Late for my curfew and trembling, I grasp the doorknob that is not a doorknob.

This is the Machinist Quarter--only a tiny sliver of Netherview Station's Ring B, though I'm one of the few boys I know who has ever been outside it. Fo-grav stays off in the Quarter; our only simulation of gravity is the 0.25 g of natural centripetal acceleration born of the station's rotation and our two-kilometer distance from the hub. We joke that this is why it's called the Quarter. It sure isn't called that after the ratio of its volume to the station's.

The cabin I share with my father Thomas lies in the Inclined Plane branch, third transverse, twelfth hatch on the left. Standing at the hatch, I straighten my billed cap and smooth my coverall--each emblazoned with a right triangle stitched in dove-gray thread, representing our ward--and gently turn the knob. Recessed lights at deck level cast my diffuse shadow up the bulkheads to either side of me. The knob operates as if it were mounted on a genuine mechanical axle, though of course it isn't. A dumb mechanical doorknob wouldn't unlock to my touch alone, or Thomas's. I hate the doorknob. I hate the deceitfulness of it, the way its homogeneous smart matter mimics the virtuous and differentiated and pure. I hate what it conceals. I hate it for not keeping me out.

With a silent prayer to the Builder, I push the hatch open. It swings inward on soundless, lying hinges. I tread lightly inside, in case Thomas is sleeping, the nonslippers on my feet helping me keep my steps short and low. But as I round the door I see Thomas sitting up on his bunk in his short gray underall, watching me enter. The door closes itself behind me, which no door should do unbidden. The cabin is narrow and unadorned but for a diagram of the Six Fundamental Machines affixed to the rear bulkhead, and a small wooden chest bolted to the deck beneath it. The air reeks of a coppery sourness that matches Thomas's narrowed glare. The cabin is so tiny I could reach out and stroke his curly, graying hair if I wanted, but that's an urge that no longer seizes me often. Anyway, the days when I could reliably charm him out of his anger are long past.

"You're late, son," he says. He's squinting at me now, eyes unfocused, the way he does sometimes. He doesn't even glance at the chronometer on his wrist--a true mechanism, with tiny metal gears and not smart matter inside, a symbol of his status as a merchant trader. "It's past your curfew."

"I'm sorry," I say, turning my back and reaching for the crank that will fold my bunk down from the bulkhead opposite his.

His voice grates out in sharp, tight bursts like the strokes of a rasp on iron: "If you were sorry, you'd have been on time."

My shoulder blades prickle. I say nothing, cranking down the bunk.

"Jude, you're fifteen years old," Thomas says. "Why do you think you still have so many rules? Why?"

I try to shrug, but the effort feels jerky, like the gesture of a marionette. "I was waiting my turn at devotions," I say, clinging to the false crank. "You know--with Nic and the rest. But the Foremen wouldn't--they stayed past their time, and we, well..."

Thomas has risen, his voice at the back of my neck, shivering my spine. "I was out looking for you. I spoke to Nicodemus an hour ago. In Plane, not at gymnasium."

My blood runs chill. That's two lies I've told, and he's caught me in one already. Nicodemus is my best friend, or used to be, but lately I've been avoiding him. We were up late working on our motors in the schola a couple of weeks ago. He was helping me get the timing right on mine and his fingers brushed the back of my hand. It was just an accident. We've been friends all our lives, but it was like seeing him for the first time. I wanted to touch his face, though I didn't let myself. The scary thing was, it didn't feel wrong, and that scares me all the more.

Of course I can't explain this to Thomas. Nor can I explain why more and more I can't force myself to evening devotions on time. The cleansing room where we change and shower is like a chamber of horrors. None of the boys seem bothered by disrobing in front of each other, but it bothers me acutely. Letting them see my body makes me want to tear my skin off.

My bunk is halfway lowered. I want to turn and defend myself against Thomas's implicit accusation but a bolus of confusion clogs my throat. Words swarm like dust in my brain, eluding my grasp. Why do I have to explain any of this to him? Why doesn't he just know? And why is it his business?

"Great Builder, Jude," Thomas says at my back, "if you have to lie to me, how can I trust you at a job?"

My shoulders stiffen, my head half turns.

"That's right, I've lined up a job for you. Do you understand, son? At the hub."

A sick despair flares in my gut. Outside the Quarter? Could things get any worse?

"I need you up early, and fresh, but you're out doing Builder knows what when you should be in bed. Did I raise you to be this way, Jude? Did I?"

Tiny flecks of spittle flense the back of my neck. I was at my devotions, I really was, I want to say, but the words won't come.

"Answer me when I speak!" Thomas says, seizing my arm and spinning me around. My cap with its Inclined Plane insignia flies off my head.

The skinny legs tensed for violence, the slow ripple of his round, protruding belly, the sharpening rage on his gray blade of a face--I'm bigger and taller, but I might as well be five again for all that I can stand up to what's coming.

He shakes me. "You will honor your father, that your days may be long upon the earth!"

Saline globules tremble at the corners of my eyes, watery jewels sparkling across my sight. The words burst out before I know I'm speaking: "There's no earth here, only metal."

My father's face flushes livid. He spins, hurling me across the cabin--not difficult, since my weight is just twenty kilos. I sprawl across my father's bunk, all gawky limbs and terror.

I roll over and there he is looming above me, fists raised and shaking. It's been months since last he struck me, an improbable lucky streak which now seems about to end. But he lowers his arms and leans over me.

"The Wrecker's in you, boy," he says, shaking a finger. "You pray hard and shake loose his grip. Pray to be made square and true. Tomorrow more than ever, you need the Builder to be with you."

And now he's pulling on his coverall and leaving the cabin to stalk off his anger, the hatch snicking shut behind him like a quiet tap to a finishing nail. Alone, I flow off the bunk to the floor, to my knees, to retrieve my cap and pray.

I'm out of true and I need fixing. Through shuddering tears I pray for the Builder to make me a better son, a stronger laborer, a whole person. I pray for his protection, both physical and spiritual. I pray for reassurance that Thomas doesn't really mean to send me alone among the Sculpted in the morning.

When I finally crawl into my bunk and wrap the blanket around myself, though, it's not the Builder with his Machines I picture watching over me in the dark. It's my departed mother Kaiya, angel wings spread above me in a canopy of white.