One Saturday night later that winter, Robert Black invites me and Caleb to have dinner at his house with him and Susan. The Black family has lived a block away from us my entire life. I don't even remember a time when I didn't know Robert and Susan. Our mothers were friends. Susan jumped rope with me when we were little, had macaroni fights with me in art class, and copied my math homework when we got older. If I had a best friend, she would be it. The one thing I've never been able to tell her, though, is the truth about Marcus.

In the weeks leading up to our Choosing Ceremony, I'd mostly avoided her. I thought she'd be able to read my indecision just by looking at me. But if she noticed, she didn't say anything. I'll never know if she kept quiet because she didn't notice I was torn between factions, or if she kept quiet because she did. Regardless, when we both chose Abnegation, she was at my side from orientation through initiation. We did our community service projects together and even sat together at the initiation ceremony. Sometimes I think the real reason I don't want her to know about Marcus is that she personifies everything that is good and beautiful about Abnegation. Knowing what it hides could make her question all the ideals she upholds. I don't want that for her.

Mr. and Mrs. Black are at a gathering for council members, along with Marcus. We have the house to ourselves. Robert and Susan still live in their family home, per Abnegation's rules. There isn't enough housing for every new member to get a house of their own, so Abnegation-born members stay in their family homes until they marry. The house is nearly identical to mine in layout and furnishing, but there's something about it that seems warmer, more welcoming. I feel relaxed here the way I should in my own home. This is a house where the family doesn't question their love for each other. Where arguments get settled with words instead of fists. Robert likes to cook, and the smell of baking bread always hangs in the air.

After dinner, we all clean up, then the four of us settle in for our ongoing Pictionary tournament. The teams are always the same: me and Susan versus Caleb and Robert. Susan is a terrible artist, and while she usually has a good sense of humor about my guessing that her porcupine is a cactus, she seems a little restless tonight.

When Robert and Caleb are beating us by ten points, she turns to me and says, "I think I'm done. Tobias, do you want to go for a walk?"

"Go," Robert mouths to me when I glance at him. "Caleb," he says, "play chess with me. Susie never wants to."

"Yes, I'll go with you," I tell Susan as Robert trades the Pictionary cards for a chess set. We pull on hats and scarves and mittens and step into the clear night.

"Thank you for coming with me," Susan says as we walk away from her house. "I just get tired of losing. We need to find a new game to play."

"I don't mind," I tell her. "It's nice to see you and Robert."

"You haven't been over in a while," she says. "Have you been busy with the volunteer team?"

So she's noticed. "I…ah… Yes." It's not entirely a lie, so I feel less guilty about telling it than I should. Still, I hate that she sees I've been spending less time with her than usual. It's not what I've wanted. Besides Caleb, Susan is the only person whose presence makes me feel happy and comfortable.

I turn the conversation towards her. "How about you?" I ask. "Are you still interning with the council?"

Nodding, she replies. "I am. It's interesting. A lot of paperwork, though." She laughs. "Very glamorous," she adds with a touch of sarcasm. "But, Tobias, I… I wanted to walk with you to ask you something." She stops beneath a streetlight. Her breath forms a plume of fog between us.

"Sure," I reply. "What is it?"

"I…would you… Erudite is sending books over to the Abnegation library next weekend, and I wanted to volunteer to sort and shelve them." She takes a deep breath. "If you're available, would you like to come with me? Not with Caleb and Robert. Just us."

This should be a thrilling moment. Instead, disappointment freezes me in place. Not because of Susan, but because I know I can't say yes to her. I want to more than anything. I want to do normal things with this pretty girl I've known and cared about all my life. I allow myself a minute of fantasies: shelving books together, kissing, a wedding, a home of our own. But then I think of Caleb. I know he would like to see me and Susan together. That part's not the issue. Time spent doing community service with Susan is time I can't spend at home protecting Caleb from Marcus. It would only be an afternoon, but Marcus could kill Caleb in minutes.

"I can't. I wish I could," I reply, and having to say it stirs anger in my gut. This is another piece of my future Marcus has taken from me. Other people in my initiate class have started dating, doing community service together and sharing meals at each others' houses. I want that. I want it with Susan. Maybe we could be more than friends, maybe not, but what I want doesn't matter.

Susan looks away. "It's all right."

"No," I tell her. "It's not you at all. I… I like you. A lot. When I'm with you I… I always want to feel the way I do when we're together. And I want to spend more time with you, but I can't right now."

She seems confused. "Why not? Wouldn't you be volunteering anyway?"

I try to work the words in my head into something that she'll understand, and that won't hurt her. "Not right now. I'm… Right now, I'm…ah… Caleb is relying on me a lot." Instantly, I regret saying it. Now she's going to think I'm blaming Caleb for not wanting to do a service project with her. "No. I mean, he's been so busy with finishing his volunteer hours and school that I've had a lot more to do around the house."

"Oh." Susan is clearly disappointed, and that makes me feel worse. She's going to think that I'm not interested in her. Any chance I have at exploring our relationship beyond friendship is about to disappear.

"It's not you," I reassure her. "The timing is just really bad. Until Caleb chooses, I only have time for my regular volunteer duties."

"Duties that are going to go away in a few months." She sounds dubious and folds her arms over her chest.

"Yes. I…I can't really explain better than that."

"Come on, Tobias." She knows I'm hiding something from her. "We've been friends forever. If there's something wrong, you know you can tell me."

"Everything's fine."

"Do you not trust me?"

That question feels like she sent the cold, damp wind straight into my chest. Despite the secrets I keep from her, I know I could trust Susan with anything. "Of course I do. But you'll have to trust me, too. I do want to volunteer with you and see if maybe it could be more. You're one of the best people I know. I always have a good time when Caleb and I come over. I just can't make it more than that right now."

Susan looks as dismayed as I feel. "Maybe we should go back."

"I'm really sorry," I tell her.

"It's all right," she says, though I can tell she doesn't fully mean it.

We walk back toward her house and don't say a word to each other. Just before we go in, she stops short of opening the front door.

"You're one of the best people I know, too," she says. "And I can't be upset that you have to take care of your family first. Caleb's Choosing Ceremony will happen before we know it. I'll be here when it's done."

I melt inside when she says that. "You don't have to wait for me."

"I want to. " She smiles. "I think you'll be worth it."

If I were Dauntless or maybe Candor, I would grab her and kiss her right now. And when I was done, I'd tell her everything. Even if she couldn't offer me advice, she'd listen and believe me. She'd help me make a plan to save both Caleb and myself. But her father is on the city council, and she's looking at a career there too. Right now, the best I can do is keep her from becoming collateral damage. I take her hand, which I know is aggressive for someone I'm not officially dating, but I hold it loosely so she can pull back any time she wants. She doesn't let go.

"What are you two doing out there?" calls Robert in a teasing voice.

Our moment broken, Susan rolls her eyes. "I am going to stuff a dishrag in his mouth when we get inside."

I grin. "I'll help."

Susan laughs and squeezes my hand before dropping it. "Come on. Let's go in."

I feel warmer, lighter, as Caleb and I walk home later in the evening. Susan's promise gives me hope. I'd always pictured myself living alone for the rest of my life, but if Susan sees something worthy in me, maybe I'm not as much like Marcus as I thought. I guess I'll find out in a few months.

Though Caleb is stronger and taller now, with only a few months left before he chooses, I still put myself between him and Marcus. Caleb, like me, has adopted the habit of only telling Marcus what he absolutely must know as far as school or our friends are concerned. One night in the spring, I hear Marcus pull Caleb aside as I'm washing the dishes. Although I don't hear Marcus's words, I know the tone of his voice. He's upset.

I shut off the water and hear the anger in Marcus's voice intensify. "I don't care how the other students in your class did. When you bring home grades like this, it's further proof to Erudite that they should be the governing faction. When you prove to them that you can't match them intellectually, that strengthens their argument!"

Caleb is holding a paper that he tosses to the side. "It's just one test! I'm not going to hurt our entire faction because of it."

"If it's 'just one test' to you and every other selfish child in Abnegation, it is going to hurt the entire faction."

I can't see Caleb's face because I'm standing behind him in the kitchen doorway, but I know that whatever he does pushes Marcus over the edge. Marcus is quick in grabbing Caleb by his collar, but I am just as fast and reach him in three long steps. I take Marcus's fist and pry it off Caleb's shirt, forcing him to turn and face me.

"Leave him alone," I say. It's not the most commanding I've ever been, but I get my point across. "Caleb always gets—"

Marcus strikes me across the mouth and I stumble to the side. As I'm running my tongue over my teeth to check for blood, he hits me in the stomach, just under my ribs. I fall back and gasp for air.

"Stay out of this, Tobias, unless you want to take Caleb's punishment for him."

Until Marcus said that, I never knew how much anger I carried, or what I could do with it. But it's not just anger, it's my need to protect Caleb, my promise to myself. To both of us. My field of vision narrows and I feel a tempest at the back of my brain. Lightning sparks in my hands.

Standing as straight as I can, breathing hard, I look Marcus in the eye and say, "Go ahead." Kill me, I think. Because I'm willing to die right now if it means Caleb can get away.

Marcus blinks. I think he's trying to figure out if I'm serious.

He should know better than to doubt me.

Any hesitation Marcus had disappears in the next second. He aims his fist at my face, and for the first time, I don't raise my hands to protect myself. Instead, I evade him. I have never done that before, never tried to avoid his hits completely. I've always just guarded my face and prayed he wouldn't do too much damage. But now I have defied Marcus by stepping out of his reach and not letting him hit me, and that can only mean more pain. I make the mistake of looking into Marcus's eyes and see nothing but hatred and fury.

"Coward," Marcus says, like the word is a weapon. He reaches for his belt buckle, working it backwards as he speaks. "If you think you're so brave you'll take Caleb's punishment, then you take it like a man. You don't run away from me like a little boy."

I watch him fold his belt in half. "Caleb, get out of here," I say, my eyes on Marcus's hands.

"No!" Marcus shouts. Guilt grips my heart as I watch Caleb. "You stay right where you are. You're as much a coward as your brother."

"I'm not going anywhere," he says quietly, but I can't tell if it's to reassure me or to obey Marcus.

"Take off your shirt," Marcus orders me.

"No." I cross my arms over my chest.

"It wasn't a request, Tobias." His voice is controlled. It's more terrifying than if he were screaming at me. "You'll take yours off, or I'll have you take Caleb's off for him."

I look from Marcus to Caleb. Both are still as stone.

I consider my options. I could reach out and hit Marcus. He wouldn't expect it. But even if I did hit him, that wouldn't make him stop. It would only make him angrier, and he'd direct that anger at Caleb. I could grab Caleb and run, but there's nowhere for us to go. Marcus may be cruel, but he is not stupid. He knows I have nothing to bargain with here. Nothing to offer him that would save both of us.

If Marcus is going to beat one of us, I can't let it be Caleb.

Without a word, I pull my shirt over my head and hang it on the back of one of the dining chairs.

"Turn around and put your hands on the table," says Marcus. Then to Caleb, he says, "If you move, you get two lashes for every one I give Tobias."

I don't know if Marcus counts, but I do. Eighteen. One for each year of my life. Somewhere around eight, maybe ten, the pain becomes my everything. I feel like I'm immersed in fire. But I hold my shouts of pain in my throat, stifle them with my teeth, for as long as I can. I am determined to show Caleb my strength.

There is a second when Marcus pauses, and I see Caleb step toward us. "No!" I gasp, remembering Marcus's threat. "Don't move. I'll be—"

My reassurance to Caleb that I'll be okay is cut off with another blow from Marcus's belt. It lands on top of an already open wound and I scream. My knees wobble. The marks left by the metal edges of his belt buckle are stinging on every inch of skin from my shoulder blades to the base of my spine. I can already feel some of the cuts tightening, trying to form scabs. Scars over scars. My back feels sticky from blood and raw from the breeze that comes off our ceiling fan.

"Look at your brother," Marcus says to Caleb when he is done. I want to give in to the pain, to pass out, to throw up, but I steady my breathing and rest on my forearms. I am not going to let Caleb see me give in. "It doesn't matter how many of your punishments he takes. He didn't do this out of selflessness. He did it because he thinks you're still six years old. He thinks you're weak. And you are. You're weak and you're selfish, letting him take your place."

His words travel straight up my spine like I've touched something hot. How dare he use this moment to try to divide us, and to tell such lies. I pull myself off the table, though I can't stand straight. Marcus grabs my arm and pushes me forward. Caleb catches me. He's strong. Sturdy.

"What kind of man are you," I say to Marcus between panting breaths, "to hit your own children?"

"Tobias, stop," pleads Caleb.

"What kind of…justification…do you even have?" I continue.

If my words had any impact on Marcus, he doesn't show it. "Get out of my sight, both of you," he orders. "And I don't want to see either of you until tomorrow morning."

"Come on," Caleb says quietly. With his support, I make it upstairs into our bathroom. He starts the shower and turns the water so it's lukewarm. "Wash your back. I'll get the bandages."

The best I can do is stand under the spray. I can barely lift my arms, much less reach around my back. Caleb leaves for a minute. When he returns, he takes the soap from me, gently, like he's trying not to scare me.

"I'll…I'll get this," he says. He turns me to face the wall of the shower. I'm so worn out that I don't even care that I'm naked in front of him. The soap stings, but I bear it.

"You know I don't think you're weak," I whisper when he turns off the water. "Never. Never have."

"Shh. Not now." He holds out his arm so I can balance as I get out of the shower. I put a towel around my waist. "Sit," he says. He took the stool from Marcus's bathroom and placed it in ours. I let him dab peroxide on my wounds and wrap gauze from my back around my chest when the cuts are too close together to place an adhesive bandage. He works patiently, with steady hands.

"Okay," he says after he's used most of the gauze from our hoard of first-aid supplies. "Just bandages, no stitches." Erudite would recruit Caleb for their medical program in a second if they knew he could already make small, neat sutures. "That should get you through. I'll go to the clinic and get more tomorrow." He kneels and digs into the back of the cabinet under the sink, where we keep threadbare rags and a few cleaning products. "And take these." From inside a folded rag, he pulls two white pills. Painkillers. Marcus doesn't allow them in the house because, he says, they take you out of your mind. The pain he inflicts is supposed to remind us to do better, follow more rules, be silent and subservient and orderly. We don't deserve a reprieve from it.

Out of my mind is exactly where I need to be right now.

"Thank you." I swallow the pills with a cup of water Caleb hands me. Then we sit in silence in our bathroom until I start to feel the effect of the medication, a calm that settles like a heavy blanket. I get up from the stool and stumble. Caleb, watching for Marcus, guides me into my room. I lie face down on my bed and sleep for the next twelve hours.

The next day, I realize that Caleb never said anything in response when I told him I didn't believe he was weak.