Amar agrees to drive Christina, Tobias and Peter into the city. Each of them inoculates themselves against the memory serum, just in case the reset isn’t successfully stopped. Peter, however, only pretends to inject himself, seeming to volunteer to forget everything. Then, Tobias creates a plan that will hopefully stop a war from breaking out in the city after the memory reset is shut off. While Christina and Amar find Uriah’s and Christina’s family in the city, Tobias will inject the memory reset serum into one of his parents. This will render his parents no longer at odds with each other and will restore peace; he is hesitant, though, as it means losing one of his parents.
In a secret storage room, Tris and her friends meet to discuss how they’ll activate the memory reset in the compound. Caleb volunteers to enter the Weapons Lab and set off the memory serum after the doors are broken through with explosives. He’ll wear a clean suit, but the death serum will get to him eventually. He agrees to sacrifice his life, out of what seems to be both love and guilt for Tris. Tris doesn’t know how to take this news – both hating and loving her brother. In the dormitory, Tris and Tobias have a very romantic moment together before they must take action.
Tobias teaches Caleb how to fire a gun accurately in the target practice room, so that he’ll be able to defend himself on the way to the Weapons Lab. The entire group that will remain in the compound – Tris, Cara, Matthew, and Caleb – inoculates themselves against the memory serum. Tobias goes to visit Uriah one last time, and he sees Matthew. He asks Matthew why he is helping them to fight the Bureau. Matthew tells Tobias about an old girlfriend. She was a GD, so they were forbidden to date, yet they did anyway. She was beaten up by a group of GPs, who were never punished, and she died a year later as a result. “I know it doesn’t seem like it, but I hate them,” Matthew says (428).
Tobias and Tris say good-bye as they part, Tris to stay in the compound and help with the Bureau’s memory reset, Tobias to go into the city and find Uriah’s family. The group entering the city leaves the compound. Christina fakes a bathroom break to slash the tires, so that Tobias can leave the group to go find one of his parents to reset. Peter insists that he come with Tobias. Tobias can’t seem to decide which parent he will go after. Tris and Caleb prepare to breach the Weapons Lab – and she asks him why he’s really giving up his life for this. He tells her that “it’s the only way I can escape the guilt for all the things I’ve done,” which is not what Tris wanted to hear (447). Then, an emergency lockdown is initiated in the compound, and they are forced to spring to action.
In the city, Peter tells Tobias why he wants to have his memory reset. It is because he is tired of being evil – doing bad things, liking it, and then wondering why he is this way. He wants to start over, even if it’s “the coward’s way out” (451). Chaos in the compound ensues. Tris and Caleb are caught by armed guards and told to stop; she forces Caleb to give her the explosives, realizing that she cannot possibly allow him to go into the Weapons Lab. He would certainly die, but she may be able to fight off the death serum. She barely makes it to the Weapons Lab and uses the bombs to break through the doors.
Tobias, at the last moment, decides to go see Evelyn at Erudite headquarters. He tells her about the Bureau’s plan to reset the memory of everyone in the city, and he tells her that he came to force her to drink the memory serum and prevent all-out war. He realizes, though, that he cannot do that to his own mother. He pleads with her that “there’s a hope of reconciliation between us” (465). Tobias gives Evelyn a choice – to continue her war against the Allegiant, thereby losing her son forever, or to let her tyrannical crusade go and get her son back. Evelyn chooses her son. Meanwhile, in the Weapons Lab, Tris combats the death serum. It is only her desire to live that keeps her from joining her parents. The serum doesn’t kill her, somehow, but David finds her, telling her not to move before she has initiated the Bureau’s memory reset.
Peter’s characterization elevates to an unprecedented level during this section. At first, he only acts as if he is inoculating himself against the memory serum when the others inject themselves. He then follows Tobias into the city to find Evelyn, prepared to have his memory reset. Tobias asks Peter why he is so set on this, and Peter reveals to readers that he is not happy with who he is. He doesn’t like to be evil, hurting others and enjoying it. This makes the reader sympathize with Peter, that he can be so disgusted by himself to simply not want to be himself anymore. But, then, Peter is shown to be lazy. He doesn’t want to take the harder route of forcing himself to make better decisions and fighting his nature. His cowardice and disgust with his own nature present Peter in an all-new complexity.
Tobias’s seeming frustration at having to choose which of his parents to reset with the memory serum so as to stop the city from entering a civil war of sorts is hyperbolized in this section. He acts as though he isn’t comfortable injecting either of his parents – as it will mean losing one of them, regardless. Yet, his father was abusive, and his mother abandoned him from a young age. The reader wonders why he would feel uncomfortable about resetting his father’s memory, especially. He doesn’t interact with Marcus, and he probably never would in the future. Isn’t his decision easier than it is presented as it goes through his head? If he wants to negotiate with one of his parents, he should choose Evelyn. If he wants to simply inject one of them with memory serum, he should choose his father, the man who physically abused him for years.
Another internal conflict occurs within Tris. After her brother, Caleb, volunteers to sacrifice his life by entering the Weapons Lab to set off the memory serum in the Bureau, she cannot help but feel uncomfortable. Her brother is agreeing to his own execution. She must recall when she did the same thing, turning herself over to Jeanine Matthews in the past. After that series of events, she realized her will to live. Caleb must have a will to live, if only he can get over his guilt. Can she deny someone else the will to live? Can she deny herself that will? Caleb asks her, also, if she has forgiven him for all of the wrong he committed against her. Eventually, she knows that she cannot let her brother enter the Weapons Lab. She loves him too much, and she knows that his sacrifice is only out of guilt, not out of love.
Somehow, the author works a wave of nostalgia into this section of the story, before the characters enact their plan. Tobias takes Caleb, Christina, and Tris to the practice room in order to work on their shooting. It is reminiscent of the days of Dauntless training. It seems that the characters have come full circle. The amount of strife and change that the characters have had to deal with over the course of the series is incomprehensible, yet they are back where they started – practicing the act of shooting a gun.