Meet two extraordinary women — Dee Roberts, based on a real-life single mother who took on corrupt and racist law enforcement officials in Texas and Nicole Beharie, the woman who plays her, who makes one of the most thrilling feature film debuts in years.

Dee is a single mother who lives in the projects. She works as a waitress and cares for her four daughters with the help of her mother (Alfre Woodard), a hairdresser. Her community is constantly being caught up in violent law enforcement sweeps that result in widespread arrests of people too poor, uninformed, and desperate to go to court. The county and state get federal funds based on conviction rates so they push hard, often without any real evidence. And the people who have been arrested, all black and all poor, have no resources to defend themselves and settle for plea bargains, not realizing that the admission of guilt will cut off their welfare payments and right to vote.

An ACLU lawyer (Tim Blake Nelson) arrives in town willing to challenge the district attorney (Michael O’Keefe), but he needs local counsel and he needs a plaintiff — someone who has been abused by the process to file the lawsuit. Only Dee has the courage and passion for justice to challenge the established power in her city.

Thankfully, the film avoids the too-frequent failure of making the white characters the heroes of a civil rights story. In this case, it is in part due to a skillful screenplay by Bill Haney and to Beharie’s star power in a performance of extraordinary sensitivity and fire. She has a mesmerizing ability to convey the mingled emotions of fear and resolve while maintaining sweetness and dignity. Her interactions with the four real-life sisters who play her young daughters feels completely authentic and as she thinks through her choices we feel we can see her weigh every option. The story is a classic American triumph of the oppressed through the court system but Dee is more than a client and a figurehead; she is an essential strategist, coming up with a crucial change of plans at the case’s turning point, and a constant source of inspiration. “After what they done to me, they made it my business,” she tells her mother.

It hits a little heavily on the implications of the 2000 election but wisely puts the story in context so that it is clear that the problem is systemic and not the result of one official or one town. Even more wisely, it keeps the focus on Dee, who as portrayed by Beharie is truly mesmerizing.