Between Joanna’s trial in March and late spring, when he fled to the papal retreat at Etoile-sur-Rhône, the pope spent a great deal of time seated between two roaring fires in the papal chambers. The fires were the idea of surgeon de Chauliac, who believed heat would cleanse the papal chambers of infected air, thought to be the cause of the pestilence. And the treatment worked, though for reasons that would have surprised the surgeon: the fires kept the papal chambers free of infected fleas.
