In 1573, the alchemist Anna Zieglerin gave her patron, the Duke of Braunschweig-Wolfenbüttel, the recipe for an extraordinary substance she called the lion's blood. She claimed that this golden oil could stimulate the growth of plants, create gemstones, transform lead into the coveted philosophers' stone—and would serve a critical role in preparing for the Last Days. Boldly envisioning herself as a Protestant Virgin Mary, Anna proposed that the lion's blood,...