Bacteria are often thought of as our enemies - tiny primitive cells ("germs") that multiply by rapid rounds of division, causing disease and food spoilage. This view of bacteria is certainly not true of soil-living Streptomyces bacteria: although their spores are tiny, they grow into multicellular organisms easily visible without a microscope; and they are extremely useful to us. Their usefulness comes from their amazing virtuosity as chemists - as they make many of the antibiotics that we use to treat disease. Many species of Streptomyces have been captured by the pharmaceutical industry and bred for this purpose. Previously, we could describe these marvellous bacteria mainly in terms of what we could see or detect from the outside. In this lecture, Keith Chater will present a new view of them, made possible by their complete genomes. Paradoxically, this view from the inside has revealed that there are many ways in which thier lives extend outside the confines of their cells.