Broad-spectrum antivirals are desirable, particularly in the context of emerging zoonotic infections for which specific interventions do not yet exist. Sheahan et al. tested the potential of a ribonucleoside analog previously shown to be active against other RNA viruses such as influenza and Ebola virus to combat coronaviruses. This drug was effective in cell lines and primary human airway epithelial cultures against multiple coronaviruses including SARS-CoV-2. Mouse models of SARS and MERS demonstrated that early treatment reduced viral replication and damage to the lungs. Mechanistically, this drug is incorporated into the viral RNA, inducing mutations and eventually leading to error catastrophe in the virus. In this manner, inducing catastrophe could help avoid catastrophe by stemming the next pandemic.