Now rats carried this disease off ships in Genoa. In just four years it killed off 40 percent of the people in Europe. It took three forms: "bubonic" plague hit the lymph system, "pneumonic" plague attacked the lungs, and "septicemic" plague assaulted the blood. But the words "Black Death" encompassed it all.

The Church-centered world before the plague had been oddly timeless. Now people worked long hours, chasing capital gain, in a life that could end at any moment. The first new technology of the plague years was time-keeping -- mechanical clocks and hourglasses. Medicine had been a function of the Church before the plague. Physicians were well-paid, highly-respected scholars. They spun dialectic arguments far away from unwholesome sick people -- not unlike some of today's specialists. 13th-century medicine, like the 13th-century Church, had failed miserably in coping with the plague. Both medical and religious practice now shifted toward the laity. Medicine was redirected into experimentation and practical pharmacology. Medical books were now being written -- not in Latin -- but in the vernacular, and by a whole new breed of people.