Tuberculosis has shaped human history for thousands of years, but today it is often treated as a disease of the past or a tragic reality only for the global poor. John Green takes you on an urgent, deeply personal journey to understand the world's deadliest infectious disease. His perspective shifted dramatically after meeting Henry Reider, a young tuberculosis patient in Sierra Leone with a wide smile and spindly legs. Through Henry's deeply human story, Green unwinds the scientific facts, historical impact, and social inequalities that allow a preventable and curable illness to claim over a million lives every single year. You will discover how global healthcare systems succeed and fail, and why the choices we make today are critical to stopping this ancient killer. This powerful narrative bridges science and empathy, challenging you to look closely at the inequities that define our modern world.