In Center City, bus service has been discontinued because of increased violence in the predominately black community. Most recently, Joe Mitchell, a black, non-violent civil rights leader was killed in his own home by an unknown assailant with no apparent motive. Joe's brother Billy returns to Center City after serving in the Vietnam War, just in time to attend the funeral, where he witnesses militant Black Fist leader Michael inciting the crowd to rally against the "pigs" or police, whom he blames for the crime. Furious that Michael is using the funeral for his own political purposes, Billy confronts him and refuses to sign Michael's protest rally application. Meanwhile, bigoted police sergeant Tim Naylor decides that he and his partner, Corie Smith, will intimidate Billy to keep him from investigating his brother's death. At Black Fist headquarters, Michael reminds his group that the local school has been refused the right to integrate, asserting that Joe Mitchell was murdered because of his support of integration. When Michael vents his frustration that Billy will not fight against the police, Michael's sister Tanya counters that Billy, her old boyfriend, has not adjusted to civilian life yet. At his apartment, Billy talks with his white army buddy John, who suggests that instead of joining the Black Fists, Billy should find evidence to bring the real killers to justice. Lacking faith in the system, Billy dismisses his suggestion. Later, while Billy renews his relationship with Tanya, John is severely beaten by Michael and Black Fist member Dobie for turning Billy against them. When Billy returns, a bruised John tells him that the Black Fists think all white people are evil and decides he must leave the neighborhood for his own safety. The next day, Billy finds a broken headlight and tire tracks behind Joe's house and deduces that the car belonged to Joe's murderer. He then speaks with the only witness to the murder, black schoolteacher Miss Nickerson, who is secretly having an affair with Naylor and calls all black people "liars." Nickerson has told police that she saw Joe pull out a gun to shoot first and did not see Joe's killer. Knowing that Joe tried to have the racist Nickerson removed from the school board, Billy accuses her of conspiring with the killer in order to seek revenge. Later, Naylor tries to refuse Michael and Dobie a rally permit, but Chief Jackson intercedes, gives them the permit and orders Naylor to guard the rally. Back in the teachers' lounge, after both black and white teachers voice their support for integration and complain that their school lacks basic services, Nickerson vehemently insists that they are pandering to the black children and integration is not necessary. At Black Fist headquarters, Billy confronts Michael about abusing John, but Michael ignores his protests and shows him their firearms as proof that they are ready to fight the police. Suddenly Naylor and Smith break into the headquarters, knock out Billy and hold everyone else at gunpoint. Sure of certain death if Naylor is provoked, Michael does not reach for his firearms, despite Naylor holding his gun to Dobie's head. Suddenly, Naylor randomly shoots in the air, wounding Michael, and then flees with Smith. Meeting Nickerson later, Naylor hands her a gun and orders her to kill some blacks for him when the "war" starts. Meanwhile, Billy, feeling betrayed by his country, throws a bottle at the image of himself in uniform reflected in a shop window. As the glass shatters, Naylor and Smith, who have been following him, immediately seize and harass Billy but then release him hoping to catch him committing a larger crime. Later, Jackson interrogates Naylor about the Black Fist headquarters shooting, but Naylor is contemptuous of Jackson for not supporting his efforts to stop the blacks. Later, the Black Fists bomb a police car and Naylor jails Billy for the crime. Tanya is horrified that her brother is allowing Billy to be blamed, but Michael believes Billy deserves the jail time for having foresaken the neighborhood for the military. Desperate, Tanya tells Jackson that she has witnesses that can prove Billy was not at the bombing, demands his release and suggests that the real perpetrators are willing to negotiate for peace if Jackson removes the "lunatic" Naylor from the force. After Michael and Dobie meet with Black Fist members to discuss turning themselves in, they spot Naylor and Smith following them. Fearing for their lives, they flee in their car and hide in an abandoned building. Naylor calls in state police and fires into the building, but when the officers are unable to locate the fugitives, Naylor abandons the chase. Michael and Dobie then admit their guilt to Jackson and insist that he get rid of Naylor. Jackson then questions Naylor about his racist attitudes and orders him to release Billy or risk being fired. After his release, Billy learns that Smith wrecked his car recently and goes to Hoard's body shop with Tanya to look at the vehicle. As they deduce that the damage to the car matches the crime scene evidence, a drunken Smith, who has followed them there, pulls out a gun to kill Billy, but Billy knocks the gun from Smith's hand and pummels him unconscious. Later at the station, when Smith is questioned about Joe's murder, he admits that he and Naylor entered Joe's house without permission and shot him, stating that Naylor insisted on making the murder look like Joe was shot for resisting arrest. Meanwhile, Naylor convinces Nickerson that he is being "framed" for Joe's murder. On the day of the rally, Michael preaches to the crowd that their rights cannot be denied and suggests that when their anger turns to violence, the police will use it as an excuse to retaliate. Proud of the rally's peaceful spirit, Billy takes the microphone to speak, but Nickerson shoots him. As the angry crowd turns toward the police, Naylor orders his men to shoot at them, but the officers refuse to follow his orders. When Naylor refuses to step down on Jackson's command, the chief is forced to shoot him. With Billy only mildly wounded and peace restored, bus service and the hope of integration returns to Center City.
