A youth named Equality 7-2521, who has found a hidden tunnel and hides in it to write, knows his solitude violates all the laws of his society. Even though he does not feel guilt for his actions, he begs the forgiveness of the ruling Council. As he spends more time alone, he realizes that solitude suits him, and he begins to crave more and more time by himself. From his tunnel, Equality 7-2521 records episodes from his childhood. As a child, Equality 7-2521 wanted more than anything to be a scholar. He believed he was cursed with a terrific curiosity, which made him prefer some things to others and to prefer some people to others. He often fought with the boys at the Home of Students, and he was reprimanded by his teachers for being too smart and too tall. He tried to conform to the standard the others set, but no matter how hard he tried, he was smarter and quicker than they were. When the Council of Vocations assigned him to be a street sweeper instead of a scholar, he was pleased because it meant he could atone for the sins he had committed.
When he was ten, Equality 7-2521 saw the public execution of the Transgressor of the Unspeakable Word, who had discovered the word “I” and was burned to death in the town square as punishment for using the word. While he was burning, the Transgressor showed no pain but locked eyes with Equality 7-2521. Equality 7-2521 comes to believe that that moment anointed him as a disciple of the same crusade as the Transgressor.
Equality 7-2521 begins to conduct experiments and shortly discovers electricity. After many weeks of work, he successfully builds a lightbulb from the materials he finds in his tunnel. He decides that he must share his invention with the world and resolves to present it to the World Council of Scholars when it convenes that year in his city.
In the meantime, Equality 7-2521 has met the Golden One, a beautiful peasant girl who is proud and haughty. He knows it is wrong to do so, but he speaks to her when he gets the chance, and they immediately fall in love. One day, she offers him some water from her hands, and he drinks it, not understanding why this act makes him think of the Palace of Mating, where he and all other mature citizens are sent once a year to have sex.
Before he can show the lightbulb to the World Council, Equality 7-2521 accidentally returns late to the Home of the Street Sweepers, where he lives. When he refuses to tell his Home Council where he has been, he is thrown into the Palace of Corrective Detention. There he is tortured, but he still refuses to tell where he has been, because he wants to keep the lightbulb a secret until he gets to show it to the World Council. He remains incarcerated until the World Council convenes, when he breaks out of the Palace of Corrective Detention and goes to the World Council, expecting to be exonerated and reconciled with his brothers.
When Equality 7-2521 arrives and tells the World Council his story, however, the World Council rejects him out of fear and anger. It threatens to kill him and to get rid of his lightbulb. He cannot abide having his lightbulb destroyed, so he grabs his invention and flees the city. He runs to the Uncharted Forest where he discovers that he is free at last to do as he pleases.
A few days later, the Golden One appears. She has followed Equality 7-2521 into the woods. They vow to live together in peace and solitude. After they have been hiking for several days in the mountains, they find an abandoned house from the Unmentionable Times. The Golden One revels in the finery she finds in the house, and Equality 7-2521 consumes the library. He discovers the meaning of the word “I,” and he vows to protect his home and from there launch a new race of men who will believe in individualism and the never-ending supremacy of the ego.