The novel opens with a letter someone named Luke writes to T from his cell on death row. He talks about Sister, a nun who comes to visit him and insists he work out his emotions. The story then becomes a narrative and introduces the reader to Toby and Luke, two high school seniors who have been friends for as long as either of them can remember, their poverty bonding them together closer than most brothers.
Luke has been the North Carolina state wrestling champion for three years. He has also been Toby’s defender for most of his life, as Toby is small and has a habit of saying the wrong thing to the wrong people. Toby’s father, a petty criminal and abusive alcoholic, regularly beats Toby.
Toby often spends nights over at Luke’s apartment with Luke and Luke’s younger twin brothers, Jack-Jack and Petey. Luke’s mother works the night shift so Luke spends his evenings watching the 5-year-olds and keeping them out of trouble.
Luke writes again to T, telling how Sister brought him a journal and pen to write down his feelings. He tells T the only way to survive inside is to wear a mask. Sister encourages him to keep writing to Toby, even if he never shows her the letters. Hearing Toby’s name for the first time in a year shocks Luke. He wants to punch the wall until he cannot feel anything.
In the story, Toby falls in love with a new student named Annie. She shows no interest, but Toby thinks they have a connection. She follows him into the cafeteria and threatens to beat him up unless he admits to everyone that she is not his girlfriend. Even after this humiliation, Toby remains hopeful that he can win her over.
Luke works hard to lose weight and practice for his upcoming wrestling competition. Even though he already has a scholarship to college, Luke wants to beat the second-best wrestler in the state. His coach, Coach O, helps Luke whenever he can. He has paid for new wrestling shoes and even paid the electric bill for Luke’s family.
When another wrestler, Tyler, gets in a fight with Toby after practice, Luke barrels in to protect his friend. Coach O stops him from beating Tyler. Later, Toby uses thoughts of Annie to block out Tyler’s taunts. Toby fears the rage he feels will cause him to become as violent as his own father.
Toby’s father, Jimmy, shows up after school. Both Toby and Luke try to keep him from taking Toby home, but Jimmy insists. Toby is shocked when his father gives him the keys to a truck. Meanwhile, Luke finds his mother at home and drunk with Ricky, her new boyfriend. She takes the man to her bedroom while Luke settles his brothers to sleep in the living room and then goes for his nightly run. Luke is surprised to meet Annie in the parking lot, and even more surprised to learn that she has moved into his apartment complex.
In another letter, Luke describes how his time in solitary peeled away pieces of his humanity. Sister and an inmate named Eddie try and talk to him when he gets out, but Luke resists their help. Eddie finally tells Luke that he has a choice to live his life as best he can inside or walk through it like a dead man. Luke writes that he never had a choice. Every moment of his life had been filled with anxiety and risk. In another letter, Luke describes the pain of losing Eddie when his friend is executed.
After Luke’s morning wrestling practice, Toby shows Luke money he found in the truck. Luke worries that Jimmy will beat Toby if they spend it, but Toby offers to take Luke and his brothers out for ice cream later. On his run home from school, Annie stops Luke and offers him a ride. It is obvious she likes him.
Toby is upset when he sees them together. After a tense conversation, Toby tells Luke he is taking him and the boys out to dinner. Toby shoots verbal barbs at his friend, and Luke knows he should have told him about his conversations with Annie. Even though their relationship is strained, Luke offers to let Toby spend the night at his apartment, to keep him away from Jimmy.
Jimmy drags Toby from Luke’s home and insists he drive to The Deuce, a local bar. Jimmy is already drunk, and Toby knows the bar is closed, so he takes his father home instead. Jimmy is furious and beats Toby with his belt buckle, knocking him unconscious. The following morning, Luke worries when he does not see Toby at school. Annie offers to help him find Toby.
They find him curled up near the wreck of an airplane the boys discovered years ago. When they were little, they had hoped to repair it and learn to fly so they could leave their sad homes behind. Now, the plane is their safe zone. Annie lets Toby stay at her apartment while he heals from his wounds. She lives with her stepfather, a trucker who is away on a job. Toby is humiliated to know that Annie has seen him like this. He stumbles home, only to find Jimmy still waiting for a ride to The Deuce. Although he knows it means nothing but trouble, Toby drives him there.
Jimmy is well known at The Deuce, and Val, the bartender, gives Toby a drink to take the edge off his bruises. As he gets drunk, Toby finds himself drawn to Lily, his father’s friend. She takes Toby to her house when he is too intoxicated to drive.
He skips school the following day to spend it with Lily. They picnic in the mountains and then Toby brings her to the plane. It is there that Luke finds him after having spent the past two days worrying. Luke is upset to find Toby drinking and hanging out with an older woman, but the fact that Toby was in The Deuce is even worse. Luke knows that spending time with Jimmy in the bar will only lead to Toby getting sucked into a life of booze and crime. Toby promises he won’t go back there, but neither will he go to Luke’s apartment. He wants to stay with Lily.
Besides the stress of Toby’s problems, Luke is dealing with his own at home. He hates Ricky, his mother’s boyfriend. The two come to physical blows when Luke tries to stop his mother leaving the house with Ricky. But his mother and Ricky take off together.
When Lily shows up the following day and takes Toby out of school, something in Luke breaks. He has enough problems without trying to keep Toby from getting in trouble. Each boy experiences “love” and sex for the first time. But while Annie and Luke want a relationship together, Lily realizes Toby is too young for her. She doesn’t want him to get involved with the job she and Jimmy are planning, in which they will sell a truckload of stolen cigarettes.
Over the weekend, Toby and Luke mend their fraying relationship. Luke’s mother finally returns home Monday morning and announces she and Ricky got married. She wants the boys to skip school to celebrate, but Luke has his final wrestling match that day. Desperate to hear from Lily, Toby goes to her house.
Despite her wanting to break up with him, they have sex, and Toby drives her to The Deuce, rather than attending Luke’s wrestling match. Luke finds himself distracted by Annie’s presence and his worry over Toby’s absence. After three tough rounds, he loses a match for the first time.
Luke goes for a run to clear his head and sees Toby’s truck outside of The Deuce. He confronts Toby inside and is soon in a brawl with Jimmy and his friend Bo. Luke punches Bo several times until Jimmy cracks a beer bottle over his head to stop him. As the cops are called, Luke tries to make Toby leave, but he will not go without Lily.
Luke runs to Coach O’s house for help, but leaves when Coach advises him to go to the police and confess what happened. Instead, Luke runs home to say goodbye to his brothers and Annie, as he wants to leave town for a few days. He arranges to meet with her at the plane wreck later that night.
Bo is too injured to drive the truck of cigarettes to the sale point, so Jimmy forces Toby to help. Toby winds up overcorrecting the steering wheel and rolling the truck off the highway. Knowing his father will be furious, Toby runs to the plane to hide, but Jimmy finds him there, after learning about it from Lily.
Toby tries to fight back, but his father beats him with a tire iron. Luke arrives to find the plane torn to pieces and the battered corpse of his only friend. Beside himself with grief, Luke runs to Toby’s trailer home and finds Jimmy’s revolver. He takes it to The Deuce and shoots Jimmy. When Bo and Val try to stop him, Luke cracks them in the head with the gun, killing them both.
The story ends with another letter from Luke to Toby. He wishes they had had more time together. Although his letters until now have been hopeless, Eddie’s friendship and Sister’s help seem to have given him a small sense that maybe his life could be different.