1984 is set in a possible future in which the world has been ravaged by war and hungry and fearful citizens must pledge allegiance to a paranoid regime that keeps them ignorant through misinformation. Winston Smith, the main character of the novel, lives in London—though England is now called Airstrip One. Airstrip One is part of a large superstate called Oceania, which comprises all of Britain, Iceland, Australia, and New Zealand, as well as the Americas and southern Africa.
In Oceania a force called Big Brother watches and spies on people through telescreens, which are like TVs that transmit both ways. It does double duty, spying on citizens and transmitting pro-Party propaganda, instructions, calisthenics, pro–Big Brother music, and more. The city is plastered with Party slogans such as WAR IS PEACE, FREEDOM IS SLAVERY, and IGNORANCE IS STRENGTH. This is doublethink, a concept that rules Oceania. Doublethink is the ability to hold two opposing beliefs at the same time and accept both of them. But doublethink concepts cancel each other out and, therefore, make no sense.
The Ministry of Truth, where Winston works, is in charge of rewriting history to align with what the Party decides is truth at the moment. The Ministry of Love is in charge of law, order, and torture; the Ministry of Plenty is in charge of economic affairs and the perpetuation of artificial scarcity; and the Ministry of Peace is in charge of perpetual war.
Winston writes in his diary about his hatred for the Party. As he writes—itself a crime punishable by death—he remembers two people he noticed that morning at work. The first is a coworker named O'Brien. O'Brien appears to be an orthodox Party member, but Winston decides that he is really a rebel. The other is a young woman known at first only as "a dark-haired girl."
At work one day, Winston discusses editing the Newspeak dictionary with Syme, a coworker. Syme's job is to eliminate words from Oldspeak (Standard English) and come up with a language with very few words. Newspeak deprives people of the ability to express themselves in any nuanced way or have individual ideas.
Winston visits Mr. Charrington, the unassuming cockney owner of an antique shop. Mr. Charrington shows him an upstairs room that appears to be without a telescreen. Winston imagines renting it as a refuge, and, as he leaves the shop, he sees the dark-haired girl again.
The dark-haired girl, Julia, surreptitiously drops a note into Winston's hand that says, "I love you." Winston and Julia begin to meet away from telescreens and microphones. They meet often in the midst of loud, angry, crowds thick enough that they can touch hands without being noticed. Once they make love in the belfry of a church. Eventually Winston rents the room above the antique shop, and they meet more frequently.
Winston takes notice of an elderly woman whom he sees often doing laundry and singing. He thinks she is happy and free. Like other proles (or working-class people), she is "off the radar" of the Party. Many proles don't even have telescreens in their houses. Winston realizes that the Party will only be overthrown if the proles come to understand their power and rise up.
One day at work, O'Brien invites Winston to his posh apartment. Julia goes along, and they tell O'Brien they want to join the Brotherhood, the group believed to be fighting the Party. O'Brien asks them a series of grisly questions to determine what they are willing to do for the cause. Julia's only condition is that she is unwilling to be separated from Winston. O'Brien accepts them and makes plans to get Winston a copy of the manifesto (nicknamed "the book"), or mission statement, of the counterrevolutionary leader Emmanuel Goldstein.
Later Winston reads aloud to Julia from "the book" in the room above the antique shop. When a voice comes from behind a picture on the wall, they realize there is a telescreen in the room and that they have been discovered. Thought Police come into the room along with Mr. Charrington, who is revealed to be an orthodox Party member.
Winston and Julia have been separated and presumably taken to different prisons. Winston is being held prisoner with other suspected dissidents. One man piteously begs to be taken anywhere but Room 101. Eventually O'Brien enters and reveals that he is also a true member of the Party. A guard takes Winston to a private cell, where he is tortured and admits to things he's never done. O'Brien alternately dials the pain level up and down, but Winston holds onto what he knows to be true and does not betray Julia. Although he eventually agrees to believe whatever O'Brien says, one night he calls out Julia's name, showing his humanity is still intact.
Winston is eventually taken to Room 101, the place where prisoners are forced to face their worst nightmares. O'Brien shows Winston a cage with rats in it and tells him that the hungry rats will eat his face if they're let free. Winston, who has a phobia of rats so severe that it makes him faint, is defeated and calls out, "Do it to Julia!" before losing consciousness.
Winston is released, and, in the next scene, he is at his favorite café. He has gained weight, has a better job at the Ministry, and has enough money to drink all the gin he wants. In fact, he lives for gin, doesn't care about truth or untruth, and accepts doublethink. He sees Julia on the street one day, and they each admit that they betrayed the other. They talk briefly, but they don't seem to connect. In the dust of the table, Winston draws 2 + 2 = 5 and then looks at a poster of Big Brother and asks himself why he ever rebelled against that loving face.