In 1963, during the spring plowing season in rural China, eight-year-old Mu Mian and her friend Xu Lele are abducted by a group of human traffickers while gathering firewood in the mountains. The traffickers, consisting of a tall limping man, a short man, and an elderly woman, transport the children to an abandoned commune building. Unbeknownst to the captors, Mu Mian is not the slow-witted child she appears to be; she is the reincarnation of a twenty-four-year-old woman from the future who transmigrated into the girl's body during the kidnapping. Upon waking in the dilapidated hideout, Mu Mian assesses her dire situation: she is suffering from a high fever, her companion is half-conscious, and they are vastly outnumbered by the adult criminals.
The traffickers are in a rush to relocate because police are tracking them, and they argue over whether to wait for the short man's wife or leave immediately. Realizing that the traffickers plan to drug them again for the journey, Mu Mian decides to act. She feigns illness to obtain fever medicine from the elderly woman, Old Lady Li, to stabilize her condition. When Old Lady Li attempts to drug the children with a soaked handkerchief, Mu Mian violently resists, striking the woman with a wooden stick and killing her. She then confronts the two men as they enter the room. Using her knowledge of combat and the element of surprise, Mu Mian breaks the tall man's leg and head, and incapacitates the short man by kicking him in the groin and striking his head. She escapes with Xu Lele and a third abducted boy, running toward the nearby public security bureau where her cousin, Liu Tao, works. She collapses upon reaching safety, having successfully fought off the kidnappers.
Mu Mian wakes up in the commune hospital, surrounded by her relieved family, including her father Mu Fugui, a slaughterhouse worker, and her grandmother Zhao Meihua. The police confirm that all four traffickers have been apprehended; three were killed by Mu Mian, and the fourth, the short man's wife who had been separated from the group, was arrested. The investigation reveals a larger trafficking network spanning multiple provinces. Mu Mian provides a detailed statement to the officers, demonstrating her sharp intellect and courage, which surprises her family who previously thought her dull.
After recovering, Mu Mian returns to her life in Qingfeng Brigade. She navigates her new identity as a child in a different era, dealing with the economic hardships of the time and the close-knit but poor rural community. Her family, though loving, struggles financially, relying on work points and her father's modest wage. Mu Mian begins to adapt to her surroundings, helping with household chores and interacting with her extended family, including her twin uncles and cousins. She also reflects on her past life as an orphan and finds comfort in her new family bonds. The story establishes her resilience and intelligence as she prepares to face the challenges of living in 1960s China, using her future knowledge to improve her family's circumstances while hiding her true identity.