Steven J. Ross recovers the forgotten story of Leon Lewis, a Jewish attorney who built a network of spies to infiltrate Nazi and fascist organizations in 1930s Los Angeles. While most Americans dismissed domestic fascism as a fringe phenomenon, Lewis recognized the threat posed by groups that were actively recruiting, training paramilitaries, and plotting attacks against Jewish targets and military installations. Ross, a historian who spent years in archives recovering this story, reconstructs how Lewis recruited gentile agents to join Nazi organizations and report on their plans. The book follows these undercover operatives as they attended meetings, gained leaders' trust, and documented conspiracies that would have seemed unbelievable without evidence. Lewis's intelligence prevented multiple attacks and helped bring prosecutions against fascist leaders, though his work remained largely unknown until Ross's research. The book illuminates the broader ecosystem of American fascism in the 1930s, from German-American Bund chapters to Silver Shirt paramilitaries to sympathizers in Hollywood studios. Ross shows how close some of these plots came to success and how much courage was required to stop them. The story resonates with contemporary concerns about domestic extremism and the difficulty of taking seriously threats that seem too outlandish to be real.