At the height of the Red Scare, Angela Calomiris was a paid FBI informant inside the American Communist Party. As a Greenwich Village photographer, Calomiris spied on the New York Photo League, pioneers in documentary photography. While local Party officials may have had their sus-picions about her sexuality, her apparent dedication to the cause won them over. When Calomiris testified for the prosecution at the 1949 Smith Act trial of the Party's National Board, her identity as an informant (but not as a lesbian) was revealed. Her testimony sent eleven party leaders to prison and decimated the ranks of the Communist Party in the US. Undercover Girl is both a new chapter in Cold War history and an intimate look at the relationship between the FBI and one of its paid inform-ants. Ambitious and sometimes ruthless, Calomiris defied convention in her quest for celebrity.