A Student’s Guide to a Drop of Water is a brand-new atlas of microorganisms designed mainly for use in primary and secondary schools. It features illustrations of more than 400 species divided into five categories: Prokaryotes, Algae, Heterotrophic Protists, Plants, Fungi & Animals, and Abioseston. The Guide leads both students and teachers through the most common organisms and objects found in a drop of fresh water. Concise and with just a light touch of theory, it is filled with digital artwork created to capture the actual appearance of the organisms as faithfully as possible. Much like the iconic Hitchhiker’s Guide to the Galaxy, to which its title playfully nods, it aims to guide users through a diverse “microcosm” with playfulness, colour, and some reassuring advice at the end: Don’t Panic. The Guide contains 10 pages of theoretical introduction, 53 pages of microorganism overviews arranged in taxonomical or morphological groups, and 10 pages of sample examples from various habitats. In total, it includes 582 colour illustrations.