In the 1960s two FBI agents, Rupert Anderson (Gene Hackman) and Alan Ward (Willem Defoe), travel to Mississippi after the mysterious disappearance of some civil rights workers. The two agents are very different. Anderson, the elder, is an ex-southern sheriff while Ward is FBI trained and by the book. Mississippi is a world of racial tension, segragation, and the Ku Klux Klan. Not only do the agents have to deal with their differences and the silence and hostility of the white community, but also the hostility of the black community as well. As their innvestigation gets under way, the small town where the disappearence occurs remains silent. They finally get a break when the wife of a local sheriff (Frances McDormand) steps forward and becomes their key informant.