In July 1518 a mysterious and terrifying epidemic struck the city of Strasbourg. Hundreds of men and women began dancing wildly, day after day, in the punishing summer heat. They did not want to dance, but could not stop themselves. Throughout August and into September more were seized by the same compulsion; by the time the epidemic subsided, heat and exhaustion had claimed an untold number of lives. The author of The Real Oliver Twist and The Discovery of the Germ, medical historian John Waller gives us a gripping account of this seemingly fantastical event, explaining why the dancing plague took place while evoking the sights, sounds, aromas, hardships, fervent supernaturalism, and the desperate hedonism of the late medieval world. The extraordinary story offers rich insights into how people behave when driven beyond the limits of endurance, the strange capabilities of the human mind, and the extremes to which fear and irrationality can lead us.