Desmond stepped into the Hatchery core and the smell hit him first — struck flint and something older, deeper, raw Marrow stacked in crates along the far wall, waiting.
He crossed to the threshold where the settled ribs gave way to the living heart, pressed his palm flat against the warm biometal, and felt the city’s second heartbeat pulse half a breath off from his own.
Heavy in here.
The raw bone sings wrong—wants to be clean or wants to burn.
Make it clean.
Make it fast.
“Slow,” he said aloud to the empty chamber.
“We do this slow or we don’t do it at all.”
The node at his sternum pulsed, unconvinced.
He’d spent the morning on yield against risk, the numbers laid out on salvaged graph paper like a controlled demolition gone backwards.
Forty-two percent refined from raw.
That was the crude method—acceptable when the settlement was twelve people eating twice a day.
Not anymore.
Del’s market ran hot, the Underroost needed Flow to stay solvent, and Talon Yards sat waiting for four hundred ribs he didn’t have.
A deep-refinery would boost yield to forty-six, maybe forty-eight if he grew it right.
Four percentage points sounded small until you multiplied it across two hundred ribs of raw stock.
Four points was the difference between buying more Marrow from the contested field—where the sweeps prowled and the rival crews marked you—and making do with what they had.
Four points was the difference between safe and exposed.
So: grow it deep, grow it right, and never push the rate past what the material would carry.
He pressed his hand harder against the core’s living wall and felt the Marrow-Sense open like a third eye behind his sternum—saw the grain of the structure, the flow-channels where refined stock moved clean, the raw pockets that pulsed sullen and volatile.
There, in the deepest fold of the Hatchery, where the ribs curved inward like a cage protecting its own heart: space for a refinery that could handle bulk.
Space for a bomb, if he was careless.
He began.
The work was slow and sick-making in a way combat engineering never was.
Setting a charge, you knew the moment it went wrong.
Growing Marrow into a refinery—coaxing the raw bone to branch, to hollow, to form the filtration lattice that would strip impurities and leave pure stock—you felt it resist.
Felt it want to collapse inward or flash hot or simply stop, inert and useless.
Desmond worked with his eyes half-closed, the Sense more reliable than sight, his hands on the core and his breathing gone shallow.
The node at his sternum burned like a coal that wouldn’t bank.
Sweat ran cold down his spine.
Grow it there.
Yes.
The channels want to fork—let them fork, I’ll hold the flow even, don’t fight me, we’re the same thing—
The refinery took shape over two hours that felt like six.
A vascular chamber sunk into the Hatchery’s heart—raw Marrow fed in at the top, refined stock drawn off at the base, and in between a lattice of filtration ribs so fine they looked like frozen smoke.
Beautiful, if you forgot what happened when volatile material ran through a living structure faster than it wanted to go.
He stepped back, shaking, and put his hand on the nearest settled rib to keep himself upright.
His knee screamed.
The node’s warmth had spread across his whole chest, a flush like fever.
A hum rose from the deep-refinery—its first note, low, dry, steady.
A quarter-tone higher than the Hatchery’s baseline, which meant it was working, processing, hungry.
Good.
Feed me.
I can take more than this.
Push me and I’ll give you fifty percent, fifty-five—
“No.” His voice came out hoarse.
“Forty-six is the line. Get faster updates on g.com.
That’s the line and we hold it.”
The core pulsed, dissatisfied, but the note held steady.
He walked the perimeter on legs that didn’t want to carry him, checking joins, reading the lattice, and stopped at the narrow cleft he’d built into the east wall—a blast-channel opening onto a jettison chute angled down toward the water.
Old demolition doctrine: if you’re working with something that wants to burn, build it a door to leave through.
If the refinery went critical, if the raw stock flashed over, if he pushed the rate too fast and the whole chamber went up—he’d have maybe eight seconds to throw the burning mass clear before it took the Hatchery core with it.
Eight seconds.
He’d seen men die in less.
He ran his hand along the chute’s edge, the Marrow still warm from growing, and told himself it was insurance he’d never use.
Marce found him an hour later, sitting against the core wall with his eyes closed and his hands still shaking.
“You look dead.”
“Not yet.” He opened his eyes.
Marce stood in the chamber entrance, arms crossed, wearing the flat look he wore when he was deciding whether to shout at Desmond or let it go.
“Refinery’s up,” he said before she could choose.
“Yield’s forty-six percent.
We can process the backlog in three days at safe rate and have stock to spare for Talon.”
“Safe rate,” Marce repeated.
“Define that.”
He told her the numbers—flow volume, temperature ceiling, the speed the lattice could handle without stress-fractures forming in the filtration ribs.
Marce listened without interrupting, his eyes on the refinery’s faintly glowing lattice, and when Desmond finished he dipped his chin—once, sharp.
“That’s the line.
You don’t cross it.”
“I know.”
“I’m not asking if you know.
I’m telling you the line, and I’m telling you I’ll pull the raw stock myself if I catch you running hot.” His voice was flat, final.
“This thing sits at the heart of the settlement.
If it blows, it takes the Hatchery, and if the Hatchery goes we all go.
So you run it at forty-six or you don’t run it at all.
Say it back.”
“The rate.
Safe.
Don’t cross it.”
“Good.” Marce crouched beside him, close enough Desmond could see the old burn scar along his jaw, the grey threading his temples.
“You built something good here, Desmond.
Don’t burn it because you got greedy for four more points of yield.”
Desmond met his gaze and nodded.
Marce held it a moment longer, then stood and walked back toward the Wingward, bootsteps ringing off the Marrow ribs.
He sat alone in the refinery’s hum and told himself she was right.
Forty-six was enough.
There was no number above it worth the risk.
The node at his sternum pulsed, warm and patient, and didn’t argue.
The refinery ran beautifully.
By evening the backlog was half-processed, raw Marrow flowing smooth, refined stock pooling clean in the collection chamber.
The note held true.
No stress in the lattice.
Desmond walked the circuit every hour, checking temperatures, reading the grain, and found nothing wrong.
Bram found him on the third pass, grinning like he’d just won something.
“Del says we’re up twenty percent on yesterday’s yield.
That’s—boss, that’s a week’s margin in one day.”
“It’s the safe rate on decent raw stock,” Desmond said, but he couldn’t help the faint tug at the corner of his mouth.
“Nothing magic about it.
Just doing it right.”
“Right.” Bram stepped closer, his eyes on the refinery’s glowing lattice, the awe plain on his face.
“Can you teach me to run it?
I mean—I know I’m just the dock hand, I know I don’t do the Marrow work, but if you’re gonna be busy with Talon, maybe I could—”
He trailed off, suddenly uncertain, and something loosened in Desmond’s chest that had nothing to do with the node — just a kid who wanted to learn, asking straight instead of assuming no.
The boy was eighteen, maybe nineteen.
Crew from the first salvage days, before the Roost was anything but a platform and a bad idea.
Good hands, a memory for numbers, and the kind of fearless that came from being young enough to think nothing would kill you.
“Tomorrow,” Desmond said.
“I’ll walk you through the safe cycle tomorrow.
You’ll run second shift while I handle the build.”
Bram’s grin went wide enough to split his face.
“Yeah?”
“Yeah.
Don’t make me regret it.”
“I won’t.
I swear, boss, I’ll—” He caught himself, visibly steadied, and nodded once with exaggerated seriousness.
“Tomorrow.
I’ll be ready.”
He turned and jogged back toward the Wingward, already talking to himself, already running through the steps Desmond hadn’t taught him yet.
Desmond watched him go and felt the warmth at his sternum pulse, approving.
The boy’s eager.
Teach him right.
We need hands that aren’t just yours.
“I know,” he said quietly.
“Tomorrow.”
That night he stood alone in the deep chamber, the refinery humming its steady note, crude Marrow feeding smooth and the yield pooling clean.
The safe rate.
Marce’s line.
Enough to feed the settlement and still have margin.
He put his palm flat against the refinery’s outer wall and felt the heat of the work, the lattice singing under load, the eight-second failsafe waiting silent in the dark.
The old scarcity reflex whispered at the base of his skull—push it a little, just a little, fifty percent would buy you days, would buy you safety, would mean you never have to go back to the contested field—
He pulled his hand back and shoved the thought down hard.
The rate was the line.
Bram was running second shift tomorrow.
The city was solvent and the refinery was good and there was no reason in the world to push it faster.
Warmth pulsed at his sternum, patient as a held breath, and offered no argument.
He walked the seams one last time, counting joins, checking the blast-channel he’d never use, and told himself it would hold.
HATCHERY CORE STATUS — DEEP-REFINERY OPERATIONAL · Refining yield 42% → 46% (safe rate) · Raw stock 84 ribs queued, stable · Refined stock +18 ribs processed (day one) · Lattice integrity 100% · Temperature nominal · FAILSAFE: blast-channel + jettison chute installed (8-second manual activation) · HAZARD ADVISORY: raw Marrow in bulk is volatile — safe rate ceiling 46%, DO NOT EXCEED · Next shift: Bram Khoury (training run, supervised) · THE ROOST SAYS: Deep-refinery grown.
Yield up to 46%.
Raw bone runs hot in here—feed me slow.
Push me and I’ll burn.
I built you a door to throw the fire out if you’re fast enough.
Don’t make me use it.