The author traces Peters's activities from his arrival in the United States to the dawn of the Cold War and his deportation back to Hungary. Known as the "Hungarian man of mystery," Peters emigrated to the United States in 1924 after serving in the Austrian Army during World War I. In America, he oversaw a false passport operation that facilitated the movement of Soviet agents to the United States and American communists to the Soviet Union. Working under a number of aliases, he constructed a complex network of informants and spies that stole numerous State Department documents in the 1930s. After years of hiding underground he was arrested and deported in 1949. The author reveals Peters to be not just the influential leader of conspiratorial Communist activities but also an organizer in the open American Communist party. The author of a handbook on Communism, Peters also set up a program to infiltrate the armed forces in the United States.