The program opens with a film visit to the National Institutes of Health labs in Bethesda, MD. Dr. Tomlinson explains the life cycle of schistosomes via snails to humans. Dr. Wright describes the characteristics of the disease and shows films of victims of the parasite. He also explains how U.S. troops fighting in the South Pacific could bathe in infested streams and bring the parasite to the U.S. unless they use chemical repellants on their clothing and body. Dr. Cram describes her team's search for a U.S. snail that could serve as a host for schistosomiasis. The NIH schistosomiasis snail study collection from around the world is displayed. Dr. Nolan describes her search for a safe chemical compound to pour into waterways to kill snails on a large scale, and she demonstrates how it works.