As World War II raged into its second year, America remained divided on the subject. Canadian-born MI6 officer William Stephenson—also known as Intrepid—was tasked with moving public opinion toward the fight, by any means necessary. Here the author of Agent M shows how Stephenson flooded the American market with propaganda supporting Franklin Roosevelt and decrying Nazism. His chief opponent was Charles Lindbergh—campaigning under the populist slogan "America First"—and the two began a shadow duel with the lives of millions in the balance.