"Divergent" follows Beatrice Prior, a 16-year-old girl who lives in a dystopian Chicago. There are five factions of society. On a set Choosing Day each year, every 16-year-old is required to choose a faction for the rest of their lives.
Each faction is devoted to a virtue. The Candor faction focuses on honesty, Abnegation on selflessness, Dauntless on bravery, Amity on peacefulness and Erudite on intelligence. Every 16-year-old takes an aptitude test before choosing a faction. The test determines the faction that suits them best. They can then either join that faction on Choosing Day or stay with their family's faction.
There is an initiation required with each faction. If a person doesn't complete it, he is factionless and must live on the streets.
Beatrice is in the Abnegation faction, but her test results indicate she could be in Abnegation, Erudite or Dauntless. Since her results can't specify one faction, Beatrice is a "Divergent." Beatrice chooses to join the Dauntless faction and renames herself Tris. However, that faction only allows the top 10 initiates to join the faction, while everyone else becomes factionless.
The novel follows Tris during her initiation as well as a romance with the Dauntless instructor, Four, and an attack on one faction by another. It is the first novel in the "Divergent" trilogy.