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