Prior to the start of the novel, nineteen-year-old Billy Lynn, a soldier in the United States Army, was involved in a firefight on the banks of the Al-Ansakar Canal in Iraq. During the fight, Billy attempted to save his mentor, Shroom, but Shroom died at the hands of Iraqi insurgents anyway. Because the firefight was filmed by an embedded news team, Billy's platoon was renamed Bravo squad, heralded as heroes, and President Bush asked them to return home for a two-week Victory Tour, culminating at the Dallas Cowboys Thanksgiving Day game.
On Thanksgiving Day, Billy arrives in a limo to the Texas Stadium and thinks that it looks very different from the stadium he's seen on television. A group of college girls drives up alongside the limo and yells for the Bravos to put their windows down. When the soldiers do so, the girls' faces fall—they're uninterested in soldiers. A movie producer, Albert, rides with Bravo. He's trying to secure a movie deal to make a film about the firefight, and he announces that the actress Hilary Swank is interested in playing both Billy and his sergeant, Sergeant Dime.
When the Bravos arrive at the stadium two hours before kickoff, none of the staff seem to know what to do with them. Sykes and Lodis wonder what their seats in the seventh row might cost, and Dime discusses the movie deal with Billy and Albert. Billy's thoughts wander to how he ended up in the military in the first place: when his sister, Kathryn, suffered a horrific car crash, her fiancé, pussy boy, broke off their engagement. In retaliation, Billy destroyed pussy boy's car and joined the Army to escape the felony charges. As Billy's mind wanders, he hopes that the Bravos' handler, Josh, will bring him Advil for his headache. Finally, Billy decides to go find beer with Mango. When the two return, Dime is infuriated that they drank, but he sends them off to go find Major Mac, who has accompanied Bravo for unknown reasons. The hunt for him is futile, so Billy and Mango buy more beer and wander into a shop on the concourse selling overpriced items emblazoned with the Cowboys logo. They find the shop absurd.
When they get back to their seats Billy watches a punter warm up on the field and thinks that Shroom's ghost lives at the top of the football's arc. Suddenly, the Jumbotron shows the Bravos in their seats, and grateful citizens mob Bravo and thank them for their service. Billy is stoic and polite but feels as though the people all need something from him. Finally, Josh announces that it's time for lunch and leads the Bravos up to the concourse. More people rush to Bravo, and many tell Billy that the Fox News footage looks just like a movie.
At lunch, Billy feels almost sick at the sight of the massive buffet. He listens to Albert talk about dodging the draft for Vietnam, and Billy loses himself thinking about how Dime and Shroom ran the platoon in Iraq. Albert's conversations about the movie aren't going well, and Dime is especially angry when Albert shares that Universal Studios wants to set their story during World War II. Billy finally escapes to the restroom but is intercepted by Mango and a waiter, Hector. They all go outside to smoke marijuana, and Hector is shocked to hear that the Bravos have to return to Iraq. When he mentions that he's thinking of joining the Army to get health insurance for his young daughter, Billy, Mango, and Hector wonder what else they can do.
The novel steps back in time to Billy's visit home the day before. Billy's father, Ray, had once been a radio DJ, but after he suffered a double stroke, all of Ray's transgressions came out: his apartments in Dallas had been cover for his secret relationships, and he even has a secret teenage daughter. While Ray had once been loud, mean, and proudly conservative, the strokes left him in a motorized wheelchair and mostly unable to talk—a relief to the entire family. Billy's mother, Denise, tries her hardest throughout Billy's visit to make things perfect, but Ray consistently ruins her attempts by smoking constantly and watching Fox News at full volume. In the morning, Billy takes his nephew, Brian, outside to play, and Billy painfully realizes that children like Brian die in the war. Kathryn and Billy's other sister, Patty, join him outside. When Denise's boss, Mr. Whaley, stops by, he praises Billy's heroism and promises to pray for him, though Kathryn insists that Billy could still die. Billy spends the rest of the afternoon napping in the yard and talking with Kathryn. When he leaves in the morning, Ray watches Billy leave but doesn't say goodbye, and Kathryn shares that she's been in contact with an organization that helps soldiers legally desert.
Back in the present, Billy meets Norm Oglesby, the owner of the Dallas Cowboys, in a meet and greet populated by rich Texans. As Billy listens to the conversations around him, he realizes he envies the rich, as the war and death are simple talking points for them. An executive, Mr. Jones, introduces himself to Billy. Billy is strangely angry to see that Mr. Jones is carrying a gun, but he manages to engage Mr. Jones in a conversation about business. As the meet and greet draws to a close, other executives ask Bravo to sign Time magazines, and then Josh takes them to their press conference. When Bravo enters the room where the conference will take place, the cheerleaders go wild. Norm gives a long-winded speech about the Bravos, and Billy makes eye contact with a strawberry blond cheerleader. Later, as two reporters ask Billy about ghostwriting a book about his experience at war, the cheerleader finds him. Her name is Faison, and she tells Billy that being a cheerleader mostly consists of doing service work. She tells Billy that she's a Christian, and as she rattles on about her relationship with Jesus, Billy leads her behind a curtain. They kiss, and Billy picks her up. She orgasms and declares that she knows that what they're doing isn't wrong. As the conference comes to a close, she tells Billy to find her later.
Billy doesn't realize where he is for a full half hour. He finds himself on the football field apparently waiting to film a commercial. Josh arrives with footballs for Bravo to hold, and Billy begins a loose version of tackle football with the other soldiers. After a few minutes two men make the Bravos stop, and a film crew calls them over to film the advertisement. Dime is supposed to wish America a happy Thanksgiving, but he veers off script and also addresses soldiers in the field. Between takes, he and Norm discuss the Bravos' movie, and it takes five takes to get the advertisement right. When it's finished, Norm leads Bravo to the locker room to get autographs from the players. Billy is in awe of the size of the players and doesn't want to pester them, but he feels strange ignoring them. When he gets to Octavian Spurgeon, Octavian asks Billy about the weapons he uses in Iraq. Disturbed, Billy finds Dime, and Ennis, the equipment manager, offers Billy and Dime a tour of the equipment room. Billy feels nauseous seeing the amount of stuff the Cowboys have. Ennis refuses to give Billy Advil for his headache and returns Billy and Dime to the locker room. Octavian calls Billy over and asks if the players could come to Iraq to help out and shoot "Muslim freaks." Billy tells Octavian to join the Army, and Octavian scoffs. Later, Billy gives his football away to a twitchy boy.
Norm invites Bravo to watch the kickoff from his private box. More rich people thank Bravo for their service, and an old man named March Hawey approaches Billy. Hawey knew Bush as a boy and interrogates Billy about the success of the war. Billy lets his mind wander as Hawey talks, and Billy thinks that there's an disconnect between these people's understanding of the war and the reality of it. As the national anthem begins, Billy watches Faison in the line of cheerleaders. When the anthem is over, Billy escapes to the front of the box to watch the game with other Bravos. Hawey finds Billy again and discusses the merits of capitalism. Norm asks Bravo to leave after the first quarter.
Once they're back in their seats, Billy decides to take Mango to go meet Faison. They find her, and Billy feels as though he's never been happier. He receives a call from A-bort instructing him to return, with a cryptic and terrifying message as to what halftime will entail: marching on the field with Destiny's Child. Lodis, who got very drunk before halftime, struggles to follow Billy as the marching bands start up. Fireworks that look like bombs go off, and strobe lights flash. Billy feels as though the ground is tilting as he tries to follow his instructions. The Bravos find themselves backstage, where a woman tells them that next, they'll go out onstage with Destiny's Child. They briefly see Beyoncé as she comes backstage to change, and then they take the stage with her. Billy notices Sykes weeping and looks at the sky.
After the show, nobody comes for Bravos. They're all shaken, and Sykes is still crying. The roadies nastily yell at them to leave and all of a sudden, a brawl breaks out. Cops send Bravo across the field where they're met by Faison. She and Billy exchange phone numbers, and Josh finally appears to take Bravo back to their seats. Billy calls home and speaks to Kathryn, who insists he needs to speak with the organization that will help him get out of returning to Iraq. She screams when he says he wants to go back.
As Bravo settles in to watch the rest of the game, Sykes began singing—Dime gave him Valium to calm him down. Billy receives a phone call from an unknown number. He listens to the voicemail and tries to decide what to do about Kathryn's offer as the boojee lady sitting in front of Bravo notices that Lodis is asleep and kindly covers him with her snuggie.
Dime informs Billy that they're going to meet with Norm. Albert meets them in the hallway outside Norm's office and tells them the news: Norm wants to fund the film, but he only wants to pay the Bravos $5,500 each for their story instead of the $100,000 that Albert promised. Dime refuses the deal, but Norm attempts to force Dime's acceptance by making him speak to the powerful General Ruthven. Dime speaks to the General but leaves the office without accepting Norm's deal. He explains to Billy that General Ruthven hates the Cowboys. With two minutes to go in the game, Dime declares that it's time to leave. Out by the limo, Billy notices the crowd rippling and suddenly, the roadies attack Bravo with pipes and crowbars. Mr. Jones fumbles his gun, but Major Mac shoots it straight into the air. Right after, Billy runs out of the limo to say goodbye to Faison. He knows that their relationship is doomed when she's confused as to why he wants to run away, but they kiss passionately anyway. As citizens mob Billy one final time, Billy realizes that their reality controls the trajectory of the war, and his firsthand knowledge means nothing.