This book proves that behind dry lines of a biology textbook there are thrilling stories—hypotheses, arguments, coincidences, and discoveries. Its author, biologist and medical journalist Daniil Davydov, reveals the tangled process of medical discoveries made in the 20th and 21st centuries. Did you know that an internal organ can disappear from an anatomical atlas for several centuries? Or that another organ remained overlooked for a long time and was discovered only a few years ago? And the brain still hides many secrets, and its structure looks like a real treasure map. The author will take you on an exciting tour through historical eras and the human body—and explain step by step how scientists, knowledge, and science itself grew.