“I shiver. The way he talks about getting out—it’s like he thinks we’re trapped. I never thought about it that way before and now that seems foolish.”

Tris, Tobias, Caleb, Peter, and Marcus manage to escape Erudite headquarters because Tobias remembers the combination to the lock on the gate. For the first time, it dawns on Tris that the gates have meaning. The symbol of the locked gate here echoes the fact that the characters are physically and mentally trapped by their system. Images of entrapment and escape appear throughout the novel.

“I open my eyes, terrified, my hands clutching at the sheets. But I am not running through the streets of the city or the corridors of Dauntless headquarters. I am in a bed in Amity headquarters, and the smell of sawdust is in the air.

I shift, and wince as something digs into my back, I reach behind me, and my fingers wrap around the gun.

For a moment I see Will standing before me, both our guns between us—his hand, I could have shot his hand, why didn’t I, why?—and I almost scream his name.”

This is one of many times that Tris experiences symptoms of Post Traumatic Stress Disorder; her PTSD results from her guilt for shooting Will and having witnessed the violent deaths of her mother and father. The trauma of war and the toll it takes is an underlying theme of the novel. As a member of her new faction, Dauntless, Tris finds that violence has severe consequences for her. She has never been at ease with the kind of violence Dauntless celebrates, and when she chooses to use violence, she is haunted by her decision throughout the novel. In fact, she continues to suffer from nightmares for the rest of the novel.