Last January, as heavily populated parts of Los Angeles burned, images of the disaster brought the destructive power of wildfires into the public consciousness more than ever. Today, as thousands of acres burn in the Pacific Northwest and in Canada, wildfire smoke is causing hazy skies and air quality warnings all the way to the Great Lakes and even Florida. But beyond the danger of flames and pollution, what if there’s more in that smoke than we realized—something alive?

Our guest is professor of wildland fire science at the University of Idaho and a pyroaerobiologist, where she is working to uncover a surprising and little-known dimension of wildfire: living microbes, bacteria and fungi. These tiny organisms, pulled from burning forests and soils, are hitching a ride through the air, affecting ecosystems, agriculture, and human health hundreds of miles away.