The years 1347 to 1350 were the peak of the Bubonic Plague phenomenon. Its impact on Europe's population in those years were so great that the exact death toll varied. Some sources claimed that one European out of four fell victim to this pestilence, while others say that half of Europe died off.

In this alternate scenario, the Black Death was even more severe to the population of Europe. Some would say that one European out of three *survived* the pestilence while others would say it was one out of four.

With an increased severity in the plague, how would this affect the culture, society and history of Europe? Could a rat flea have still carried such a disease, or would such damage come from a different species of invertebrate better capable of inflicting such virulence?