Bigger fights a rat in his apartment and kills it, then scares his little sister Vera by swinging the dead rat over her face. He leaves the house as he’s being nagged by his mother to take the job he’s been offered by the relief office or else the family will be cut off and will starve.
Bigger spends the day messing around.
First he makes plans with his friends Gus, Jack, and G.H. to rob Blum’s store. Blum is a white man so they decide to bring guns and meet back up at 3 p.m. for the robbery.
In the interim, Bigger goes to the movies and sees a clip about Mary Dalton, who happens to be the daughter of the man offering Bigger a job. He discovers that she’s dating a Communist and rebelling against her parents.
Gus is late for the gang’s rendezvous, so Bigger starts a fight with him, claiming it’s too late now for them to rob Blum and it’s all Gus’s fault.
After the fight, Bigger goes to his job interview at the Daltons’ house. He meets Mr. Dalton, gets the job, and then meets Mary Dalton, who starts asking him if he belongs to a union. She embarrasses him and he’s worried that now he’ll lose his job because of her.
His first task is to drive Mary to the university that night. His second task, he’s informed, will be to take Mary to the train station in the morning because she’s leaving for Detroit.
Instead of going to the university, Mary directs Bigger to another place, where she meets up with her boyfriend, Jan Erlone. She introduces the two men to each other, then directs Bigger to let Jan drive. The three of them sit up in the front of the car.
Bigger feels nervous and ashamed, sitting up front with these two white folks. He thinks they’re making fun of him.
They talk to him about Communism and then ask him if he’ll take them to eat at a place on the South Side, a place where "real" black people eat. So he directs them to Ernie’s Kitchen Shack, where, despite his obvious reluctance and embarrassment, they insist he come inside and eat with them.
The three of them start drinking liquor, and continue the night in the car, drinking.
Bigger drops Jan off and drives Mary home, where she’s too drunk to get to her room by herself. Bigger ends up helping her up the stairs and into her room.
While he’s helping Mary to bed, blind Mrs. Dalton wanders in the room, wondering if Mary’s home and safe.
Caught in Mary’s room, Bigger is afraid that Mary will give him away. To keep her quiet, he puts a pillow over her mouth and accidentally smothers her to death.
After Mrs. Dalton leaves, Bigger discovers that he’s just killed a drunk white girl. What’s he going to do? He decides to stuff her body in her luggage trunk and carry the trunk downstairs.
Downstairs, near his bedroom, he sees the furnace and decides the best solution is to burn her body.
Bigger starts to shove her body in, but the shoulders won’t fit so he has to hack off her head with a hatchet, which he also tosses in the furnace with the body.
When he sees Mary’s purse, he makes sure to take it with him and it turns out to have a lot of money in it.
After cleaning up to make sure there’s no evidence left, Bigger heads home to his family’s apartment, where he sleeps for a few hours.
When he wakes up, Bigger packs his suitcase to live in the Daltons’ house, and heads back.
He plans his story: Jan is at fault. When he left, Mary and Jan were together but told him to take the trunk downstairs.
Bigger returns to the Daltons’ house, eats breakfast, and takes Mary’s trunk to the train station. Mrs. Dalton is clearly worried and wonders where her daughter is.
Bigger takes a nap, then goes to see Bessie in the afternoon.
Bessie and Bigger make love and Bigger feels better. He tells her about how the Dalton girl is missing and they should write a ransom note and get some money out of the situation. Bessie guesses that there’s more to the story than Bigger is telling and asks him if he did something to that girl. Bigger doesn’t tell her yet.
Back at the Daltons’ house, Mr. Dalton has found out that Mary never arrived in Detroit and her trunk has never been claimed. So he’s hired a private detective, who questions Bigger about what happened last night. Bigger knows he could run away at any time, but he wants that money, so he answers the questions, carefully making them all point towards Jan each time.
The private detective, Britten, brings Jan to the house, and Jan asks Bigger why he’s lying.
Bigger leaves the house to arrange the ransom note and runs into Jan, who confronts him again about why he lied. Bigger threatens Jan with a gun and then runs off.
Bigger writes a ransom note and shoves it under the Daltons’ front door. It’s soon discovered and Mr. Dalton calls in the police, but not before the media shows up.
Bigger continues to answer questions as they come. He wonders if he should leave, but he doesn’t because all suspicion is directed at Jan, and Bigger wants the ransom money.
But finally, he’s undone. Peggy comes to tell Bigger he needs to sift the ashes in the furnace because the fire is almost out and it’s cold. So he starts to spread the ashes around and only succeeds in making the whole room smoky. A journalist takes over and discovers bones and an earring – Mary’s remains.
Bigger escapes through the window of his room.
He heads straight to Bessie’s place and coerces her to run away with him. They take the money that’s left from Mary’s purse and go find an abandoned building to sleep in.
Bigger forces Bessie to have sex with him and then he makes a decision. Bessie is clearly not interested in running away with Bigger. She’s nervous and scared. But he can’t leave her behind, either, because she’ll tell the police everything. So he kills her instead, smashing her chest with a brick.
When Bigger thinks Bessie is dead, he stuffs her body in an airshaft. That’s when he realizes she has the money in her clothes but he decides he can live without it.
Now Bigger is on the run. Police have been called out to find Bigger and they’re systematically searching every apartment and house on the South Side. Bigger moves from place to place but eventually, they catch him on a roof.
In jail, Bigger numbs himself. He doesn’t eat or drink or talk or think or feel. He just exists and then he faints at the inquest.
The Reverend Hammond visits and tries to comfort Bigger through Christian theology. He gives Bigger a little wooden cross to wear around his neck.
Jan visits and tries to convince him to accept the lawyer that Jan has arranged for his defense, Mr. Boris Max.
Mr. Buckley, the State’s Attorney, visits and convinces Bigger to sign a confession.
His mother visits and shames him in front of the Daltons, who also visit.
At last, he’s alone again. He wonders if he should trust Jan’s offer of friendship, but mostly he tries not to think too much.
The police come and take him to the rescheduled inquest.
When the inquest is done, he’s taken to another prison. On the way, the police stop at the Daltons’ house and try to convince Bigger to show them how he raped Mary, which he didn’t do. Bigger refuses to show them anything.
As they leave the house, Bigger realizes just how much people hate him. The mobs are there, trying to get at him. The Ku Klux Klan is burning a cross.
In prison, Max comes to visit and Bigger tries to explain to him how and why Mary ended up dead. Max says they’ll plead guilty to avoid a jury trial but then he’ll try to convince the judge to give Bigger life in prison instead of the death penalty.
Bigger’s thoughts are largely absent at the trial. He has a moment of revelation when he makes it to the table before Max and realizes how much he’s come to depend on Max, that Max is what stands between him and the mob.
When Bigger receives the death penalty, it’s a blow deeper than he realizes. He goes back to his cell and tries to mark time until the day. Though Max says he’ll try to get the governor to grant a stay on the death sentence, the plan fails.
Max and Bigger talk on the day of Bigger’s death. Bigger tries to get Max to see how he’s been enlightened through this experience; Bigger now realizes that whites are human, too, and he wishes he had a chance to live life now with this awareness.
When Max leaves, Bigger tells him to say hello to "Jan" for him and we realize that Bigger has finally accepted that Jan is a friend to him.
In the final scene, Bigger is alone, waiting to be taken to the electric chair.