In this talk, Sonia Shah interweaves history and original reportage to explore the origins of epidemics, drawing parallels between the story of cholera-one of history's most disruptive and deadly pathogens-and the new pathogens that stalk humankind today, from Ebola and avian influenza to drug-resistant superbugs. Over 300 infectious diseases have newly emerged or re-emerged in new territory over the past 50 years, and 90% of epidemiologists expect that one of them will cause a disruptive, deadly pandemic sometime in the next two generations. To reveal how that might happen, Shah tracks each stage of cholera's dramatic journey from harmless microbe to world-changing pandemic, from its 1817 emergence in the South Asian hinterlands to its rapid dispersal across the 19th-century world and its latest beachhead in Haiti. She reports on the pathogens following in cholera's footsteps, emerging from China's wet markets and the surgical wards of New Delhi to the slums of Port-au-Prince and the suburban backyards of the East Coast. By delving into the convoluted science, strange politics, and checkered history of one of the world's deadliest diseases, Shah reveals what the next contagion might look like-and what we can do to prevent it.