Sam finds himself in a diner in the Deep South. He casually sits down and gets something to eat. Everyone looks at him in shock and Sam looks into the mirror to realize he's an elderly black man. Two local boys come over but the waitress intervenes and tells him to take Miss Melanie's lunch to her.
Outside, Sam finds Miss Melanie calling to him from across the street. She identifies him as Jessie Tyler, her black chauffeur. He claims that he's had trouble remembering things since a head injury, and Miss Melanie tells him that they're going to see Charles and gives him directions. As they drive, Sam realizes that Charles is Melanie's dead husband. They drive over the railroad tracks and arrive at the cemetery. Sam helps her to her husband's grave and she desperately starts clearing the weeds. Sam insists on helping her and Melanie talks about how she and her husband took care of each other after they lost their son Beau. She mentions that Jessie's wife lost four children before she died herself.
As Sam throws the weeds in the trash, Al appears. Sam notes that the possibilities are limitless if he can leap into a black man, but Al warns that it's a dangerous time to be a black man. He explains that Melanie was killed when her car was struck by a train at the railroad crossing by the cemetery. Ziggy has been unable to find data on Jesse, including whether he was killed with Melanie. Al remembers that some of the freedom protests started in the area, and he was there marching and gotten arrested and beaten with others. Sam wonders if he's there to be involved with the civil rights movement, but Al isn't convinced.
Sam drives Melanie home, where her son Clayton is waiting. He's there to talk to Jesse privately. They go to the kitchen and Clayton warns that he upset the entire town by sitting down at the diner. He wonders where Sam got such a stupid notion and Sam starts to angrily move toward him. Clayton backs nervously away and Sam recovers himself. Clayton goes to talk to his mother, who insists that whatever Sam did doesn't matter. He warns her that she's the widow of the state governor, and other Negroes might get the wrong idea. When he asks if she'll be responsible if other Negroes step out of line, she ignores him and he leaves. Once he's gone, Melanie clutches at her head and calls for Sam. Sam checks her vision and she wonders where he got a medical degree and tells him to leave her alone and get a glass of lemonade.
As Sam gets the lemonade, Jesse's granddaughter Nell comes to the back door and says that she's proud of him. Sam goes back and checks on Melanie, who tells him not to worry about her and to let Nell take him home. As Nell drives Sam home, she brings up the diner incident and wonders what it felt like. Nell wants the white folks shook up. As they drive, the two men from the diner follow them home from a distance. Nell gets him home to cook chitlins for the church picnic. Al appears to talk him through the cooking while his daughter, Ellie, and son, Reverend Willis, leave.
As Al goes over the recipe, Willis comes back and wonders why Sam is talking to himself. He worries about Sam sitting in the diner and Al admits it's a problem. Willis asks Sam not to sit at the diner any more and leaves. Once he leaves, Al warns that he doesn't have a right to sit at the lunch counter in 1955, and doesn't want him to get sidetracked from saving Melanie. Sam angrily insists that what they did was wrong. Before they can pursue the matter, the two men from the diner, Toad and Billy Joe, burn a cross on the yard and drive away, laughing.
The next morning, Sam goes to the sheriff but he says he doesn't plan to do anything and tells Sam to forget about it. The sheriff says he'll talk to his son Billy Joe, and warns that what happens next is up to Sam. Sam inadvertently goes to a white-only fountain and Billy Joe and Toad see him, but Billy Joe says that they'll deal with him later.
Sam goes to see Melanie and fix her sink. He doesn't have much luck and Melanie invites him for tea. However, when he tries to sit down with her, she points out that she can't have tea with him because coloreds and whites don't eat at the same table. When Sam points out that it's okay and it's time to change, Melanie hesitates and then tells him to answer the door when someone knocks. Sam finds Nell at the back door. When he says he'll be driving Melanie's car home, she wonders what he's up to. She leaves for choir practice and Melanie tells him that his idea of equal rights and changing things is hogwash. Sam insists that blacks are going to unite and she wonders if he's gone crazy.
As Nell drives to choir in her father's car, Billy Joe and Toad spot her and decide to teach Sam a lesson. They pull out and she goes off the road and down a hillside. Toad tries to check on her but Billy Joe insists on driving off.
Sam tries to convince Melanie that she can lead by example, but she refuses to discuss the matter. She tells Sam to go into town and get a pipe for the sink, and insists on going. Sam tries to talk her out of it but she refuses, and he insists on driving her. As they drive into town, they spot Willis' car off the side of the road. Sam tries to treat Nell for her head laceration but he needs to get her to the hospital.
Sam drives Nell and Melanie to the hospital but the staff there insists that it's for whites only, and the colored hospital is too far away. Melanie steps in and tells the doctor to treat Nell on her authority. She tells Sam to stay outside while she makes sure that Nell is treated properly. As Sam waits, With 23 minutes left until Melanie's death, Al appears and tells him to get Melanie to safety. Before Sam can do anything, the sheriff arrives to arrest Sam for breaking the segregation law. The nurse confirms that Sam has been talking to himself and he's crazy. Sam agrees to go if the nurse promises to keep Melanie there for 30 minutes. The nurse agrees, but once Melanie comes out, she insists on driving after the sheriff and having him arrest her as well. Al tries to object but Melanie can't hear him.
With time running out, Al has Ziggy center him on Melanie. He tries to get through to her without success, and she can't hear the train whistle because of her poor hearing. As they arrive at the crossing, Melanie suddenly pulls off into the cemetery. She believes her dead husband Charles was talking to her.
Al goes to the jail and contemplates the possibilities of communicating with woman. He confirms that Jesse is still alive in their present, and Sam wonders why he's still there. Sheriff Blount arrives to release Sam at Melanie's request. He admits that Billy Joe tried to teach him a lesson, and promises that no one will both Jesse or his others again. Al assures Sam that in four months, Rosa Parks and Martin Luther King will start the Alabama boycotts. As Sam goes, he warns Blount that soon he'll have to change his mind about a lot of things. Back in the cell, Al remembers being arrested and sings "We Will Overcome."
Outside, Sam finds Melanie and Clayton waiting. Clayton accuses Sam of using his mother, but Melanie tells him to mind his own business and sends him off. She tells Sam that Nell is fine but has been moved to the black hospital. She wants things to go back to normal, but Sam says things can't go back. Melanie admits that she knows things aren't just, but things can't change. She tells him that if he wants to continue working for her, they won't discuss it any further. She tells him to go to the diner and get her lunch.
Sam reluctantly goes into the diner and everyone looks at him expectantly. He goes to the counter without sitting and gets Melanie's lunch. However, Melanie comes in and says that she'll eat there... and invites Sam to join her. Billy Joe tries to intervene, but his father tells him to sit down and shut up. Sam sits down, smiles... and leaps.