A mysterious illness had stricken seven patients at a hospital, and a doctor tried to warn his medical school classmates. “Quarantined in the emergency department,” the doctor, Li Wenliang, wrote in an online chat group on Dec. 30, referring to patients. “So frightening,” one recipient replied, before asking about the epidemic that began in China in 2002 and ultimately killed nearly 800 people. “Is SARS coming again?” In the middle of the night, officials from the health authority in the central city of Wuhan summoned Dr. Li, demanding to know why he had shared the information . Three days later, the police compelled him to sign a statement that his warning constituted “illegal behavior.” The illness was not SARS, but something similar: a coronavirus that is now on a relentless march outward from Wuhan, throughout the country and across the […]