The novel's protagonist, Winston Smith, is a citizen of Oceania, one of the world's three superstates (along with Eurasia and Eastasia). It is the year 1984, and Winston lives in Airstrip One, which used to be known as Great Britain. Winston is a member of the Party, which rules Oceania under the principles of Ingsoc (English Socialism). Oceania is an oligarchy, under hierarchical rule. The Party consists of Inner Party members, who are the ruling elite, and regular Party members, who are citizens of Oceania. Outside of the Party are the proles, non-Party members and simple people who live in poverty and are free from Party regulations. The Party's leader is Big Brother, and there are massive images of his kind visage, complete with dark hair and a substantial mustache, displayed throughout London, some accompanied by the words "Big Brother is Watching You." The Party's three slogans are: "War is Peace," "Freedom is Slavery," and "Ignorance is Strength."
Winston lost his parents and little sister during the Revolutionary period that destroyed capitalism and instituted Ingsoc in Oceania. He was placed in a Party orphanage and integrated into the Party system. Now he works in the Records Department of the Ministry of Truth, which handles all Party publications and propaganda, altering previously published Party publications to ensure that the Party's version of the Past is never questioned. Such alterations often remove a person from history, or make previously flawed predictions accurate. The other three ministries are the Ministry of Love, which handles all Party prisoners, the Ministry of Peace, which handles war, and the Ministry of Plenty, which manages the production of Party goods, including Victory cigarettes, Victory gin, and Victory coffee, all of which are of extremely poor quality.
Winston has never quite accepted the principles of Ingsoc and the Party. He believes in an unalterable past, and finds Party politics reprehensible. Winston wishes for privacy, intimacy, freedom and love, but cannot express any of this in the open for fear of death. Such thoughts constitute "throughtcrimes," which are highly punishable offenses resulting in arrest, imprisonment, torture, and often death.
When the book opens, Winston is at home during his lunch break. He has returned to his apartment in the Victory Mansions, a dilapidated Party housing building, to write in a diary, a relic of the past he obtained from an old junk shop. Winston's apartment is meager, and like every other Party member's home, contains a telescreen. The telescreen transmits Party information and propaganda, and also allows the Thought Police to watch and listen to Party members at all times. In Oceania, there is no such thing as privacy. Winston is fortunate to have a small nook in his apartment out of the view of the telescreen, and it is in this nook that he begins to write in his diary, despite his overwhelming fear of being caught. Undoubtedly, Winston will eventually be caught, imprisoned, and tortured by the Thought Police. For now, however, he chooses to forge ahead with his rebellion.
Winston writes of various memories, all related to the Party and his life. Many include violent imagery, which is quite common in the age of Oceania, and reveal anti-Party feelings. Winston clearly does not subscribe to Party doctrine. Winston is briefly interrupted at one point by a knock on his door. At first he panics, thinking he has already been caught, but it is only his neighbor, Mrs. Parsons, who needs help unclogging her sink. Winston obliges, and interacts briefly with Mrs. Parsons' two hellish children who are members of the Spies and Youth League, and clearly powerfully indoctrinated in the ways of the Party. Winston predicts that eventually these children will turn their loyal, simple, innocent parents into the Thought Police. Such tragedies, it seems, are quite common.
Winston returns to his diary, and in one of his reveries reflecting on the past and his memories and dreams, finds himself writing "DOWN WITH BIG BROTHER" in large letters over and over on the page. Eventually, time runs out and Winston must return to work, which he enjoys. Once Winston found a newspaper clipping among his daily assignments that proved the innocence of three men: Jones, Aaronson, and Rutherford. In examining the clipping, he knew it meant the Party was wrong, and that he had real evidence of an accurate version of the past. Rather than risk discovery, however, he destroyed the clipping, placing it in a memory hole that sucked it into the building's internal furnaces.
At the Ministry of Truth Winston is surrounded by loyal Party members, and is always on guard to prevent his true feelings from being perceived by others. At work, Winston sits through the daily Two Minutes Hate, which rails against Oceania's enemy, Eurasia, and the supposed leader of the opposition movement, Emmanuel Goldstein. The propaganda is powerful, and the people around him begin shouting at the screen. Of course, Winston must join in to avoid suspicion.
Finding himself increasingly curious about the past, Winston wanders the streets, among the proles. He believes that if there is hope for a successful rebellion, it lies in the proles. Winston meets an old man in a prole pub and questions him about life before the Revolution. To his frustration, the man focuses on his own personal memories rather than on the generalities and conceptual differences Winston is interested in. Winston returns to the junk shop where he bought his diary and purchases a glass paperweight with a piece of coral inside. The proprietor, a kind old man named Mr. Charrington, shows him a room above the shop and Winston thinks about what it might be like to rent it out and live among old things, free from the constant presence of the telescreen.
At work and on his walk, Winston sees a dark-haired girl who is seemingly a violently loyal Party member and apparently has taken notice of him. He fears she is a member of the Thought Police. One day, at the Ministry of Truth, the girl slips him a note after falling down in the hallway, requiring Winston's assistance. The note says "I love you." Winston is astounded, but extremely excited by the possibility of a love affair. The affair must be secret, as the Party is entirely against any sort of sexual pleasure. In fact, sexual repression is a tenet of Ingsoc. The Party must approve every marriage, and it is unacceptable for a man and a woman to express any physical attraction for one another. All energy must be devoted to the Party. Winston was once in such a marriage. His wife Katharine was a frigid, mindless woman who was extremely loyal to the Party, but thought sex was a vile activity. However, she regularly scheduled times for her and Winston to make love, calling it her "duty to the Party." She had been taught from childhood that she must bear children.
With a great deal of effort to remain undetected, the girl finally tells Winston where and how they can meet. On a Sunday afternoon, he travels into the country, as per Julia's instructions, to meet her in a secluded clearing in a wooded area. Finally, they can speak. Winston learns that her name is Julia, they discuss their beliefs regarding the Party, and they begin their love affair. At one point, Winston notices that the secluded spot she has led them to exactly matches a place he constantly sees in his dreams that he has termed the Golden Country.
Winston and Julia, who has a knack for finding abandoned locales and for obtaining black market goods such as real coffee, bread and sugar, continue to meet in secret. They are limited to interacting only in public places and having only the most minimal conversations, but the two discover a mutual hatred of the Party and eventually fall in love. Winston believes that it is possible to overthrow the Party, while Julia is satisfied simply living a double life. On the surface, she is loyal to the extreme, a member of the Junior Anti-Sex League, a volunteer in many Party activities, and a vocal participant in loyalty-testing events such as the Two Minutes Hate. On the inside, she thinks of it all as a game. She hates the Party and all it stands for, but knows she can do nothing to change it.
Eventually Winston rents the room above Mr. Charrington's flat. Winston and Julia meet often in the room, which is simply furnished, with an old twelve-hour clock (the Party uses twenty-four hour time), and a picture of an old London church, St. Clement's Dane. Mr. Charrington taught him the first lines of an old poem about the church, "Oranges and lemons say the bells of St. Clement's," and Julia knows a few more lines that her grandfather taught her when she was very small. Outside their window, a middle-aged prole woman is constantly hanging her wash and singing simple prole songs, many of which have been created by machines in the Ministry of Truth specifically for the proles.
Another Party member suddenly takes on an important role in Winston's life. Winston has always noticed O'Brien at the Ministry of Truth. He seems to be an intelligent man, and Winston believes in his heart that O'Brien feels the same way he does about the Party. Once, during the Two Minutes Hate, the two men locked eyes and Winston felt sure of O'Brien's thoughts. In a dream, Winston once heard someone tell him, "We will meet in the place where there is no darkness," and he believes the voice to have been O'Brien's. For Winston, O'Brien represents the possibility of an underground movement. Perhaps the Brotherhood, led my Emmanuel Goldstein, is real.
O'Brien approaches Winston at work under the pretense of discussing the Tenth Edition of the Newspeak Dictionary (Newspeak is the official language of Oceania, and its goal is to reduce and simplify vocabulary). O'Brien gives Winston his home address, supposedly so he can come pick up an advance copy of the new book. Winston takes the slip of paper with amazement. He knows that O'Brien has approached him because he is part of the underground movement. His true path towards rebellion has begun.
After some time, Winston and Julia visit O'Brien, an Inner Party member who has a lush apartment, a servant, and the freedom to turn off his telescreen. Winston renounces the Party and discusses his belief in the Brotherhood. O'Brien welcomes Winston and Julia into the Brotherhood and tells them that they must be willing to do anything to work towards its cause. They agree, but say that they will not do anything that would prevent them from seeing each other ever again. O'Brien tells Winston that he will give him a copy of Goldstein's book, and outlines a complicated version of events that will lead toward the exchange. Winston leaves after a final toast with O'Brien, in which Winston finishes O'Brien's statement, saying that they "will meet in the place with no darkness."
During Hate Week, the Party's enemy becomes Eastasia rather than Eurasia, and Winston must spend a great deal of time at work, sometimes even staying overnight, to "correct" all Party publications previously referring to war with Eurasia. The Party is at war with Eastasia, and has always been at war with Eastasia. In the midst of Hate Week, a man brings Winston a brief case, suggests that he dropped it, and leaves. The book is inside. When he has finally completed the Hate Week corrections, Winston escapes to Mr. Charrington's apartment and begins to read. Julia arrives, and he reads aloud to her about the history of Oceania, capitalism versus totalitarianism, and the main goals of the Party. Most of this information Winston already knows, but he finds it helpful to read it in the detailed, clear words of Emmanuel Goldstein.
Winston and Julia eventually fall asleep. The wake hours later, and go to stand at the window. Winston repeats his oft-stated phrase, "We are the dead." Suddenly, a voice coming from the wall echoes him, "You are the dead." There is a telescreen hidden behind the picture of St. Clement's Dane. They are caught. The Thought Police storm the room. Mr. Charrington walks in, and it becomes clear that he is a member of the Thought Police. He has been disguised as a kind old man, but is far younger than Winston imagined, with different hair and eyes. Winston and Julia are arrested, separated, and brought to the Ministry of Love.
While in a holding cell, Winston sees men from the Ministry of Truth come and go. Each has been arrested for thoughtcrime. Parsons arrives, and it turns out that his daughter turned him in, claiming to have heard him say "Down with Big Brother" in his sleep. Winston's prediction, it appears, was sadly accurate. In his holding cell, Winston sees a great deal of violence, and notices guards constantly referring to "Room 101," a phrase that seems to instill great fear in some of the prisoners.
Eventually, O'Brien arrives. It becomes clear that he was never part of the underground movement, but actually works in the Ministry of Love. Winston's entire interaction with O'Brien was a ruse. Winston is removed from the holding cell, and his torture begins. At first the torture is extremely violent, and he is forced to admit to a litany of crimes he did not commit, including murder and espionage. Eventually, the torture becomes less violent and O'Brien takes over. He begins to break Winston's spirit, telling him that his memory is flawed and that he is insane. Winston's discussions with O'Brien dwell on the nature of the past and reality, and reveal much about the Party's approach to those concepts. The Party, O'Brien explains with a lunatic intensity, seeks absolute power, for power's own sake. This is why it will always be successful, is always right, and will ultimately control the entire world. Winston cannot argue; every time he does, he is faced with obstinate logical fallacies, a completely different system of reasoning that runs counter to all reason. Winston believes in a past that never existed, and is hounded by false memories. To be cured, Winston must overcome his own insanity and win the war against his own mind.
Little by little, O'Brien shows Winston, with the use of electric shock machines, beatings and starvation, the way of the Party. He forces Winston to accept that if the Party says so, two plus two equals five. Winston had once written in his diary that freedom meant being able to say that two plus two is four. His final attempt to argue with O'Brien ends in O'Brien showing Winston himself in the mirror. Winston is beyond horrified to see that he has turned into a sickly, disgusting sack of bones, beaten into a new face. Broken to the core, Winston finally submits to his re-education. He is no longer beaten, is fed at regular intervals, is allowed to sleep (though the lights, of course, never go out), and begins to regain his health. Although seemingly making progress in accepting the reality of the Party, Winston is still holding onto the last remaining kernel of himself and his humanity: his love for Julia. This comes out when, in the midst of a dream, Winston cries aloud, "Julia! Julia! Julia, my love! Julia!"
O'Brien's last efforts with Winston are focused on forcing him to betray Julia. He takes Winston to Room 101, containing the worst thing in the world, which is different for everyone. For Winston, "the worst thing in the world" is a rat. Winston is tied to a chair, and O'Brien begins to attach a mask/cage contraption containing huge, hungry, carnivorous rats to his face. Winston feels a desperate, deep, panicked fear. He cannot take it, and finally screams for O'Brien to put someone else in his place - anyone, even Julia. O'Brien has succeeded.
Winston, a damaged, changed, empty shell of a man, is released into the world. In his new life, he sees Julia once, by chance, but they are no longer in love. Each betrayed the other, and prison changed them powerfully. There is no hope for their relationship. Winston obtains a somewhat trivial, meaningless job that pays surprisingly well. He spends his time at the Chestnut Tree Cafe drinking Victory Gin and playing chess. His life is buried in gin. In the final pages of the novel, we find Winston in his regular seat at the cafe, drinking gin, playing chess, and waiting for a report from the front in Central Africa, where Eurasia (Oceania was always at war with Eurasia) has invaded. He is excited about the report, because with this invasion, Eurasia might actually be able to break Oceania's line of defense and put the entire nation at risk for takeover. A Eurasian success in Central Africa might mean the end of the Party. Before the report comes, Winston suddenly recalls a very happy day in his childhood spent playing board games with his mother and little sister. He pushes it out of his mind, realizing it is a false memory and resolving to allow fewer of those to creep up on him. Eventually, the report reveals that Oceania has succeeded in repelling the Eurasian advance. There is jubilation on the telescreen and in the streets. Staring into the eyes of a poster of Big Brother, Winston realizes that he knew this news would come. With tears dripping down his face, Winston realizes he has finally completed the rehabilitation he started in the Ministry of Love. He loves Big Brother.