Emma and Lionel are a young black couple who live in 1960s Louisiana with Emma's elderly mother Willie Mae. Willie was a midwife and doctor for many years in the town, and she has helped many of the white townspeople. Lionel tells Emma and Willie that a new law has been passed that allows them to vote, and he argues that they need to show white people that they cannot keep black people from voting. Emma objects, as she does not think it is worth the risk. Willie's husband was lynched years before, and Emma is afraid of that risk nearing the familiy again.
Finally, Willie speaks up. She is very old, and does not have much time left to live, so she decides she wants to vote before she dies. Lionel explains that she must hunt down the registrar who stays hidden, take a test, and be of good character. For the next week, Willie sits outside of the courthouse in her rocking chair, waiting for the registrar Fat Tommy to come into work. One day the sheriff comes up to her and threatens her, but Willie threatens to tell the whole town that the sheriff's mother wanted to drown him when he was born. The sheriff is angry, but tells Willie that Fat Tommy is inside. Willie goes insides, and successfully registers to vote. 
The night before the vote, the family hears cars zooming into their front yard. Willie tells Emma to hide Lionel in a hiding space she had built behind her closed after her husband was lynched. The women go outside, where many townspeople wear white caps and robes. The sheriff tells them to send Lionel out, but they insist that he is not there. The men search the house and trash it, but cannot find Lionel. Once the men leave, Willie tells Emma that Lionel must stay hidden for the night, and then he must sneak out of town.
The next day, Emma drives Willie to the polls. Outside the courthouse, crowds of black people are waiting to see the first black person vote in their town. When the woman reach the front door of the courthouse, the sheriff calls out Willie's name. He is standing behind them with a gun to Lionel's head. Emma is screaming and falls to the ground. Willie looks into Lionel's eyes, and sees that he is calm. He nods at her, and she knows that he has accepted his fate. Willie turns to step into the courthouse, and as soon as she does, a shot rings out. Willie thinks about all of the black voters who will come after her, and she thinks that "one bullet, one vote" is the price they must pay.