In San Francisco in the 1900s, a white woman is murdered in Chinatown, and the suspect is Chinese. The murder causes social shock and public calls for Chinatown to be outlawed. Chinese medic QIN FU (LIU Haoran) and Chinese Ah Gui (WANG Baoqiang) are involved in the case and race against time to find the killer amidst a battle of wits and courage.