In the three years because the covid-19 pandemic began, one of the persistent questions has been how the virus that induced it—SARS-CoV2—first jumped from animals to people. SARS-CoV2 is certainly one of a gaggle of viruses, often known as coronaviruses, generally found in bats. But bats are not often found in Wuhan, the Chinese metropolis during which the virus emerged in December 2019. So how did people near to be infected? Two theories have emerged: the “zoonotic” speculation, whose proponents argue that the virus jumped from animals to people at a market in Wuhan; and the “lab leak” principle, based on which the virus escaped from a laboratory in the city. Which is true?