Our Narrow Sky

Chapter 1: The Hull

The ocean tried to kill you slowly, and Georgia Muller respected that.

She floated thirty meters off the colony's western arc, suspended in water so dark it might as well have been ink, her helmet lamp cutting a pale cone through the black. The Depth sprawled below and around her—a vast lattice of interconnected modules, domes, and corridors clinging to the Pacific seabed like a barnacle city. Lights glowed from hundreds of portholes, amber and blue, the only warmth in a world that held steady at two degrees Celsius.

Her suit's heads-up display painted the hull section in green wireframe overlay. Section W-17. Micro-fracture reported by the internal pressure sensors twelve hours ago. Routine.

Everything down here was routine until it wasn't.

"Georgia, you're drifting north," said the voice in her earpiece. That was Petros Vahn, her dive supervisor, monitoring from the operations bay inside the colony. He had a calm voice, the kind that belonged to someone who'd spent twenty years talking people through emergencies and had learned that panic was contagious.

"Correcting." She thumbed the left thruster on her wrist mount and felt the gentle push realign her trajectory. The hull section grew in her lamp's beam—riveted panels of composite alloy, each one roughly three meters square, bolted to the colony's skeletal frame. She could see the discoloration where mineral deposits had begun to crust along the seams. That was normal. The ocean was always trying to reclaim what humans had built.

She reached the panel and pressed her gloved palm flat against it. Through the haptic sensors in her suit, she could feel the faintest vibration—the colony breathing, its air recyclers and water pumps and hydrothermal converters all thrumming in concert. Eight thousand heartbeats on the other side of this metal.

"Visual on W-17," she reported. "Starting scan."

She unclipped the portable sonar unit from her belt and held it against the panel. The device hummed, sending pulses through the alloy, mapping its internal structure in cross-section on her display. There—a hairline fracture, barely two millimeters wide, running diagonally across the panel's lower quadrant. No active leak yet, but at this depth, two millimeters was a conversation the ocean was having with itself about when to come inside.

"Confirmed micro-fracture, lower quadrant, two-point-one millimeters. No breach. Recommending sealant and a monitor tag."

"Copy that. Proceed with repair."

Georgia pulled the sealant applicator from her tool harness. The compound was a polymer that bonded with the alloy at molecular level—one of the Depth's genuinely impressive innovations. She'd heard the chemists in Module 6 had spent three years developing it. She traced the fracture line carefully, laying down a thin bead of sealant that glowed faintly blue before hardening to match the hull's gray.

This was her world. The dark water, the metal skin of the colony, the quiet voice in her ear. She'd been diving since she was nineteen—eleven years now—and she knew the Depth's exterior better than most people knew their own apartments. Every weld, every patch, every place where the structure had been reinforced or extended. The colony had grown over the decades, module by module, and its hull told the story of that growth in layers of repair and modification.

She finished the sealant line and pressed a monitor tag into place—a small adhesive sensor that would track the fracture's status and transmit data back to operations. If it widened, they'd know within minutes.

"W-17 sealed and tagged. Moving to next assignment."

"Next is W-22. About forty meters southeast of your position. Another micro-fracture, same pressure ring."

"On my way."

She pushed off from the hull and let herself drift for a moment, orienting by the colony's lights below. From out here, the Depth looked almost beautiful—a constellation of warm points in the abyss, connected by the faint lines of illuminated corridors. It was easy to forget, floating in the silence, that this fragile web of metal and light was all that stood between eight thousand people and oblivion.

Or so they'd been told.

Georgia didn't dwell on philosophy during dives. Philosophy was for the rec halls and the hydroponic gardens, for people who had time to sit and think about the surface they'd never see. She had a hull to maintain. She thumbed her thruster and began moving southeast.

The swim took her along the colony's upper curve, past the agricultural domes where banks of grow-lights cast green-tinged halos into the water, past the children's education module with its brightly painted exterior—a cheerful gesture that only the divers ever saw—and toward the older sections of the colony where the original construction was heaviest.

W-22 was in what the dive team called the Spine—the central structural beam that ran the length of the Depth like a backbone. It was the oldest part of the colony, the first piece sunk to the seabed when the Depth was established. The metal here was thicker, heavier, and showed its age in patterns of corrosion that the maintenance teams fought a constant battle against.

She was approaching the panel when her lamp caught something.

A line. Vertical. Running from the colony's upper structure straight up into the darkness above.

Georgia stopped her forward motion and hung in the water, staring. Her lamp couldn't reach far enough to follow the line to its terminus—it vanished into the black maybe fifteen meters above her—but what she could see was enough to make her pulse quicken.

It was a cable. Steel, by the look of it, about three centimeters in diameter, braided in a pattern she recognized from heavy-duty industrial rigging. It was anchored to a mounting bracket on the Spine's upper surface—a bracket she'd never noticed before, though she'd swum this section dozens of times. The bracket looked purpose-built, welded directly into the structural beam, and the cable rising from it was taut. Not slack, not drifting in the current. Taut. Pulled tight by something above.

Something above.

There was nothing above. Above was the ocean, five hundred meters of crushing water, and above that was the surface—the dead surface, scoured by radiation since the magnetosphere collapsed thirty-two years ago. There was nothing up there to anchor a cable to.

"Petros," she said. Her voice was steady. She was proud of that. "I'm seeing something unusual at the Spine. Upper structure, near W-22."

"Define unusual."

"A cable. Steel braided cable, approximately three centimeters, running vertical from a mounting bracket on the Spine. It's under tension. Goes up beyond my visual range."

Silence on the line. Not the comfortable silence of a supervisor checking instruments. The heavy silence of someone choosing their next words carefully.

"Can you describe the mounting bracket?"

"Welded directly to the beam. Looks integrated—not improvised. Petros, this isn't salvage or debris. This is manufactured infrastructure."

More silence. Then: "Georgia, proceed to W-22 and complete your repair. I'll flag your observation for engineering review."

"Petros—"

"Complete your repair, Georgia. We'll discuss it when you're back inside."

She wanted to argue. She wanted to swim up along that cable and follow it into the dark until she found whatever it was anchored to. But she was a professional, and she was on a pressurized dive with a finite air supply, and Petros was right that the fracture at W-22 was the priority.

She repaired the fracture. She tagged it. She did her job.

But she kept glancing up into the darkness where the cable disappeared, and she felt something she hadn't felt in a long time.

Uncertainty.

---

The decompression chamber was a steel cylinder barely wide enough for two people, lined with benches and equipped with the controlled atmosphere system that slowly brought a diver's body back to colony-normal pressure. Georgia sat in her undersuit, her dive gear racked on the wall beside her, and breathed the warm, slightly metallic air while the chamber hissed and equalized around her.

Normally she used decompression time to sleep or read. Today she sat with her hands on her knees and stared at the wall and thought about cables.

The Depth's official history was straightforward. Thirty-two years ago, Earth's magnetosphere had undergone a catastrophic collapse—a geophysical event that scientists had warned about for decades but that had arrived faster and more completely than anyone predicted. Without the magnetic field to deflect solar radiation, the surface became uninhabitable within months. Oceans, however, provided natural shielding. The Depth had been constructed as an emergency refuge, one of several deep-sea colonies established by a consortium of governments in the final years before the collapse. Eight thousand people had been selected—engineers, doctors, farmers, teachers, the essential cross-section of humanity needed to sustain a civilization underwater.

That was the story. Georgia had grown up with it. She'd been born in the Depth, as had most people under thirty. The surface was a memory held by the elders, a place of photographs and stories, of blue skies and open air that the younger generations would never experience. It was history. It was settled.

A steel cable under tension, running toward a surface that was supposed to be dead, was not settled.

The decompression cycle completed with a soft chime, and the inner hatch unsealed. Georgia pulled on her colony jumpsuit—standard-issue gray with her dive team patch on the shoulder—and stepped into the corridor.

The Depth's interior corridors were functional rather than beautiful. Metal walls, rubberized flooring, LED strips along the ceiling that cycled through a simulated day-night pattern. The air smelled of recycled humidity and the faint mineral tang that was the signature of water processed through hydrothermal filters. People moved through the corridors in the unhurried way of a population that had nowhere else to go—technicians in work coveralls, children in school groups, a pair of growers carrying trays of lettuce from the agricultural dome.

Georgia headed for Operations.

The operations bay was in Module 1, the administrative heart of the colony. It was a large room filled with monitoring stations, each one tracking a different aspect of the Depth's life support—pressure, atmosphere, power output, water quality, structural integrity. Petros Vahn was at the dive coordination station, a stocky man in his fifties with close-cropped gray hair and the permanently squinted expression of someone who spent too much time staring at screens.

He looked up when she entered. His face was carefully neutral.

"Good repair work out there," he said. "Both fractures sealed clean."

"Thanks. About the cable—"

"I've flagged it. Engineering will review."

"Petros." She pulled a chair over and sat facing him. "That cable is under tension. Something is pulling on it from above. What's up there?"

"Could be debris. Old anchor line from the construction phase. There's a lot of legacy infrastructure on the exterior that never got cataloged properly."

"An anchor line wouldn't be taut after thirty years. The currents would have corroded the anchor point or snapped the cable. And the mounting bracket was clean—no significant corrosion. That bracket is being maintained."

Petros's jaw tightened almost imperceptibly. "I've flagged it, Georgia. That's the process. You report, I flag, engineering reviews. That's how it works."

"How long for the review?"

"However long it takes. You know how the queue works."

She did know. Engineering review requests could sit in the queue for weeks. The Depth had a thousand maintenance priorities at any given time, and a mysterious cable that wasn't actively threatening hull integrity would rank low.

"I want to go back out and follow it," she said.

"No."

"Petros—"

"Your next dive rotation is in forty-eight hours. Standard assignment. You don't freelance on dives, Georgia. You know that."

She knew that too. Solo exploration dives were forbidden—too dangerous, too resource-intensive. Every dive was scheduled, approved, and monitored. The rules existed for good reason. But the rules also assumed that there was nothing unexpected to find.

"Fine," she said. "Forty-eight hours."

She left Operations and walked the corridor toward her quarters, her mind turning the cable over and over like a stone in her hand.

---

Her quarters were in Residential Block C—a small room with a bunk, a fold-down desk, a narrow closet, and a porthole that looked out into the dark water. The porthole was her luxury. Most residential rooms were interior, windowless. Divers got exterior rooms as a perk of the job, a small compensation for the risk they took every time they went outside.

She sat on her bunk and pulled up the colony's public database on her wall-mounted terminal. The database was the Depth's collective memory—technical manuals, historical records, educational materials, everything the population needed to understand their world and maintain it.

She searched for construction schematics of the Spine.

The results were sparse. The original construction documents were classified as "archival" and required administrative clearance to access. What was available publicly was a simplified structural diagram showing the Spine's general dimensions and the location of major systems—power conduits, water mains, atmospheric ducting. No mention of external cable mounts. No mention of any vertical infrastructure connecting the colony to anything above it.

She searched for "surface cable" and got nothing. "Cargo system" returned results about the internal logistics network—the small rail carts that moved supplies between modules. "External infrastructure" gave her the hull maintenance manual she'd memorized years ago.

Nothing about cables. Nothing about anything going up.

Georgia lay back on her bunk and stared at the ceiling. The LED strips were dimming toward their evening cycle, casting the room in warm amber. Through the porthole, the water was absolute black.

She'd been born here. She'd grown up believing the same story everyone believed—that the surface was gone, that the ocean was their shield, that the Depth was humanity's last refuge. She'd never had reason to question it. The colony functioned. People lived, worked, raised children, grew old. It was a constrained life, but it was life.

But a cable under tension meant something was on the other end. And if something was on the other end, then the surface wasn't what they'd been told.

Or she was wrong, and it was old debris, and she was building a conspiracy out of a piece of metal.

She closed her eyes and tried to sleep.

She couldn't.