Yun Shuang, a modern police officer known as the Iron-Blooded Police Flower, is shot in the line of duty and awakens in the body of a woman with the same name in the ancient Kingdom of Da Qi. The original host was a low-ranking magistrate's daughter who eloped with a deceitful scholar, was betrayed and assaulted, and subsequently gave birth to twins in poverty. After years of despair and illness, she died, leaving her five-year-old children, Yun Erya and Goudan, malnourished and struggling to survive in a dilapidated shack in Xiazhou, a military household settlement near the border.
Yun Shuang quickly assesses her dire situation: the family possesses only ten copper coins and no food. She rejects the passive despair of her predecessor, using her modern knowledge and police training to stabilize her household. She cooks a nutritious meal from foraged mushrooms and fish, earning her children's tentative trust. Her son, Goudan, is fiercely protective but traumatized by years of neglect, while her daughter, Erya, is sweet but naive. Yun Shuang begins to teach the children survival skills and moral principles, aiming to raise them with dignity despite their poverty.
The local social dynamics are hostile. Sister Miao, the village chief's wife, repeatedly attempts to pressure Yun Shuang into marrying her intellectually disabled son, intending to use Goudan as a future laborer and military substitute. Yun Shuang firmly rejects these advances, exposing the mutual utility of her presence in the village to the village chief. Meanwhile, Liu Pei'er, the village's most beautiful girl and Yun Shuang's rival, harbors jealousy and spreads rumors about Yun Shuang's past. Yun Shuang handles these threats with cold logic and sharp wit, refusing to be bullied.
A significant turning point occurs when garrison soldiers arrive to arrest a deserter, Wu Chengqi, who had previously harassed the original Yun Shuang. Yun Shuang observes the search at the Wu household and notices inconsistencies: yellow mud on the parents' shoes and greasy dishes indicating recent heavy cooking. She approaches the commanding officers, Deputy Commander Yan Fang and Captain Chen Ye, and provides precise intelligence about the deserter's hiding place at Doghead Mountain. The soldiers capture Wu Chengqi, and Yun Shuang is rewarded with two strings of cash by General Jiang Xiao, the ruthless commander of the Xiazhou garrison.
The encounter with General Jiang Xiao leaves a lasting impression on him due to Yun Shuang's unusual composure and directness. He had been searching for a woman from six years prior who saved his life, and her resemblance to his memories intrigues him. Yun Shuang uses the reward money to buy ingredients and plans to start a small business, discovering a grove of hawthorn trees that she intends to process into candied snacks, a delicacy not yet popular in the border region. However, her plans are interrupted when Erya falls severely ill with a high fever, forcing Yun Shuang to confront the immediate dangers of healthcare in an ancient setting while navigating the growing attention of the powerful general.
