This book guides through the fascinating world of viruses and makes readers enjoy science in an accessible way. Virologist and author Professor Van Wilson imparts knowledge about what viruses are, how they work, and how much they impact life on Earth. The book equips the reader with the scientific basics behind virus function and presents the historic milestones of virus research and discovery. Well-known viruses such as HIV or Influenza are tackled alongside novel pathogens like coronavirus SARS-CoV-2. Professor Wilson explores where they come from and how they impact our society.  Last but not least the book provides exciting insights into how our immune system reacts to different viruses and how vaccines contribute to conquer pandemics. While scientifically informative, this book makes the field of virology understandable to a lay audience and encourages readers to further thinking. And more importantly, it conveys the wonder, beauty, and mystery of these ubiquitous, microscopic marvels. This book addresses anyone interested in understanding the principles of virology, viral diseases, or the impact of viruses on human societies.