Only the strongest, most musical hands can play guitar well. Me, I've got the vague capacity for a few Barre chords, but if you need to see an actual guitar player, someone who could be in a band, you'd have to meet Eli.

Presently, he shoves a hand into my face. "I've been playing guitar for three hours," he says. "I think my calluses are about to bleed."

"Shut up," I say, batting his hand away but not swaying from my perch on the living-room recliner. Eli's calluses are little pieces of granite implanted in his flesh; I don't think he feels anything in his hands at all anymore.

"Do you have a lot of homework?" he asks. "I can help."

"I'm good."

Comedy Central is advertising "The Daily Show" until my cerebral brother changes the channel to CNN.

Immediately, I change it back.

"We're not watching that," I say.

Eli pauses, blue eyes unfocused. I recognize the vacant look, and it scares me. "I want to."

"You know what that does to you," I reply.

H's quiet again. I turn the television off.

"Wanna jam?" he bursts after three minutes of obtrusive, uncomfortable silence.

I shrug. "Sure."

Eli may have the manly, tough, guitar-playing hands, but even his musical prodigy cannot challenge me on eighty-eight beautiful ivory keys. This is, of course, due to my brother's extreme veganism, in which he abstains from all animal-related foods, wears no leather, and, of course, won't play a piano.

Our rec room, situated in the middle of our complicated apartment, has circular walls. This works to drown out Manhattan traffic, and the consistently illegal beeping. Eli can't work well in loud situations, so his bedroom is farthest from the window.

My brother plays complicated chord progressions and interchanges them with subtly beautiful picking. I plunk clumsy hands over my ivories and hope not to tarnish the crazy melodies of Eli's mind.

A tiny news radio in the corner buzzes with white static and then bursts to life, declaring an imminent search for a serial murderer in the Bronx. I recall removing it days ago, placing the antique artifact, leftover from my grandfather's home, in my own room.

"How'd that get in here, Elijiah?" I ask. His guitar has stopped. Sitting at my piano bench, my back faces him, and I can barely muster courage to turn my eyes on my brother. I can see exactly what's before them already, as imaged are projected onto my eyelids as I blink, from all of the pessimistic parts of my brain—and there are many more of those than optimistic ones.

My brother's aged acoustic guitar rests at his feet, strings down, and his long, thin body looks too tense not to crack into pieces. His musical hands are clenches so tightly together that his knuckles have been bleached white by strained veins, and indentations and wrinkle lines scatter his face as his porcelain blue eyes close so tightly that he can't convince himself to open them again. He's not moving, not even shaking from the exertion of his taut muscles, and I realize, irrelevantly, that running five miles daily on Manhattan beaches might benefit him more than it inconveniences me.

I can hear my breathing, normal and even and rational (or at least a reasonable facsimile) in my own ears like hurricanes blowing my over, and then all I can hear is a low, painful groan from my brother's mouth, like he's feeling all the pain of the world.

And he is.

We do the usual. We take Eli to the doctor, and he gives us drugs to give Eli, who would surely protest were he coherent. He can stay at home as long as it doesn't get worse.

It can only get better, they say.

All I can think is that there was a reason why they used to call Eli "Sunshine," and never branded me with that nickname.

"Yeah, Eli's volunteering for the soup kitchen on Tenth again all day," I tell Thom and Marie that morning when I meet them at their apartment door. It's three floors from ours, so we've walked to school together for all of our years. I've told this lie more than a dozen times since Eli turned fifteen and started having what Dr. Rosenberg referred to as "episodes."

"He never mentions it," Thom says. We match in our private-school uniforms of black shoes, black socks, navy pants, white shirt, navy tie. Mine is undone around my neck; Thom's is knotted tightly round his.

"Well, you know, humble and meek and all that crap about inheriting the Earth," I say. "Personally, I don't think there's much worth inheriting."

Thom laughs. "I can't disagree with you, but Eli would."

"He's too busy spooning out soup to the kind of people who would beat him up and steal his money," I say. It's so easy to lie now—Eli's got me trained. I don't even feel the guilt anymore.

"Well, that's why we love him," Marie remarks.

Thom and I nod in acknowledgement.

Marie stops at Starbucks. Thom goes inside with her. I stand outside, surrounded on all sides by rushing people, and wonder if any of them will ever feel the way Eli does right now. I wonder if they pause for mere seconds in their self-important reveries to mourn for the sad fates of peoples in poor, war-torn countries, of children dying, of little six-year-old boys without fathers and little six-year-old girls who feel like no one will ever love them.

I wonder how strong their hands are, if they can play guitar like my brother.

But mostly I just wonder why any of this happens, and, like usual, there's no answer that I can find.

More people ask me where Eli is that day than ask me how I am. I just say "volunteering" and turn around. I think I'm known at St. for being curt, for being the ideological opposite of Eli while I could be his identical twin physically. I don't care much. At lunch I find the only table I ever sit at, with Thom and Jack and Jonah.

"Hey, guys," I say.

"Where's Eli?" asks Jonah. Being a year younger than all of them, I came as a part of the Eli package, and got thrown into his circle of friends by accident. I like them, even love them, and there's no use in thinking about what may have been different if I'd plowed my own ground here. That's what makes Eli how he is.

"Volunteering," Thom answers, and I could hug him.

"Saint Elijiah the Pure," Jack declares in a regally deep voice.

"What does that make him?" asks Jonah, gesturing vaguely to me.

Jack and Thom ponder for a moment.

"He's Saint Elijiah the Pure's younger, less pure brother," answers Jack brainlessly.

My smile isn't even forced. It's okay.

That day in Advanced Math, the only thing that I write in my notebook that makes sense to me is f(eli)=myself.

I think I understand Calculus just fine.

Mom usually stays home from work when Eli has one of his days, so I'm not surprised to see her on the couch watching Dr. Phil when I finally get home from school.

She looks up, and the guilt hits. I don't know why I feel it now. Her blue eyes are so tired, her blonde hair so pale that it might be going gray. Her already small figure looks diminished under a green knitted afghan from Eli's best friend Vanessa.

"Hi, sweetie," she says. Her voice sounds rough, like she's ben neglecting her cough drops and crying.

"Hi." I drop my books in the basket in our foyer. When I come out, I raise my eyebrows, silently asking.

"Well, you know," she says. "But he's better. He's talking. You can see him."

I nod in response and pace the hall to his room. I hesitate with one hand on the wrought-iron knob. It's cold, and it's mid-December, and it feels like it inside, despite the heater.

Or maybe that's just me.

Quietly, I step cautiously into the room, afraid to startle him.

"Hey," he says.

"Hey," I say.

"Do you have a lot of homework?" he asks.

Inexplicably, there are tears in my eyes, because I cannot say that I'm good. With everyone else, it's an easy lie, a white lie, a lie that I've told so many times that it's become a reality of mine. With Eli, with my brother, I can't lie. Not when Eli knows and feels so much truth.

"I've got some," I say. Truthfully, it's an English essay and a full page of Calculus problems, but I'm being optimistic for Eli. He taught me the difference between optimism and lying.

"I can help," he offers. I noticed, in his room lit dimly by two strings of blue Christmas lights, that his blue eyes seemed more muted than usual.

"Okay," I acquiesce, and a tear falls down my cheek. His voice sounds like a void of his normal tone and it breaks my heart a little. I think that he must feel just like this, only tenfold a million times.

And for all of my jealousy of my big brother, Saint Elijiah the Pure, I love him with a fierce admiration that keeps me grounded. I wouldn't want his place; I couldn't fill it as well as he could. And for the teasing and the exasperation, I can never say that I'd want to feel the way he does, so deeply and fully, for everyone in the world who's ever felt any pain. And I can't say that I don't feel a little guilty, because some of that is mine.

But I would do anything I could to change that, if it could lessen the burden my brother so unusually carries.

"Want to do it now?" he asks me.

My breath is shaky, but somehow my voice is steady as I say, "Not yet. Wanna jam?"

"I can teach you something on the guitar," he says. "Wanna learn the E-flat diminished-ninth chord?"

I smile without realizing it. "Sure."

His own smile is crooked, a perfect replica of my own (or maybe I'm the replica of him). "Sure you can handle it, Barre chord boy?"

"If you can take it, I can take it," I affirm.

He strides easily across the room and picks up the acoustic from its makeshift stand—or simply a clean spot to lean against the wall.

"Now, Eben," he says, "let's see if you're ready to become a real man."

"Bring it," I joke. "I'm ready."

That, that simple four-word sequence, is the difference between optimism and a lie. Eli knows this; his smile increases by ten watts.

"You'll make a great guitar player," he says.