Tris doesn't get a chance to warn Tobias in the midst of all the excitement. She wakes in the middle of the night to a peculiar sight; everyone in the dorm is awake and moving robotically, like they're sleepwalking. They start to leave the dorm, moving in unison, so Tris joins them and does the same to blend in. They march into the Pit, where the Dauntless leader Max watches them. They all pick up guns, and she realizes that the injections they received yesterday make them brain-dead soldiers, ready to kill. As they march, she makes a pact to get to the Abnegation sector and save her family, whatever it takes.
The Dauntless leaders are all awake, watching. Tris realizes that she must be awake because she's Divergent, so if her suspicions about Tobias are true, he will be awake as well. She spots him in the train car and at first thinks he's under the simulation like everyone else, but then he discreetly squeezes her hand and she knows the truth. Tobias mouths "run" to her, but she responds back with "my family." They get to the Abnegation sector, and war begins with gunshots. One by one more and more Abnegation drop dead.
They pass by Eric, and he pokes at Tris's injection site, remarking on how insane it is that none of them can process anything that's occurring. He puts a trigger to Tobias's head, planning on "accidentally" shooting him, but Tris pulls out her own gun and points it at Eric's head immediately. While trying to get away, Tris is shot in the shoulder, and they're surrounded by Dauntless soldiers.
They're led into Abnegation headquarters, where they're presented to Jeanine as Divergent rebels. She says she expected this of Tris, but Tobias being Divergent surprised her, since there were no signs. She says she thinks it's because his Divergence is weaker, and he really does belong in Abnegation. She says she wants to test another batch of the simulation on them to see if they can still resist. She also questions why all the Divergent seem to be from Abnegation.
She explains her plans: she wants to overthrow the Abnegation administration, and she promised the Dauntless leaders a place in her new government. She wants the remains of Abnegation to be absorbed into the Dauntless army. She returns again to the problem of Divergence, and says she's created a new serum that will adjust their surroundings to manipulate their will. Tobias will be the first test subject, but Jeanine says Tris is too injured to be of use, so she will be executed in the morning.
Tobias says he would rather die, but of course, Jeanine tells him he doesn't have a choice. He kisses Tris and then lunges across the desk and wraps his hands around Jeanine's throat, which makes the Dauntless guards jump at him. Tris is too small and injured to fight them. Jeanine sticks Tobias with a syringe, and he falls under the simulation. He thinks Tris is an enemy rather than a friend, and tries to strangle her. They're both taken to separate rooms, and when Tris fights back, the guard knocks her unconscious.
She wakes in the corner of a huge tank, still bleeding. There's a tube in the floor, and she realizes with a jolt of panic that she could drown in this tank, one of her worst fears. She screams and pounds on the glass as water begins to trickle in. It rises, and she tries to force herself to remain calm and breathe. As she's beginning to drown, someone comes in and breaks the glass with a bullet, and she realizes it's her mother. Dauntless guards lie dead at the door. Natalie Prior was indeed Dauntless.
Her mom says that her father and Caleb are safe and hiding in a basement, and that she had been keeping an eye on the trains since the attacks started. Tris tries to get over the shock of her mother's hidden past, but then Mrs. Prior reveals that she's Divergent also, and she was only safe because her mother was a Dauntless leader who told her to switch to a safer faction. She explains that the Divergent are terrifying to the leaders of the factions because their minds move in different directions, therefore they can't be controlled, so they must be obliterated.
As they're moving to the basement location, a group of Dauntless soldiers gain on them. Mrs. Prior tells Tris to go to the basement in the alley on the right and knock a certain number of times to get in while she distracts the soldiers. After telling Tris she loves her, Mrs. Prior runs straight at the soldiers and fires at them, getting hit in the abdomen in the process. She falls to the ground and dies; she has sacrificed herself so that Tris can escape.
We've at last hit the climax of the novel, where it reaches its peak with a massive explosion. The tension between the factions and all Erudite's hatred for Abnegation have finally resulted in the beginnings of a true war. From this point on, the novel will move quickly and intensely until it reaches its conclusion with some sort of resolution, though at the start of the attacks, it seems that resolution could end up being many different things.
We've always known that Tris's Divergence makes her special, but in chapter 33, we learn at last exactly how special. Earlier in the novel, Tobias told her that she has the power to manipulate simulations, but in this chapter, it appears she has the power to resist them altogether. The Divergent are so dangerous to the leaders of society because they are completely beyond their control. How, though, can they resist some simulations and not others? Why did Tris fall under the spell of the simulation in the aptitude test, and all the fear simulations, but not the one meant to control the Dauntless as an army? And why can someone be, as Jeanine says, "less" Divergent than someone else? It seems there's a lot more to being Divergent than meets the eye, but because Tris doesn't know these answers, it may be quite some time before we do, as well. Nevertheless, Tris's Divergence and this sequence is a representation of common Young Adult tropes - Tris is special and cannot be controlled, unlike the sleepwalkers around her. Her journey, though heightened and fantastical, echoes that of every teenager who must find their identity among pressures to act a certain way.
Tobias has finally revealed the truth to Tris through a stealthy hand-squeeze: he is Divergent as well, and can resist the simulation. This shows his complete trust in her; this last piece of the puzzle that is Tobias Eaton has finally been solved. Their devotion to each other is tested many times in this chapter: when Eric puts a gun to Tobias's head, Tris could have kept silent, let him die, and been completely safe herself. When Jeanine told Tobias he would be a test subject and Tris would be executed, he could have complied in order to preserve his own life; instead, he lunged at her throat. Both have shown in the face of these trials the selflessness that must be present in real love; they've shown that they truly have Divergent minds, maintaining the virtue of their old faction while still being as brave as their new faction requires. Despite all the horrific challenges, Tris and Tobias have some of their finest moments during this section.
It's interesting how Jeanine uses one of Tris's greatest fears as a method of execution: drowning in a glass tank. She must have had access to Tris's fear landscape in order to know that, no doubt through working with the Dauntless leaders. This shows just how manipulative and cruel Jeanine is; while she could've merely buried a bullet in Tris's head, she instead chooses to torment her with one of her fears, so that when Tris dies, all that consumes her is sheer terror. There's a sort of sadism there that can only be attained by the most evil of antagonists.
Then, of course, there's Tris's mother's sacrifice, the greatest representation of the theme of family this book has to offer. By first risking her life to save Tris, then giving up her own life to allow her to escape, Mrs. Prior has shown that her values are the opposite of those preached by their society: for her, it's blood before faction. Some may argue that what she did was considered suicide, and we already previously established that suicide is not a representation of bravery in the context of this world. However, Mrs. Prior's sacrifice was not out of a desire to die, but a desire to protect her daughter's life; it was the ultimate expression of bravery and love, not cowardice. She cannot be compared to Al, who killed himself simply because he could not handle the pressure of Dauntless initiation and unrequited love. Along with the theme of choices, Mrs. Prior made a drastic decision that changed her life forever by ending it, but also, one that showed who she truly is: a loving, brave mother, not a rigid faction-member, and the embodiment of the best of both Abnegation and Dauntless.