The tunnel breathed.
Not like a creature, not like a monster—there was no will in it. Just a slow exchange of air forced through stone by pressure, heat, and a thousand tiny imperfections no one had ever fully sealed. Every few seconds, a faint draft passed through the corridor, carrying the mixed scent of damp earth, mineral dust, boiled roots, and old smoke.
Luke had grown up with that smell.
He could tell the work cycle by it alone. Early drafts were sharp and cold, pulled from deeper stone. Mid-cycle air grew warmer and heavier, thickened by bodies and cooking pits. Late-cycle air carried fatigue. Today's air felt balanced—people were working, and nothing had gone wrong yet.
That mattered.
The lamps along the tunnel walls glowed a dull amber. Low-grade mana crystals sat inside metal cages, cracked and repaired so many times that no two looked alike. Their light didn't form clean shadows, only faint suggestions where edges should have been.
People moved anyway.
Men and women stepped around uneven stone and warped supports without looking down. Children darted through side passages, bare feet slapping softly against the ground, their laughter bending oddly as it echoed through branching tunnels. No one scolded them unless they crossed into marked paths.
Luke walked among them, carrying a crate hugged close to his chest.
It was heavier than it looked.
"Careful there," an older woman muttered as she passed, balancing a basket of fungal bulbs on her hip.
"I've got it," Luke replied automatically.
He shifted his grip and adjusted his pace, letting the weight settle into his shoulders instead of his arms. The crate held scrap—bent plates, worn gear teeth, broken housings from things that had once mattered. He didn't know what most of it had been used for.
But he could tell how it had been made.
He always could.
Hearth-Deep wasn't large. By surface standards, it wouldn't even count as a settlement—just widened tunnels, reinforced chambers, and old stone rooms carved by hands that hadn't expected to live long. But by underground standards, it was stable.
It had water that usually flowed.
Food that usually grew.
Light that usually stayed on.
That made it worth staying in.
Luke turned into a side cavern where the ceiling dipped low enough that taller adults had to stoop. Heat washed over him as he stepped inside. This was the workshop.
Metal rang against stone. A hand-cranked lathe whined softly. Someone swore when a tool slipped and bit skin.
At the center of the cavern sat Old Garron.
He was hunched over a bench, one eye squinted shut, the other peering through a cracked lens at a strip of metal. His beard was white and uneven, his hair thin enough that the lamp glow reflected off his scalp. His hands, though, were steady—steady in the way that only came from repetition and consequences.
Luke set the crate down beside the bench, lowering it carefully instead of letting it drop.
"Surface scrap?" Garron asked without looking up.
"Yes," Luke said. "Trade caravan brought it in this morning."
Garron grunted. "Smells like surface."
Luke almost smiled.
Surface scrap always did. It carried damage that underground metal never learned to fear—weather corrosion, unstable mana exposure, violent impacts from things that didn't care how humans built. The stress patterns were different. The failures told longer stories.
Luke reached into the crate and lifted a cracked casing.
This one felt wrong.
Too precise for underground work. Too delicate for Alerian forging. The seams were clean. The edges were smooth. Whatever it had once contained hadn't been meant for hands and guesswork.
"Careful with that," Garron said suddenly, finally glancing up. "That piece bites."
Luke paused.
"I know," he said.
He didn't know how he knew. But his fingers had already wanted to pull back, the same way skin reacted to heat before pain arrived.
Garron studied him for a moment. "You feel it again?"
Luke hesitated, then nodded. "Yes."
"Hmph." Garron leaned back. "You always do."
Luke had done it since he was small—flinching from supports before they cracked, refusing tools that later snapped, avoiding water lines that ended up contaminated. At first people called him careful.
Then they called him lucky.
Garron never used either word.
"Sit," the old man said, pushing a stool toward him. "Tell me what you think it was."
Luke sat and turned the casing slowly in his hands. His eyes unfocused—not drifting, just assembling shapes and pressures in his head.
"Power housing," he said after a moment. "Not pure mana."
Garron leaned closer. "Explain."
"The channels are too narrow," Luke said, tracing a groove. "Mana would clog them. Whatever ran through this needed regulation. It followed a fixed, almost robotic pattern."
Garron let out a dry laugh. "You talk like a surface mechanic."
Luke flushed. "You said—"
"I know what I said," Garron cut in. "And I stand by it. You see how things behave when no one's touching them."
He took the casing and turned it slowly. "How many towns have you seen fail, boy?"
Luke blinked. "I haven't."
"I have," Garron said quietly. "Enough to know that clever people don't die first. Loud ones do."
A low rumble rolled through the stone. Lamps trembled, flickered once, then steadied.
No one panicked.
"Monster movement?" Luke asked.
"Maybe," Garron replied. "South tunnels. We'll hear if it matters."
Luke nodded, storing it away like everything else.
"Can I take this home?" he asked, lifting the casing.
Garron eyed him. "Planning to break it?"
"Not yet."
The old man snorted. "Good. Stare at it until you hate it. If you still want to cut after that, you're ready."
Luke nodded.
As he turned to leave, Garron spoke again. "And Luke."
"Yes?"
"Whatever it is you notice—keep it quiet. People like help they don't have to thank."
Luke swallowed. "I understand."
Luke's home was small.
Two stone chambers separated by a hanging cloth. A cooking pit in one corner. Sleeping mats stacked neatly. Tools hung on pegs in careful order. Disorder wasted time, and wasted time got people hungry.
His father, Eren, sat near the pit, repairing a leather strap with slow, practiced stitches. Broad shoulders. Scarred hands. A faded tattoo on his forearm—pathfinder work, long past its prime.
"You're late," Eren said.
"Workshop," Luke replied.
Eren nodded once. "You eat yet?"
"Later."
From behind the cloth, Luke's sister Mira leaned out. "Did you bring something interesting?"
Luke hesitated, then showed her the casing.
Her eyes widened. "Surface?"
"Yes."
"Does it work?"
"Not anymore."
"Then it's boring," she said, vanishing again.
Luke smiled faintly.
He knelt beside his mat and set the casing down. He didn't open it. He just looked.
He imagined how it had once moved, how power had flowed through it in a rigid, repeatable way. How it must have failed the same way every time until it broke.
A faint warmth brushed his shoulder beneath his tunic—nothing active, nothing demanding. Just present.
Luke ignored it.
*"…For now, he was just a human in an underground town, studying something broken, trying to understand why it had stopped working.
That was enough.".*