When Liu Yi, a modern medical student doing her internship, opens her eyes after a car accident, she finds herself transported into the body of a scrawny foot soldier in the military camp of the Great An Dynasty, someone so frail that he is about to be kicked out. She also becomes bound to an all-purpose Doctor System. While everyone else joins the army ready to risk their lives, she just wants to survive first. From incising wounds and draining pus to disinfecting and stitching them up, she saves a Commandant with nothing but a scalpel, earning herself a place on the military medical roster after starting out in a makeshift medical tent. But as her surgical skills improve and her rank keeps rising, she goes on to suppress bandits, reform taxation, repair official roads, manage grain supplies, defend cities, and defeat enemies, eventually rising from a humble military medic to a provincial governor. There's just one problem: the entire military camp thinks she's a handsome young soldier, while the refined strategist Cheng Qi has already seen right through her.