In this uniquely insightful book, a scientist and a writer join forces to try to get to the bottom of how a virus whose closest relations live in bats in subtropical southern China somehow managed to begin spreading among people more than 1,500 kilometres away in the city of Wuhan. They grapple with the baffling fact that the virus left none of the expected traces that such outbreaks usually create: no infected market animals or wildlife, no chains of early cases in travellers to the city, no smouldering epidemic in a rural area, no rapid adaptation of the virus to its new host—human beings. To try to solve this pressing mystery, Viral delves deep into the events of 2019 leading up to 2021, the details of what went on in animal markets and virology laboratories, the records and data hidden from sight within archived Chinese theses and websites, and the clues that can be coaxed from the very text of the virus’s own genetic code. The result is a gripping detective story that takes the reader deeper and deeper into a metaphorical cave of mystery.