This is a popular science book written to help address the panic caused by coronavirus disease 2019 (COVID-19). With illustrated texts, it gives, in plain language, a detailed and precise introduction to COVID-19. The chapters of the book include Microorganisms Around Us, Useful Facts about the Novel Coronavirus, The Immune System We Survive on, Various Factors Affecting Immunity, How to Keep A Well-balanced Immune System, Methods of Preventing Novel Coronavirus Pneumonia and Other Infectious Disease, Psychological Adjustments During an Epidemic, Diagnosis and Treatment of the COVID-19, Rehabilitation of Discharged Patients, etc. From the perspective of health management, the Book strives to help the readers fight through darkness of the epidemic by equipping them with a correct understanding of the situation, basic knowledge in dealing with the spread, skills of self-adjustment and tips of reducing psychological stress.