The description of the life cycle of a schistosome continues. The parasites develop and escape from the snail and penetrate the skin of the new host. An example is shown using a mouse. Once in the body, the egg laying begins again. Some observations of schistosomes follow, including the physical transitions they make as they change from free-swimming organisms to parasites in the body. The reaction of the host to the parasite is also described. The narrator sums up the information given in the film and repeats that hopefully new research will lead to a vaccine preventing schistosomiasis.