It takes about half an hour before the train stops in what looks like an unused station. When I disembark and look at the platform, I see that I'm not alone. I am, however, the only person from Abnegation. Some of the passengers must be visiting people other than new initiates, because there are more people here than transfers in Caleb's class. The Erudite look at me with interest, then mild revulsion. I stare them down. They have no idea who I am or who my father is. I don't owe them deference, not here.

I follow the small crowd to the station exit, where a young Dauntless woman with spiky brown hair and a chain linking a ring in her ear to one in her nose greets us.

"Come with me," she says.

No one in the group says anything as we follow her. The front entrance to Dauntless doesn't look like much, just double doors with their flame symbol painted on them, but when I look up I see a building stretching ten stories into the sky. Every pane of glass looks to be intact, so I know it can't be abandoned. Is Caleb in there? Is that where's he's learning to be a soldier?

The Dauntless woman herds me in last. The doors shut and I'm struck by how cool it is in here, almost cold. It's a relief from the outside heat. It's as dark in here as it is cool, too, and I hear a rush of water in the background. As my eyes adjust to the darkness, I take in the size of Dauntless. It seems enormous. It looks like they could fit all of Abnegation in here too. One of the Candor couples who came in with me is staring like they wish their heads could rotate all the way around. Admittedly I am just as fascinated as they are, but I keep my eyes straight ahead, looking only at the crowds of Dauntless. There is only one thing I need to see while I'm here.

When I don't see Caleb after some of the others have found their family members, I seek out the woman who brought me here. "Excuse me, I'm looking for my brother. He's an initiate. Caleb Eaton. A little taller than me, with dark hair. Have you seen him?"

She looks through the crowd for barely a second. "No."

"Is there someone who'd know where he is?"

"You're really demanding for a Stiff."

"I…" I almost apologize, do exactly what she expects me to do. But Caleb is worth more to me than the customs of my faction. I straighten my back, look her in the eye, and repeat his name slowly. "Caleb. Eaton. An initiate. I'm here to see him and I don't plan on leaving until I do." My heart is pounding, but I stand my ground.

She rolls her eyes and starts to walk away. I follow her past families of Dauntless, children in black talking to parents and siblings in blue and yellow and white. A few have Caleb's height, but I see no one with the Abnegation-short hair he must still have. The woman disappears into a crowd, leaving me to navigate Dauntless myself. Maybe Caleb will take me on a tour once I find him.

I wander into what must be the dining hall. It smells of coffee and disinfectant. The long tables are nearly empty, but I see a group of four Dauntless playing a card game. A girl gawks at me and points. I feel my face get hot, but I stay where I am. One of her friends is a tall, slender boy with a strong profile.

"Caleb?" I ask, though I don't think anyone hears me.

The boy turns to me, and it's him. I can see two silver studs through his left earlobe and there's a bruise under one eye, but without a doubt it's Caleb. Relief floods me. He's all right. Bruised, yes, but he's a Dauntless initiate. That's normal. The Dauntless kids at school were always comparing their various bumps and bruises.

"Caleb!" I call, running toward him.

The girl who pointed at me asks, "Who's Caleb?"

He shakes his head and stands. "I'll be back in a minute," he says to his friends. He points me toward a hallway outside the large dining room.

"What do you want?" he snaps when we are out of both sight and hearing range of his friends.

For a second, I'm too stunned by his tone to reply. He was never, ever so short with me at home. Dauntless, he's Dauntless now, I remind myself. He's probably just imitating the way they speak, trying to fit in. "It's Visiting Day. I came to see you."

"Well, you saw me. I'm fine. You can leave now."

"What? I… I just got here." I want him to know that I took a risk to come here and that he is worth it to me. "Marcus will kill me if he ever found out I came here, and I don't care." I realize this is the first time I've ever called him Marcus and not Dad in front of Caleb.

Caleb doesn't move his gaze from my face, and it starts to make me uncomfortable. He's taking to Dauntless quickly if he's overcome that Abnegation instinct to be submissive.

Crossing his arms over his chest, he says, "Tobias, do you remember what you said to me the night before my Choosing?"

"I… I know we talked about…" What did we talk about? The thing I most remember from that night is how relieved I was that he was in my bed and Marcus was asleep. That he wasn't in pain or danger.

He doesn't wait for me to put an answer together. "Why you stayed in Abnegation. I've thought a lot about everything you said, about staying because you believe in serving others."

"Yes." I breathe out. "I do."

"But that's not the only reason you stayed."

I owe him the truth, the one thing I could never give him until now. "Yes. You're right. I stayed for you. I couldn't leave you alone with him." The healing wounds on my back and torso begin to tingle. I fear some of them may break open right here, seeping dark red blood into my gray shirt.

Caleb frowns. "Remember the night he made me watch when he hit you with his belt?" he asks.

I couldn't forget it. "Yes."

"He said that you still see me as being six years old. Always in need of protection. And you know what? He was right. You thought I was weak, and that's why you stayed."

I shake my head. "No, that's not it—"

"It is!" he shouts. I look around to see if anyone is watching us, but the hallway is still empty. "You thought you were being selfless by staying for me. You weren't. You thought I wouldn't survive without you, but you were wrong."

I hear Marcus in Caleb's voice and feel my throat closing. I have to maintain control. "Marcus is a liar. You know that." He has to. If he doesn't, I am the world's worst judge of character. If he felt that way, why didn't he say anything to me about it? I would have told him the truth.

"I didn't need saving then," Caleb continues, like he didn't hear me, "and I don't need saving now. How blind are you to see that I transferred to Dauntless and still think I need your protection? Dauntless protect others. I'm stronger than you are. I'm doing what you couldn't. You made the wrong decision. You gave up your entire life to be there for me for two years, all because you didn't think I could handle Marcus myself!" His last words echo off the tile floor, and I cringe.

"I'm… I'm sorry." His words are hurting every bit as much as Marcus's hands, but just like I do at home, I push through the pain. "I thought you loved being Abnegation. And yes, I did want you to make that choice, but I wanted more for you to make it on your own, not because of anything Marcus did."

He sighs like he's disappointed with my answer. "Are you even listening to yourself? Half your sentences start with 'I wanted.' What you really love is the idea of who you thought I was. I am Dauntless. Not Abnegation."

I feel unbalanced, like he's struck me with his fist. "I…I didn't mean—"

He interrupts. Another Dauntless trait. "You had my life planned out, didn't you? Abnegation initiation, maybe a place on the city council? Married, two kids, perfect boring Stiff life? You never once asked me what I wanted. Did you even care?"

With every word, he is less and less the boy who climbed into my bed the night before his Choosing. He has become someone I don't know. Worse than that: he's become someone I never knew. I let anger amplify my words. "Of course I cared. How could you think I didn't?"

"You say you wanted me to choose Abnegation because it's who I was, not because I felt like I had to. But you did just that, you fucking hypocrite. I bet you were going to transfer and changed your mind at the last second. You were selfish and you lied to me. You lied to me for years." He steps back. He has our mother's eyes, gold and brown and green, but the look in them is pure Marcus.

"Caleb, I—"

"Four."

"What?"

"My name is Four. I earned it. And we're done here." He starts to turn away. "Don't come back, Tobias. You were never able to see past your own ideas of who I am and what I wanted. I made my choice, and I don't regret it. Faction before blood."

Marcus has won. It took sixteen years, but he succeeded in dividing us, in turning Caleb against me.

He walks away to rejoin his friends. I am too deep in disbelief to do anything but stand against the wall for a minute. Then I make my way back through Dauntless, looking only at the ground in front of me. I want to hit something and scream every swear word I know while doing it. The name plays over and over in my head: Four. I wish I knew the story behind it.

On my way back to the door, I nearly crash into a man about my age. His long dark hair falls into his eyes and his face is a mosaic of piercings. He looks at me the same way the Erudite do, curious and repulsed at the same time. I wonder if he transferred from there.

"What is this, a fucking Stiff invasion?"

I'm past the point of caring about upholding my faction customs in the face of rudeness. "If one Stiff looks like an invasion to you," I retort, "you must not feel very secure as a Dauntless. An invasion of what, volunteers and council members? Yes," I add with sarcasm, "absolutely terrifying. Very fearless of you."

He steps forward and has me spun around in half a second. "I'm sure you have plenty of fears," he says, twisting my arm behind my back. But he doesn't know me. He doesn't know that I have years of practice staying stoic through pain. He could twist my arm all day. It wouldn't mean anything.

"Not…anymore," I say, though I have to clench my teeth around the words.

"Eric!" comes a voice from behind us.

"Bullshit," he hisses into my ear.

Both of us turn to see a woman stomping toward us. She's the one who took me here from the train station. "What the hell is wrong with you?" she snaps.

"Found this one wandering by himself. We handle city security here. For all we know, he's out to sabotage us."

She considers this. I put my head down and act as unthreatening, as Abnegation, as I can. This man, Eric, is shorter than I am, so I hunch my shoulders and curve my spine. "So instead of calling me so I could escort him back, you decide to twist his arm? Something is seriously wrong with you. Fucking psycho." She nods to me as Eric lets go and says, not unkindly, "Come on. I'll take you to the train."

"And stay out of Dauntless. You're not welcome here," Eric says as he shoves me in the woman's direction. I recognize the note in his voice, and I wonder if his father hit him too. I look back at him, but he's already retreated.

"Are you okay?" the woman asks me as I follow her toward the door. "Sorry about that. Eric… I promise we're not all like that here."

"Yes, ma'am, I'll be fine."

"My name's Shauna. Don't ever call me ma'am again," she says in a way that is strict but not threatening.

"Shauna. I'm fine. Thank you."