Rotavirus is responsible for more than 130,000 deaths in infants and young children younger than five years, every year. The virus causes severe, dehydrating diarrhea as it replicates in viral factories called viroplasms that form inside infected cells. Viroplasms have been difficult to study because they normally form very quickly, but a serendipitous observation led researchers to uncover new insights into the formation of viroplasms.