Pathogens such as SARS-CoV-2 and pneumococcus can cause severe pneumonia. If the airways then fill with fluid, the patient risks developing acute respiratory distress syndrome. Researchers have now discovered the molecular mechanisms that trigger fluid accumulation in the lungs. This also led them to discover a potential new therapy: A cystic fibrosis drug proved effective in their laboratory experiments, raising hope that this could be used to treat pneumonia regardless of the pathogen that caused it.