In 1932, the U.S. Public Health Service began recruiting Black sharecroppers in Tuskegee, Alabama, for a study on untreated syphilis, and kept enrolling and misleading them for the next forty years. Of the 600 men involved, 399 already had the disease and 201 did not, and none were told the truth: they were led to believe they were being treated for "bad blood," a catchall local term covering everything from anemia to fatigue. In exchange for free meals, medical exams, and burial insurance, they went untreated even after penicillin became the standard cure for syphilis in the 1940s. The film traces the arrangement between the Public Health Service and the Tuskegee Institute that kept the study running, and lays out the poverty and segregation that made the men easy to recruit and easy to ignore. It follows the study to its exposure in 1972 and the record of a forty-year government program built on lying to the people it claimed to be helping.