The flaw was there. She could feel it.
Kael pressed her thumb along the curve of the lens and closed her eyes. The glass talked to her fingers the way water talks to a sailor's hull — in pressures too subtle for language, in truths that words would ruin. There. A ridge, thin as a hair, where the grind had wandered. She'd been at it since the third bell and the light through the workshop louvers had gone from white to amber and she hadn't eaten and didn't care. A lens either told the truth or it lied. There was no almost.
She dipped the grinding stone in wet sand and started again.
The workshop occupied the second floor of a tower that had once been something else — something from the Before, with walls of grey stone and steel bones showing through where the plaster had given up. Her grandfather had cleared the rubble. Her mother had installed the louvers. Kael had built the grinding table herself at sixteen, burning her left forearm on a crucible of molten glass in the process. The scar ran from wrist to elbow, shiny and tight. She never covered it. It was a record of learning, and she kept her records honest.
Outside the louvers, the city breathed. Sellers calling prices in the market three streets down. A hammer on an anvil, steady as a heartbeat. Children somewhere, fighting or playing — same sound at that age. The city-state of Tidemouth sat in the bones of something ancient, a port that had once connected to a world that no longer existed. The old towers rose along the harbor, gutted and repurposed, their original function lost to everyone but the glass-eyes — scholars who spent their lives reading texts they only half understood, squinting at faded diagrams in languages that had drifted beyond recognition.
Kael was a glass-eye. She ground lenses for money and studied the Before for love.
The lens under her hands was a commission for a merchant captain who wanted a spyglass that could read a flag at three leagues. Simple work. Profitable. Boring. She shaped the curve from memory, her hands doing what her hands knew while her mind did what her mind preferred: turning over the problem of the old observatory.
She'd found it six months ago. North of the city walls, past the salt flats where nothing grew, in the hills where the Before had built things so large they'd survived five centuries of weather and neglect. Most people avoided the ruins. Bad air, bad footing, bad luck according to Sekani's stories. Kael avoided superstition the way she avoided adverbs — ruthlessly, and with the conviction that both were signs of imprecise thinking.
The observatory ruins were different from the usual Before wreckage. Not a tower, not a road, not a wall. A vast bowl carved into a hillside, hundreds of paces across, lined with metal panels that had corroded to green lace. And beneath it, sealed rooms that still held air.
She finished the merchant's lens, held it to the fading light, and saw the world snap into perfect clarity through its curve. Good. She wrapped it in oiled cloth and set it by the door. Tomorrow she'd deliver it and collect her fee. Tonight she had other plans.
Tidemouth after dark was a different animal than Tidemouth by day. The market stalls shuttered and the cookfires lit and the arguments moved from commerce to philosophy, which in Tidemouth meant the same thing with more hand-waving. Kael walked the long way to the harbor, taking the Street of Makers where the metalworkers banked their forges and the weavers hung their last bolts to air. A funeral procession passed her going the other direction — torches, wailing, a body wrapped in sail-cloth carried on the shoulders of four women who looked too angry to be sad. Someone had died young. The mourners didn't walk in order. They stumbled, clutched each other, broke formation and reformed. A child ran alongside, not understanding, holding a flower that was already wilting.
Kael stopped and bowed her head. Not prayer — respect. In Tidemouth, you let the dead pass. Then you kept walking, because the living still had work to do.
She passed the harbor. Moss was there — she could see his silhouette on the dock, bent over a hull he'd been caulking for three days. Broad shoulders, crooked nose, the particular way he held his weight like a man always braced for a wave. She thought about stopping. She didn't. She had somewhere to be and if she stopped to talk to Moss she'd lose an hour to his stories and his questions and that way he had of looking at her like she was a horizon he was trying to read.
At the north gate, Old Sekani sat on his stool where he always sat, wrapped in a blanket despite the heat, watching the road with eyes that had seen eight decades and believed every one of them had been a gift.
"Glass-eye," he called. "Where do you go when the sun goes down?"
"Nowhere useful," she said.
"Liar. You're going to the ruins again."
She stopped. "How do you know that?"
Sekani smiled. His teeth were mostly gone. His smile was mostly wonderful. "Because you have that look. The one your mother had when she was working on something she couldn't talk about yet. The look that says: I see something, and I'm not sure what it is, and I won't rest until I am."
Kael almost smiled. "It's just old metal, Sekani."
"Nothing is just anything." He leaned forward. "You know what the Before people built up there? A listening machine. A great ear, pointed at the sky. They built it because they thought someone was talking and they wanted to hear."
"Who was talking?"
"Nobody, as it turned out. The sky was empty. But they built the ear anyway, because the act of listening was its own kind of faith." He settled back. "Go listen, glass-eye. Maybe the sky isn't empty anymore."
She left him there. His stories were beautiful and wrong and she treasured them and didn't believe a word.
The ruins were two hours' walk north, up a trail that the scrub had been eating for centuries. The hills here were dotted with Before debris — concrete foundations, rusted pipes, the occasional intact wall standing alone like a sentence without a paragraph. The old observatory sat in a natural depression between two ridges, the great bowl tilted slightly southward, its metal lattice mostly collapsed but the shape still readable against the stars.
Kael had mapped every accessible section over six months of night visits. The surface structures were gutted — weather, scavengers, time. But the underground levels had been sealed. Whoever built this place had anticipated that the surface wouldn't last. They'd put the important things below.
She descended through a crack in the foundation that she'd widened with a pry bar on her third visit. The tunnel angled down, concrete walls streaked with mineral deposits, the air cool and stale and somehow electric — a faint tang that made her think of lightning. Her lantern threw sharp shadows ahead. The tunnel opened into a corridor with doors on both sides. Most she'd already explored: storage rooms, a collapsed kitchen, something that might have been a dormitory. But the door at the far end — the heaviest door, set in a steel frame that hadn't corroded because it was made of something she'd never seen before — that door she'd only opened last week.
She pushed it now and felt the seal break with a soft exhalation, as if the room had been holding its breath.
Inside: racks of equipment. Metal boxes lined with components she couldn't identify — circuits, perhaps, though smaller and more intricate than anything the city's electricians built. Cables thick as her wrist running into the walls. And on the central table, connected to everything else by a spiderweb of wires: a rectangular assembly that she'd spent the last week studying.
It wasn't a lens. She knew lenses. It wasn't a clock or a compass or any instrument she recognized. But it was built with the precision of something that mattered — every component seated exactly, every connection deliberate. The craftsmanship spoke to her the way good glass spoke to her: this was made by someone who cared whether it worked.
She'd traced the cables. They ran upward, through channels in the walls, toward the great bowl above. The bowl wasn't a bowl. It was a dish. And this assembly wasn't a device.
It was a receiver.
Kael sat on the concrete floor and held a corroded circuit board in her lap. The components were green with oxidation but the layout was visible — traces etched in copper, chips soldered with a precision that made her grinding table look like a child's toy. She could strip the board. The copper alone was worth a week's income. The chips contained metals — gold, maybe, or something rarer — that the metalworkers would pay well for.
She turned the board over. On the back, someone had scratched a notation in faded ink. Numbers. A frequency, maybe, though the unit markers meant nothing to her. But the numbers were written in the same script as the old technical texts in the scholar-house library — the ones written in Technical Latin, the ones she'd spent years learning to half-read. Someone had calibrated this device. Someone had used it. Someone had pointed the great dish at the sky and listened.
Sekani's words came back: a listening machine.
The copper on this board was worth ten days of her income. The knowledge inside it might be worth nothing. It might be worth everything. She had no way to know without months of study, and months of study meant months of not making lenses, which meant months of not eating, which meant—
She put the board in her bag.
She'd figure out what it was. Even if it killed her, even if it was nothing, even if the sky was as empty as it had been for five hundred years. She would listen, because someone had built this place to listen, and abandoning it felt like a betrayal of a conversation she hadn't been invited to but couldn't walk away from.
Kael descended deeper into the sealed room, her lantern catching the dust motes that hung in air that hadn't moved in centuries. The receiver assembly sat on its table like a patient animal, waiting. She placed her hands on it, feeling the metal, cold and precise, and thought: What did you hear?
The room had no answer. But the dish above her, broken and tilted and blind, pointed south. Whatever this machine had been built to find, it had been looking toward the bottom of the world.