At the dawn of the eighteenth century, England was running out of money due to a prolonged war with France. They turned to the stock market. In the hub of London’s stock market—Exchange Alley—the South Sea Company hatched a scheme to turn the national debt into shares of company stock, and over the spring of 1720 the plan worked brilliantly. Unlike science, though, with its tightly controlled experiments, the financial revolution was subject to trial and error on a grand scale, with dramatic, sometimes devastating consequences for people’s lives. With England at war and in need of funds and “stock-jobbers” looking for any opportunity to get in on the action, this new world of finance had the potential to save the nation—but only if it didn’t bankrupt it first.