The highly contagious disease smallpox was a frightening scourge throughout history. Up to 1959, 50 million people each year became infected with the disease. Not only did it leave terrible scars on those that were lucky enough to survive but it weakened the body and left the afflicted vulnerable to yet more deadly complications. Readers will learn about the biology of the smallpox virus, historical figures who contracted it, and the massive vaccination campaign that eradicated smallpox in just 10 years, giving us hope that a similar approach may help eliminate other fatal diseases.