The descent capsule gave a violent shudder as it broke the surface, dropping from the airy noise of the harbor into the sudden, crushing silence of the sea. A dull thoom reverberated through the walls, a sound so low it was felt more than heard—the sound of a ton of water displacing. It was followed immediately by the sharp, automated hiss of pressure seals locking in place. Gurgling foam and white water surged past the thick viewport, and then, just as quickly, the world beyond turned a deep, suffocating blue.
Vorren steadied himself, his hand flat against the cold metal bulkhead. The capsule tilted slightly, a controlled drop as it locked onto the magnetic guide rail. The low hum of the turbines filled the confined chamber, a steady vibration he could feel in the soles of his boots. The air already tasted metallic, recycled and scrubbed. Lights along the interior flickered in a steady rhythm, pulsing in time with the descent shaft's external guide-lights—a tunnel of reinforced glass and alloy that spiraled into the deep.
Aethros crouched low beside him, a mass of coiled muscle and black fur. His amber eyes, glowing faintly in the dim light, scanned every joint and seal in the cabin.
"This thing feels too fragile," the beast muttered, his voice a low rumble. "A single hairline fracture in that viewport, one faulty seal..."
"Don't," Vorren said quietly. His own gaze was fixed on the viewport, where the pressure was already visibly compressing the water into a darker, denser teal. "This capsule is rated for three thousand meters. We're only going to fifteen hundred. Let's not test the theory."
Outside, the last shimmering, distorted glimmer of sunlight faded. It wasn't a gradual sunset; it was an abrupt snuffing of a candle. They were leaving the world of air and sky behind, plunging into a realm that had never known the sun.
Darkness pressed in, absolute and total, a void that seemed to soak up the capsule's internal light. But it lasted only a moment. It was soon replaced by something else—light.
Thousands of luminescent threads, pale green and electric blue, glowed faintly along the descent shaft's outer walls. They weren't part of the structure; they were living things, clinging to the alloy. The deeper the capsule sank, the brighter this cold, biological light became. It illuminated ghostly shapes in the passing water—vast, spectral schools of fish darting through the water like showers of silver needles, entire forests of colossal kelp swaying with bioluminescent leaves, and farther out, in the deep black, colossal silhouettes moving. They were too large and slow to be whales, their forms indistinct and ancient.
Aethros' ears twitched, swiveling to track a sound Vorren couldn't hear. "There's life down here. Something... big."
Vorren nodded, his eyes tracking one of the distant shadows. "And it's watching us."
The capsule continued to sink, faster now, a smooth, silent fall. The pressure gauge on the console ticked steadily higher—500 meters... 800... 1,200. At 1,500 meters, the ocean thickened into something almost tangible, a pressurized gel that seemed to fight the capsule's passage. The vessel's structure, which had been humming, now began to creak. Small, sharp pings and groans of metal under stress echoed in the cabin. Small currents rippled against the glass, no longer silent, whispering against the hull like distant, sibilant voices.
Then, as if a curtain had been torn away, the darkness split apart.
Nereis City emerged from the abyss like a dream of glass and steel.
It was a city of impossible light. Vast domes of transparent alloy, each one kilometers wide, dotted the seabed. They were connected by a sprawling network of winding, pressurized tubes that glowed with a soft, cerulean light, like the circulatory system of a god. Each dome pulsed faintly, a slow, steady heartbeat as it cycled its atmosphere, breathing life into its enclosed ecosystems. Through the reinforced alloy, Vorren could see them: entire forests of towering, pale trees, artificial rivers carving canyons through landscaped rock, and glowing coral reefs thriving beneath an impossible pressure.
At the city's center, a colossal spire rose from the ocean floor, an obsidian tower wrapped in rings of brilliant light that spiraled endlessly upward, disappearing into the blackness above. It was the city's anchor, its power source, and its central hub. Around it, fleets of submersibles and maintenance drones glided like shoals of silver fish, their searchlights cutting sharp, white beams through the dark water. The city was alive, a living organism built from metal and current.
Vorren leaned forward, his palm pressing against the viewport, the glass cold against his skin. He said nothing, his breath fogging the surface. "It's bigger than I imagined."
"It's unnatural," Aethros replied, his initial tension replaced by a predator's awe. "A fortress of light in a world that demands darkness. But it's beautiful."
The capsule slowed, the hum of its turbines changing pitch as it decelerated, aligning with a docking port on one of the outer domes. Automated docking clamps, massive and spider-like, extended from the station wall, locking the vessel into position with hydraulic precision. A brief, jarring hiss of displaced water followed, then a metallic chime echoed through the cabin.
Atmospheric equalization complete. Welcome to Nereis City.
The heavy inner doors slid open with a clean sigh of air.
They stepped out into a corridor bathed in cold, white light. The gravity felt different—not stronger, but heavier, denser. The air itself seemed to push back, tinged with the sharp smell of ozone, recycled salt, and filtered minerals. Every sound was muted, swallowed by the thick, high-pressure atmosphere. The slight ringing in Vorren's ears told him the pressure here was significantly higher than the surface standard.
A holographic attendant, a shimmering blue figure of a woman in a crisp uniform, flickered into existence before them. "Welcome, visitors. Please proceed to customs and registration. For your safety, all protocols must be followed. Unregistered travel between biodome zones is strictly prohibited."
The hologram dissolved. Vorren and Aethros exchanged a glance. "Let's just stay quiet and blend in," Vorren murmured, pulling the hood of his cloak slightly lower.
They followed the glowing arrows embedded in the polished floor, the corridor curving gently. They passed others in sleek, dark compression suits—engineers with data-slates, scientists arguing in low tones, and grim-faced mercenaries, their light body armor glinting over their suits. Everyone moved with a quiet, efficient purpose. Along the transparent walls of the corridor, Vorren caught glimpses of the outside world: massive, floodlit chains anchoring the domes to the seabed, articulated mechanical arms adjusting turbine lines, and creatures drifting past.
Some were graceful, shimmering collections of light. Others were monstrous.
One brushed lazily against the glass, its movement impossibly slow, like a drifting continent. The light from the corridor illuminated a vast, puckered landscape of pale flesh before revealing an enormous eye, easily two meters across, golden and ancient. Its pupil, a vertical black slit, swiveled slowly and seemed to focus on them, an intelligent, alien gaze.
Aethros' fur bristled, rising along his spine in a wave of primal aggression. "That thing could swallow this entire docking bay, not just a ship," his mental voice was a low snarl.
"Then let's hope it doesn't get hungry," Vorren replied under his breath, never breaking stride, forcing a casualness he didn't feel.
They reached the customs hall, a cavernous space filled with the quiet hum of scanning beams and the shuffle of orderly queues. The ceiling was a vault of metal, reinforcing the dome above. Translucent holographic banners displayed the primary rules in a dozen rotating languages.
No external weapons beyond Tier 2 authorization.No unregistered bioforms in habitat zones.Unauthorized exploration of the biodome perimeter is prohibited and will be met with lethal force.
Vorren adjusted his cloak, ensuring it was smooth. "Stay calm. You're licensed. Just follow my lead."
When they approached the registration console, a human clerk looked up. He was tired, his skin pale from the recycled air, but his eyes were sharp. "Name and purpose?"
"Vorren," he answered smoothly, sliding his ident-chip into the scanner. "Freelance research contractor. Short-term study on marine force currents for the hydro-engineering department."
The clerk raised a skeptical brow as his eyes flicked to Aethros. "And the hybrid?"
"Registered companion. Part of the study. Trained and temperament-controlled. His license is linked to my file."
The clerk stared for a long moment, his fingers hovering over his console. Finally, with a small sigh that spoke of bureaucratic exhaustion, he shrugged and tapped the console. "Two temporary residence permits. Tier One access. You'll be staying in the outer ring, sector Gamma, until your research credentials are fully reviewed. Room assignments are randomized daily for security. That'll be 120 Solars for the entry-processing fee."
Vorren transferred the funds without comment.
As he received the two small, metallic access chips, the overhead lights flickered. The quiet hum of the station was suddenly drowned out by a deep, resonant vibration that rippled up through the floor, rattling the consoles and shaking a nearby rack of equipment. Everyone in the room froze.
"What was that?" Aethros whispered, his body tensing.
A technician at a nearby console looked up, his face pale but practiced. "Pressure shift," he called out, his voice a little too loud. "Just the biodome expanding to regulate air density. Happens all the time."
Vorren glanced toward the reinforced glass wall that looked out into the black. For a split second, he thought he saw it—a shadow drifting beyond the station's floodlights, a shape so massive it blocked the distant lights of the central spire. It was slow, deliberate, and it was watching. Then it was gone, swallowed by the abyss.
They exited the station into a suspended walkway that overlooked the central dome they had entered. Below them stretched the biodome—a vast, enclosed world glowing in shades of vivid green and soft blue. He could see towering forests swaying beneath an artificial sun, a glowing orb suspended at the dome's apex. He could hear the faint, distant sound of running water and synthesized birdsong. Rivers flowed over submerged cliffs, and the faint outlines of creatures moved in the distant, cultivated jungle.
"This is where we'll train," Vorren murmured, more to himself than to Aethros.
Aethros' claws clicked softly against the metal floor. "It'll do."
Vorren took a slow breath. The air here tasted different, as the hologram had warned—clean, heavy, and dense with unseen force currents. He could feel it pressing at the edge of his perception, a tangible weight on his skin, like the ocean itself was testing him, feeling him out.
Somewhere below, in the shadow of the central spire, something shifted—an unseen rhythm that pulsed faintly through the station's structure, almost in tune with his own heartbeat.
He didn't know yet if it was the city itself… or something that lived beneath it.