Mystery of the Black Death

In 1665, a British tailor opened a flea-infested shipment of fabric from London. In a matter of days, the tailor and much of the village were suffering the telltale signs of bubonic plague, the disease that wiped out a third of the European population. 350 years later, an American geneticist is delving into the reasons why some managed to survive the Black Death while others were not so lucky.