Insurgent

The escapees jump onto a train heading into the city. It contains armed factionless, including Edward, the Dauntless initiate who left after Peter stabbed him in the eye. When the factionless order them to jump off the train or be killed, Tobias tells them that his name is Tobias Eaton. The factionless immediately stand down. Edward escorts them to a factionless safe-house, where they are greeted by Evelyn, the leader of the factionless and Tobias’s mother. 

Evelyn asks Tobias to join her group of factionless, who want to destroy the faction system. Tobias doesn’t agree with this goal, saying he’s chosen Dauntless. Later, Tobias tells Tris that he’s known for about a year that his mother is alive; he’s still angry with her because she left him behind with Marcus instead of taking him with her when she left. However, he tells Tris that an alliance with the factionless may be their best hope.

When Tris and her friends have dinner with the factionless, they all share information. The remaining Abnegation have joined the factionless, while Dauntless has been split in half, with the traitors joining the Erudite and the rest staying with Candor. 

Tris overhears Tobias and Evelyn discussing safe houses and the population counts that Evelyn is mapping. The population she is counting is the Divergent; she wants to know, when it comes to a fight with the Erudite, how many of the factionless are immune to the simulations. Evelyn knows that eventually the Erudite will want more soldiers, and they will come for the factionless, where there are a very high number of Divergent people. Evelyn plans to overthrow Erudite and eradicate the whole faction system. She wants to set up a government without factions.

Though Tobias does not agree with Evelyn’s plans, she tells him that he should make himself important as a Dauntless leader. The door is always open to him to join forces with her. She also tells Tobias that Marcus always suspected that Tobias was Divergent; she left him with Marcus in the hope that Marcus could protect him better than she could.

Evelyn tells Tris that her father was a childhood friend of Jeanine Matthews—the hated Erudite leader. Tris had no idea her father was born in Erudite, though she knew that he hated Erudite with a great passion. Evelyn goes on to threaten Tris, saying that she is only a temporary fixture in Tobias’s life. Caleb and Susan return to Abnegation’s village. Tobias and Tris go to Candor headquarters to visit what remains of the Dauntless faction there. 

Tris and Tobias are arrested by Dauntless guards in the lobby of the Merchandise Mart, which acts as Candor’s headquarters.

Jack Kang, Candor’s leader, tells Tobias that he is being arrested for crimes against humanity, and Tris is being arrested as his accomplice. They will be tried and questioned while under the effects of truth serum. Christina comes to see her before her “trial” to show her support and to tell her that Will is dead. Tris doesn’t tell Christina the truth, though she admits that she knows that Will is dead. Uriah, Lynn, and Marlene, other Dauntless friends, are also safe in Candor.

Tobias is injected first.

Four/Tobias admits that his real name is Tobias Eaton and that his parents are Evelyn and Marcus Eaton. It is not common knowledge that Four is Marcus Eaton’s son. Tobias also admits that he joined Dauntless to get away from his abusive father, who used to beat him. He admits that his loyalty lies with any faction that opposes the attack on Abnegation. 

Everyone in Candor has seen video footage of the simulation and the battle, including the control room at Dauntless headquarters. Tobias explains that he is Divergent, so the simulation didn’t work on him until he was captured and taken to Jeanine who injected him with a simulation serum targeted for the Divergent. It made him think that he was shutting down the simulation, when he was actually maintaining it. Furthermore, he explains that he saw his friends as enemies and his enemies as friends. When Tris approached him, he saw her as an enemy. Somehow, when she refused to fight him, he recognized her and they were able to shut the simulation down.

When questioned about his regrets, he admits that he should have chosen Abnegation as his faction. He had intended to leave Dauntless before he met Tris, after which he decided to stay. He confesses that choosing Dauntless to avoid his father was cowardly, making him unworthy of being Dauntless.

Tris injects herself with the truth serum. She tells the crowd that her mother helped free her from Jeanine and was killed as a result. Then, she formed a plan with her father and brother to destroy the simulation. They infiltrated the Dauntless compound, and her father died distracting the Dauntless soldiers. When asked what she regrets, she admits that she killed Will when he attacked her under the influence of the simulation.

Christina, Tris’s best friend and Will’s girlfriend, turns away from her as they leave the questioning. Tobias, who did not know about Will, says that they can talk tomorrow. They find cots next to one another. When Tobias falls asleep, Tris returns to the interrogation room. She contemplates suicide, but she stops herself because she knows that she must honor her parents sacrifice. She has to find a way to live with what she has done and move on.

The next morning, Tobias takes Tris aside for a private talk. They argue when Tobias says that he wishes that Tris trusted him enough to tell him the truth about killing Will. Tris realizes that she didn’t trust that Tobias would still love her if he knew the truth about her. She does not tell him this, however; instead, she accuses him of not trusting her with the truth either, such as the fact that his mother is alive or that he wants to join the factionless. In the end, she simply apologizes to him because she never wanted him to know about Will. He isn’t happy and walks away from her.

Lynn takes Tris to bunk with the rest of the Dauntless. They want to join together and try to act like a faction again. Marlene is in a nearby bunk. A group of them decide to do surveillance on the Erudite building that night. Tris goes along but Tobias doesn’t; he doesn’t like heights. As they are gathering in the lobby, they are attacked by Dauntless traitors.

Though Tris has been shot with something, it isn’t a bullet. All of the other Dauntless appear to be lying unconscious as the traitor Dauntless enter through the broken glass windows. Eric, a Dauntless traitor and ex-leader, is in charge of the attack. Tris pretends to be unconscious until she can figure out what is going on. Some of the traitors are injured or killed by the Dauntless who were able to fight back before falling unconscious. Tris steals a jacket with a blue arm-band—the sign of those Dauntless working with the Erudite—from a fallen traitor. She finds Uriah—also a Divergent—and they split up.

Tris searches for other Divergents to save them from Eric and the traitor Dauntless. She saves one little girl before Eric catches her. She is captured and rounded up to be taken to Jeanine, as is Uriah.