The Kincade Fire has been burning through Sonoma County, displacing people from their homes and leaving destruction in its wake. It is a stark reminder of the increasingly pressing need for a better understanding of how fires begin and spread. This is where Rodman Linn and his research come in. He develops and uses computational models of the coupled interaction between the wildfires and surrounding atmosphere at Los Alamos National Laboratory. In the November 2019 issue of Physics Today, Linn describes a few of the many ways that fluid dynamics controls the behavior of fires.