm the society's headquarters on Mount Longhu and seize the incriminating evidence. True Guiyuan has never meant forgetting pain, but recovering one's memories and holding fast to one's true self.