Businessman Matt McGreevy is driving home in the rain after a late night. He's driving through a poorer part oft own and talking to his wife Hilary. He hears someone yelling and hangs up, and a black man runs up to his car bleeding from a cut on his forehead. He pounds on the car window and asks Matt for help. However, Matt locks his doors and drives away. As Matt looks back, he sees men emerge from the shadows and viciously beat the black man.
When Matt arrives home, his wife asks him where he's been. He goes to the bathroom and discovers there's a cut on his forehead. Hilary tends to it and says that the black man was probably a carjacker, but Matt isn't so sure. He goes to bed but the next morning wakes up in pain and discovers bruises on his body. He reads the morning paper and sees an article on the dead man: John Woodrell, a college professor rather than a carjacker. Matt stops for a morning coffee with his friend Donnie and admits that he feels guilty about what happened. Donnie says that he couldn't have known and asks if Matt would have stopped if the victim had been a white man. Matt defensively says it wouldn't have made a difference and Donnie notes that then he can't be a racist, and he should get on with his life.
Matt continues to work where he draws odd stares from the people there. Finally his secretary gives him a mirror and shows him that his skin is turning darker. Matt goes to Dr. Lisker who says that Matt isn't suffering from any disease or illness, and has the normal pigmentation for a half-Caucasian/half-African American individual. Matt denies having any such parentage and Lisker wonders if he's nut. Matt goes home but when he comes in the house he has transformed completely… into John Woodrell. Hilary thinks he's an intruder and runs out to get a neighbor, while Matt's dog tries to attack him. Matt runs outside but the neighbor shoots at him and Matt barely gets away in his car. He goes to a hotel but the desk clerk won't admit him without an ID, and Matt only has an ID with his original photo on it. When the police come looking for his car, which they think is stolen, Matt is forced to abandon it and slip out the back.
As he wanders the streets, unable to get a cab because of his skin color, Matt sees a newspaper with a picture of Woodrell and goes to the professor's house. Woodrell's father-in-law Thomas greets him and at first thinks he's John, returned from the dead. Matt tries to explain what happened. He's come to the house hoping that John's wife Clare will forgive him for his mistake, allowing him to transfer back. Clare has overheard the entire thing and has one question: would Matt have abandoned a white man. Matt can't answer and Clare and Thomas go inside, leaving him alone.
It starts to rain and Matt wanders the streets with nowhere to go. Three men, white separatists, attack him. Matt manages to escape and runs into the street… where he runs into the car driven by Matt. Matt pulls away again, leaving, John to his fate… until he reconsiders. Matt backs up and rescues John, and gets away from his attackers. As they leave, John wonders why Matt came back. Matt admits that he considered leaving, but then realized what it would be like if he was the man being beaten.