Now, as the death toll from the COVID-19 pandemic surges, researchers are scrambling to uncover as much as possible about the biology of the latest coronavirus, named SARS-CoV-2. A profile of the killer is already emerging. Scientists are learning that the virus has evolved an array of adaptations that make it much more lethal than the other coronaviruses humanity has met so far. Unlike close relatives, SARS-CoV-2 can readily attack human cells at multiple points, with the lungs and the throat being the main targets. Once inside the body, the virus makes use of a diverse arsenal of dangerous molecules. And genetic evidence suggests that it has been hiding out in nature possibly for decades.