*CUT TO THE CHASE*
NOTE: This spoiler was submitted by Jeremy
The film opens with an animation and text depicting the Great Migration during World War I. After World War II, African Americans had been moved to segregated communities, including Detroit, which contained a mostly white police force. Change was inevitable. It was only a matter of how, and when.
Detroit, 1967 - A party is being held in a speakeasy for a couple of G.I.'s returning from the Vietnam War. All the guests are African American. Police raid the place due to the place not having a valid liquor license. They bring the guests out into the streets to make their arrests public, leading to a crowd of angry onlookers to begin protesting. Once all the guests have been rounded up, one man throws a glass bottle at an officer. Some people in the crowd then proceed to rob a store, thus beginning the 12th Street riots.
Congressman John Conyers (Laz Alonso) addresses the citizens in his community to try and handle the situation involving the police.
The National Guard arrives to patrol the streets of Detroit as the riots continue. One little girl looks out her window to see what is happening. An officer mistakes her for a sniper, leading to the other men to blast through the window.
Three patrolmen - Krauss (Will Poulter), Flynn (Ben O'Toole), and Demens (Jack Reynor) - drive through the streets as the chaos is happening. They find one man, Leon (Tyler James Williams), stealing from a grocery store. Krauss and Flynn chase after Leon. Krauss aims his shotgun at Leon and shoots him in the side. Leon manages to hop a fence and make it to the home of a woman down the street from his house. He lays under her car and asks the woman to get his wife. Police later find Leon dead.
Krauss' superior, Detective Tanchuck (Darren Goldstein), meets with him following the incident with Leon. Tanchuck chastises Krauss for using a gun on an unarmed individual. Krauss tries to play it up by saying MAYBE Leon killed someone during the robbery.
Security officer Melvin Dismukes (John Boyega) watches as an officer harasses an African American teenager. Dismukes goes over to pretend the boy is his nephew to help him on his way home. The boy makes rude remarks to Dismukes, who hits back that if he were to try anything, the other officers would be all over him.
A young man named Fred (Jacob Latimore) arrives at a theatre to join his group, The Dramatics, who are performing after Martha and the Vandellas. The guys are eager to perform before the equally excited crowd, only for an officer to show up to tell the manager that they need to evacuate everyone due to the rioting going on outside. Despite the group's protest, everyone is forced to leave. The group's lead singer, Larry (Algee Smith), starts to sing by himself onstage with nobody but Fred to listen to him.
Larry and Fred ride a bus and head to the Algiers Motel to stay the night. They are placed in a room by the annex. They go to the pool where they meet two white women, Julie (Hannah Murray) and Karen (Kaitlyn Dever). Larry proceeds to flirt with Julie. The ladies invite the guys to another room.
Upon entering the room, the guys meet Carl (Jason Mitchell), Lee (Peyton Alex Smith), and Aubrey (Nathan Davis, Jr.). Carl is dismissive of Larry and Fred. Larry starts to hook up with Julie while Carl cooks hot dogs. They proceed to discuss the ongoing situation in the streets and how the police are dealing with other African Americans. Carl takes out a small pistol and pretends to interrogate Lee. Lee appears nervous and tries to grab the gun from Carl, only for Carl to shoot him. Everyone freaks out, only for Lee and Carl to start laughing, as it was a toy gun. Larry, Fred, and the ladies all go back to their rooms.
Carl sees police officers a few streets down. He intends to scare them with the gun. He shoots in their direction, leading the police to panic and think they are being fired upon. The police and a few sergeants head down to the Algiers and start firing into the rooms before the patrolmen enter the motel. Carl tries to run, only to get shot by Krauss. Krauss then plants a knife next to Carl as he bleeds out. When Dismukes shows up to the scene, Krauss lies and says that Carl tried to attack him with the knife while trying to go for his gun.
The patrolmen round up Larry, Fred, Aubrey, Lee, Julie, Karen, and another man named Greene (Anthony Mackie). The officers force them up against the wall to get them to say who shot at them, who has the gun, and where it is. Everyone is scared and all of them deny knowing anything about the gun. Krauss and Flynn begin to brutally beat the men while Flynn hits Julie in the head with the butt of his rifle. Krauss leads the interrogation and orders everyone to start praying. He takes Lee into the room with the threat of shooting him if he doesn't tell them what they want to hear. Krauss fires a round next to Lee's head and orders him to stay still and be quiet, or the next shot is for real. A sergeant does the same with Greene.
Michigan state police show up as this goes on. They decide to let the patrolmen take this case.
Krauss and Flynn grab Julie, Karen, and Greene to interrogate them in another room. Julie is constantly accused of being a prostitute, and Greene is accused of being a pimp. Greene says he is a veteran from the Vietnam War, though Krauss continues trying to disprove this even after Green shows him his card.
The officers are alerted to commotion going on from outside. Larry and Fred attempt to escape, only to find more officers and sergeants approaching, forcing them to return to the wall. When the officers return, Krauss lets Demens take Aubrey into a room to play their little game. However, Demens isn't aware that this was a game, and he shoots Aubrey for real. Krauss comes in and sees this and becomes worried. He tells Demens to come up with a story of how Aubrey reached for his gun. They then get Larry and tell him he can leave if he never speaks of what he saw. Larry runs away without a word. Fred is brought in next, but when he doesn't comply with Krauss, he shoots Fred twice before Flynn blasts him with a shotgun. Meanwhile, a sergeant lets Lee get away.
Larry runs until he comes by an officer, who sees how banged up he is. The man helps Larry into his car and takes him to the hospital.
In the aftermath of the motel incident, Aubrey's family is informed of his death. His father gathers his son's belongings and heads to the morgue to identify Aubrey's body.
Dismukes is found by police at his warehouse job and brought in for questioning since he has been named a suspect in the motel incident. Two detectives, Thomas (Chris Coy) and Jones (Dennis Staroselsky), interrogate him and suggest he used his revolver to carry out the murders. Dismukes provides a contradictory account of that night, and he is briefly incarcerated.
At the police station, Demens and Flynn admit to Tanchuck over what really went down at the motel. When Tanchuck is ready to talk to Krauss, he tries to get away, only for Tanchuck to find him and threaten him.
The Dramatics visit Larry in the hospital. Fred's brother is there to ask what happened to Fred. Larry confirms the police most likely killed Fred.
Krauss is being interrogated by Thomas and Jones over the incident, but he is pulled out by his attorney, Auerbach (John Krasinski).
The patrolmen are put on trial for the incident. The surviving victims all give testimonies and directly place blame on the officers involved. Auerbach presses everyone at the stand, leading at least one of them to get angry and shout obscenities. The all-white jury finds the patrolmen not guilty of assault or murder. The result is enough to make Dismukes vomit.
The Dramatics get a record deal, but Larry no longer wants any part of it after all he's been through. He takes a small job as a church choir director since all the clubs in the area are patrolled by officers. Larry is then seen directing the choir.
The final text states that Melvin Dismukes left Detroit following multiple death threats, and he has worked security for places like Sears Roebuck. The three officers were found not guilty, but a case was filed against one of them and they were forced to pay a $5000 settlement to the family of Aubrey Pollard. Fred Temple's family sued the city of Detroit for a wrongful death, though the city would not admit guilt. Carl Cooper's gun was never found. Julie Ann Hysell never returned to Detroit. She now has four children and works as a hairdresser. The Dramatics continue to perform to this day, but Larry Cleveland Reed never rejoined the group. He still works as a choir director.