Fungi are key organisms that keep the material and energy cycle of nature going. They can live in symbiotic or parasitic communities with plants and insects and are mainstays of the biotechnology industry. As pathogens, they infect plants, animals and humans, producing toxic substances as well as life-saving drugs. Their exploration as potential suppliers of future food, industrial materials or textiles underlines the fact that the process of making these organisms useful to humans is far from over; perhaps it has not even really begun. Although fungi can form tissue-like growing cell filaments or even clearly visible fruiting bodies, like bacteria or microalgae, they belong to the group of microorganisms that can only be recognized as individual organisms with the aid of a microscope. To date, around 120,000 species of fungi have been scientifically classified, and yet they are among the least studied living organisms. According to the latest estimates, 99% of fungal species are still unknown, and the gene sequences of only 30% of the described species have been published [1]. Since knowledge of bacterial diversity is no better, the most extensive terra incognita of our planet is the domain of microbes. The following account is about one of the most extraordinary protagonists of this microcosm, the ergot fungus.