Heat turns the whole day into a pressure cooker, and Gatsby's parties have already gone dark. Nick notices cars turning into the drive and leaving a minute later; when he checks on Gatsby, a hostile butler says he is not sick, just done playing host. That same brutal Saturday, Nick rides the commuter train through a day so hot the conductor's hand leaves a stain on tickets and every gesture feels like an insult to life itself. He and Gatsby arrive at the Buchanans' for lunch. The room is shadowed and still; Daisy and Jordan lie on the couch like silver idols while Tom argues on the phone about selling a car to Wilson. Jordan whispers that the caller is Tom's girl. Daisy kisses Gatsby in front of everyone, then Pammy, their daughter, is brought in. Gatsby stares at the child as if he had never believed she existed. Daisy tells Pammy she hopes she grows up a beautiful little fool, the same wish she once made for herself.
Tom sees what he needs to see. When Daisy tells Gatsby he always looks so cool, their eyes lock and Tom realizes the affair is real. The afternoon curdles into a plan to escape the heat by driving to town. Tom swaps cars on purpose: he takes Gatsby's yellow Rolls while Gatsby drives Tom's blue coupe with Daisy and Nick. Tom has already been investigating Gatsby's past and drops hints about Oxford, drugstores, and bootlegging before they leave. At Wilson's garage in the ash heaps, Wilson is sick and says he has learned his wife's secret; he talks about God and science while Myrtle watches from the window, her face changing as she recognizes Tom and Jordan in the yellow car she thinks is Tom's. Tom buys Wilson's old Ford and promises to send the yellow car tomorrow. Nick starts to say Daisy's voice is indiscreet, then stops. Gatsby finishes the thought: her voice is full of money. That is the charm Nick had never understood before.
They end up in a Plaza Hotel suite, sweating through mint juleps while an argument nobody can fully reconstruct pushes them into one room. Tom rants about civilization and Mr. Nobody from Nowhere making love to his wife. Gatsby tells Tom that Daisy never loved him and only married him because Gatsby was poor. Tom answers with contempt and investigation: Gatsby is Meyer Wolfshiem's man, a bootlegger who bought drugstores to sell grain alcohol, the man who left Walter Chase in jail. Daisy tries to stop it, then breaks. Pressed to say she never loved Tom, she does, then Tom names their shared memories until she cracks: she loved Tom once, and she loves Gatsby too. Gatsby's face looks, for a moment, as if he had killed a man. The dead dream keeps fighting anyway, reaching for a voice that is already retreating into Tom's orbit. Tom sends Daisy home in Gatsby's car, telling her the flirtation is over. Nick realizes it is his thirtieth birthday as they drive back toward Long Island, the portentous road of a new decade opening in front of him.
On the road home, Wilson has locked Myrtle upstairs after learning about the affair. She breaks free, runs into the street, and the yellow car hits her and does not stop. At the garage, Wilson howls over her body while Tom arrives from New York and tells the policeman the yellow car was not his; he had just come in a different coupe. Only Nick and a bystander hear the lie clearly. Later Gatsby waits in the dark bushes below Daisy's window. He tells Nick that Daisy was driving, that she clutched the wheel when Myrtle ran out, and that he will say he was. Nick peeks through the pantry window and sees Tom and Daisy at the kitchen table, not happy, not unhappy, conspiring over cold chicken and ale while Gatsby keeps vigil outside. The dream does not end with a clean choice. It ends with a death, a lie, and a man still watching the house across the bay.
