A cutting-edge medical researcher dies in a lab explosion and wakes up in the body of Zhang San, a notorious scoundrel in ancient times, just as Zhang and his gang are about to assault Lin Xiaoxiao. A lightning strike kills the original Zhang, and the doctor takes over, armed with 21st-century medical expertise. He immediately diagnoses Lin’s severe wound as tetanus — known in this era as “golden sore spasm,” an incurable death sentence. Determined to save her, he conceives a plan to produce crude penicillin using ancient methods.
Despite mistrust from Lin and utter bewilderment from his former accomplices Li Si, Wang Er, and Mazi, he treats her wound and directs them to gather equipment. Over several grueling days of experimentation with makeshift tools, his homemade penicillin finally nears completion, defying all expectations.
Just as hope flickers, Lin’s father, a wealthy official, bursts onto the scene. Convinced his daughter has been defiled, he nearly orders Zhang executed. After learning the truth,
