Plot synopsis
(From Wikipedia)
In a dystopian Chicago, 16-year-old Beatrice "Tris" Prior has always felt different from the rest of her family. She was raised in the Abnegation faction, where she was trained to be selfless. There are five different factions in the city: Candor (the honest), Erudite (the intelligent), Amity (the peaceful), Dauntless (the brave), and Abnegation (the selfless). Despite her upbringing, being selfless has never come naturally to Beatrice. She is conflicted by her feelings of loneliness and extraneousness.
Beatrice takes an aptitude test and learns that she is Divergent. This means she is not suited for just one faction. In her case, she is suited for three: Dauntless, Abnegation, and Erudite. She is told never to share this information with anyone.
During the Choosing Ceremony, in which all 16-year-olds decide which faction they will join, Beatrice and her brother, Caleb, select rival factions. Beatrice immediately begins initiation into the Dauntless faction, which begins with a challenge of jumping off of a moving train to a roof seven stories high. She also must jump into a pit.
Soon after her arrival in Dauntless, Beatrice makes three new friends. The first is Christina, a loquacious Candor girl with a penchant for brutal honesty. She also befriends Will, a studious Erudite boy, and Al, an emotionally volatile Candor boy. Among Beatrice's enemies are Peter, a violent, menacing, and viciously competitive Candor boy, and his two sidekicks, Molly and Drew. Tris also develops a crush on one of the Dauntless instructors, named Four.
A large component of the Dauntless initiation process is physical fighting, and while Beatrice is beaten into unconsciousness by Peter during one fight, she begins to become a stronger and better fighter as she triumphs over fellow initiate Molly in a fight. Her friend Al, despite being large and physically brutal, does not believe all of the fighting and violence is necessary for the initiates to learn. He reveals that he only chose Dauntless to make his father proud, and wishes it would maintain its key values of altruistic bravery, rather than attempting to eradicate cowardice.
Toward the end of stage one, Tris physically becomes stronger and fitter and begins to win fights. On the last day of stage one, she is publicly humiliated and sexually harassed by Peter, Molly, and Drew. In her anger, she promptly beats Molly unconscious without guilt. Tris is later quite surprised to find, during rankings, that she ranked near the bottom but will not be cut and become factionless.
During the margin between stage one and stage two, Tris is awoken by a stirring on the other side of the room. She discovers that it is fellow initiate and Erudite transfer Edward, who was stabbed in the eye with a butter knife by a jealous Peter. He and his girlfriend Myra quit and became factionless, bumping Tris' ranking up to fifth and Peter's up to first.
As stage two unfolds, Tris further develops her relationship with Four, and they grow closer but more seclusive. Stage two centers largely on emotional challenges and every day the initiates are put under a monitored simulation that places them in hypothetical but realistic and engaging scenarios where they confront their greatest fears, one after another, until are are met and conquered or failed. The simulations turn out to have very drastic emotional effects on the initiates, but Tris' Divergence appears to psychologically set her apart from her fellow initiates. While initiation is stressful, the simulations are much less challenging for her. Tris ranks highly at the end of stage two, prompting jealousy from Peter, Molly, and Drew. In between stages two and three, Tris is attacked by Peter, Drew, and Al, and she is hung over a chasm. Four, however, comes to her rescue and takes her to his apartment in Dauntless.
In the days following, Tris' relationship with Four proves to be advantageous. She learns that stage three focuses on a more advanced version of the simulations, and the initiates will be ranked according to how many fears show up in their fear landscapes. She and Four go through his fear landscape, and there she learns that Four was originally a transfer from Abnegation named Tobias, who transferred to Dauntless due to a history of physical abuse from his father. Tris also learns that Tobias' nickname 'Four' comes from only having 4 fears in the fear landscape, which is a record in Dauntless that is yet to be beaten. Their relationship steadily grows stronger, though publicly Tobias begins to avoid her to prevent questioning and potential claims of unfairness from the other initiates.
Tris ranks highest at the end of stage three. After her fear landscape, she is injected with a newer version of the serum, one which causes the non-Divergent to sleepwalk and be better suited for murdering others. The Erudite, who long have held a grudge against the Abnegation, stage a large slaughter using the Dauntless as brain-dead, homicidal soldiers. Tris and Tobias, who are both Divergent, are not affected by the simulation and instead work toward saving the Abnegation, including Tris' parents. They attempt to escape, but as a result Tris is shot in the shoulder and they are captured. The leader of the Erudite then injects Tobias with a new and improved serum that can affect the Divergent. Tobias is then taken away to the control room and Tris is taken to what will be her execution. Tris escapes execution threats unscathed with her mother, though without Tobias.
Tris' mother is fatally shot by Dauntless soldiers to provide Tris the distraction she needs to meet up with a group of Abnegation members including Caleb, her father, and Tobias' father. Eventually the four of them set out to locate the control room and free the Dauntless from their mind control. They find a fully awake Peter, who was removed from the simulation by Dauntless leaders. He reveals the location of the control room when put under severe duress, but begs Tris to take him with her.
Tris locates the building where the control room is, but her father is shot on the way there, also sacrificing his life to save hers. Tris finds Tobias, still under Erudite control, in the control room. She briefly fights to break him free from the simulation. She succeeds, despite Tobias coming dangerously close to shooting her. Once freed from his simulation, he works desperately to free the rest of the Dauntless. Once Tobias succeeds, he, Tris, Marcus, Peter and Caleb board a train to the Amity sector of the city, where they hope to find peace in the next novel in the trilogy, Insurgent.