A global pandemic rages. In some cities, people shun society completely, while others sit in bars, downing beers and trying to forget about the disease raging around them. But this isn’t 2020—it’s the mid 1300s. The Black Death, which arrived in Europe in 1347, ripped across the continent, killing around 50 percent of its population. Jean de Venette, a French Carmelite friar who documented the pandemic, called it “a most terrible scourge inflicted on us by God.” We now know that it was caused by the bacterium Yersinia pestis, which…