This book is about clinical thinking, the relationship between the doctor and instructions, and cooperation with the patient. How should you think at the patient’s bedside, analyze sources, authoritative opinions, see both the patient and the pathogenesis of his disease behind the diagnosis, how to become a truly good doctor? These and many other questions will be answered by Andrei Sokolov, the creator of several Moscow clinics, a doctor, and the author of several scientific and popular science books. Also in this book you will find exercises for the development of clinical thinking. This exciting detective story about medical tricks is written based on real examples from the practice of the author and his colleagues. The book will be useful and informative for both doctors and non-specialists.