A century ago, the greatest pandemic since the Black Death engulfed the world. From spring 1918, a deadly form of influenza rapidly developed and struck hundreds of millions of people. By spring 1919, it had left 50 million dead. This book charts the enduring legacies of that cataclysmic year and tells the story of what happened after 1918. Not only did the pandemic haunt the individual and collective memories of survivors, it became a touchstone for generations tasked with protecting the health of nations and the international community.