In 1900s San Francisco, a white woman is murdered in Chinatown, and the suspect is a Chinese man. The murder causes a social shock, with public opinion demanding that Chinatown be outlawed. Chinese doctor Qin Fu (LIU Haoran) and Chinese man Ah Gui (WANG Baoqiang) are drawn into the case, and they race against time to find the killer in a battle of wits and courage.