There is an invisible web of life on Earth, and we are part of it. Microbes are its ancient weavers: they regulate the cycles of the planet and safeguard the health of plants, animals and people. A few are dangerous; many protect us. In the fragile times we are living through, marked by crises of health, climate, ecology and energy, the invisible is part of the threat – but it can also become our greatest ally, provided we pay attention to it and take care of it. Our guide to these discoveries is Antonella Fioravanti, a scientist of international standing who is credited with defeating a super-pathogen that has killed thousands and spread terror throughout history: anthrax. Using a strategy of her own devising – a nanobody able to work its way into the bacterium’s armour and destroy it – she moved science a step forward in the long marathon of curing disease. Weaving the latest scientific findings together with her own story, drawing us into her work as a researcher and looking to the future both as a woman of science and as a mother, Antonella Fioravanti describes the challenges we will face in responding to the impact of climate change on micro-organisms, a field still largely unexplored in which she is a genuine pioneer. This highly original and gripping book is a journey into the microcosm that lives within us and around us, where science, history, biodiversity and wonder intertwine. Because knowing about microbes today is not only a scientific matter but a responsibility towards the planet and humanity. Only by granting them a role in our future can we build a future that is sustainable.