In 1542, the world was decidedly pre-modern. It would be at least 100 more years until the invention of the first microscope and over 250 years until the first vaccine. The cause of the black plague, a bacillus called Yersina pestis, wouldn’t be discovered for another 350 years.3 In those days, ‘medicine’ meant blood-letting, drinking ground unicorn horn,4 and consuming concoctions of lead and mercury.

But pre-modern or not, in the fall of 1542, the black plague came to Geneva. At the time, the renowned John Calvin, reformer of Geneva and de facto leader of the Company of Pastors (the group of pastors for the entire city of Geneva), was just 33 years old. The Reformation was just reaching maturity, having been accidentally kicked off by Martin Luther 25 years earlier. Mary I of England (who came to be known as Bloody Mary for burning Protestants at the stake), was still 11 years from the throne.5