In the 21st century, we are all connected. Population growth, mass urbanization, deforestation, climate change and increased travel have dramatically increased the risk that familiar diseases will spread and mutate, and new ones will emerge. Unseen Enemy is an essential exploration of reasons 21st-century populations are experiencing a rash of diseases that were once only outbreaks, but have now become full-blown epidemics.

This increased risk that we face is examined through the case studies of three epidemics: Ebola, influenza and Zika. Moving across the globe, we meet doctors, disease detectives and everyday people who have stepped into the horror of an epidemic and emerged deeply changed. Epidemics bring out the best and worst of human behavior, with effects reaching far beyond the tolls of sickness and death.