I was the one who first told Ashley the story of the dancing plague. The plague started with a woman, naturally, named Frau Troffea, who on a clear summer morning in Strasbourg in 1518 began dancing in the street. Neighbours gathered to laugh and clap and cheer her on. But it soon became clear that something was wrong. Frau Troffea danced and danced for six days without stop. Her husband and children brought her water, and shoved pieces of bread and cheese into her mouth to keep her alive, for she wouldn’t even stop to eat; and as discreetly as possible, they did their best to clean her whenever she soiled herself. By the end of the first week, more than thirty others had joined Frau Troffea, and by the end of the first month, there were four hundred dancers, most of them women. Some of the dancers dropped dead in the street, sweaty and red-faced, from exhaustion and strokes and heart attacks. At the height of the mania, around fifteen people were dying each day. The doctors of Strasbourg ruled out astrological or supernatural causes, and instead attributed the dancing to ‘hot blood.’ Some prescribed bleeding, but others suggested the only cure was for the afflicted to dance day and night until they had danced out their mania. So the city gave over two guildhalls and the grain market to the dancers, and when these spaces filled up, the city hired a band of musicians and built a giant outdoor stage. But, perhaps unsurprisingly, this only encouraged more people to join in. Soon, people from all across the land were pouring into Strasbourg to dance to their deaths. It is still not known why the mania began, or how it ended.

While writing this book, the obvious question that struck me was—Whatever happened to Frau Troffea? I could find no mention of her fate in any article, despite nearly every single one identifying her as the first dancer. A few details also differed from my memory of the story. Like for instance, there’s not a single mention of her husband and children bringing her food or cleaning up her shit as she danced. I suppose that was my own hopeful invention. I did, however, find an image of an engraving by Hendrik Hondius from 1624 called Dancing Mania on a Pilgrimage to the Church at Sint-Jans-Molenbeek. Hondius based his engraving on a drawing made nearly eighty years earlier by Pieter Bruegel the Elder, who had been a witness to the events.