In 2004, deep in the wilderness of China’s Yunnan province, a group of scientists from the Wuhan Institute of Virology discovered a cave full of wild bats carrying hundreds of SARS-related viruses. Their work, published in a draft paper in 2005, unearthed the link between SARS (severe acute respiratory syndrome) and bats for the first time. Now the virologist who led that study, Shi Zhengli, has revealed one of the strains found in that cave — the exact location of which is a closely guarded secret — is almost identical to the 2019-nCoV coronavirus which has so far killed at least...