Far-UVC light is a type of ultraviolet light that kills microbes and viruses and, crucially, seems to be safe to use around humans. Radiation scientist David Brenner describes how we could use this light to stop the spread of SARS-CoV-2, the virus responsible for COVID-19, in hospitals, nursing homes, trains and other public indoor spaces -- paving the way for a potentially game-changing tool in the fight against the coronavirus pandemic. (This virtual conversation, hosted by TED science curator David Biello, was recorded July 7, 2020.)