The echo of dripping water carried through the tunnel like the slow ticking of a clock. Lin's breathing was steady, though his pulse was anything but. The cold, damp air pressed against his skin, mingling with the stale reek of mold and rust. Every footstep seemed too loud, even when he tried to keep his weight light, careful. Behind him, Keller's boots scuffed against the wet concrete, while Min-joon's flashlight beam cut nervously through the shadows.

"Keep it down," Lin whispered, his voice no louder than the soft scrape of a rat darting along the tunnel wall. "Sound carries here. More than you think."

Min-joon clicked off the flashlight at once, plunging them into thick darkness. Only the faint glow of distant maintenance lamps, hanging weak and yellow, gave any shape to the corridor ahead.

"They're close, aren't they?" Keller muttered. He didn't need an answer; the tension in the air was already thick with the knowledge.

Lin pressed his back to the wall, tilting his head just slightly. From the far end of the tunnel came a faint hum — not mechanical, not water — but voices. Distant, muffled, moving. A patrol, maybe. Or worse, hunters.

"They knew we'd take this route," Lin murmured. His jaw clenched. "Jin's got eyes in every crack of this city."

Min-joon swore softly under his breath. "How the hell are we supposed to move if every exit is waiting for us?"

Keller gave a low grunt. "We don't run for the exits. We make our own."

The words hung in the air like a spark waiting for flame. Lin didn't immediately answer; he was listening again, gauging the movements of their unseen pursuers. Then, with a sharp flick of his wrist, he signaled them forward.

The three moved quickly now, steps in rhythm, bodies low. The tunnel widened into an old junction where pipes snarled across the ceiling like veins. Rust streaked down the concrete walls, and pools of stagnant water reflected their dim outlines. It was a place forgotten by most of Seoul, a piece of its underbelly long abandoned to rot — yet perfect for those who wanted to hunt in shadows.

Lin crouched, motioning Keller and Min-joon to halt. His eyes scanned the branching corridors: three ways forward, all swallowing into darkness. He ran his fingers across a spray-painted mark on the wall — old, barely visible, a symbol used by smugglers long before Jin's rise. A reminder that others had walked these same paths.

"They're herding us," Lin said quietly. "If we choose wrong, we walk into a choke point."

"Then how do we know what's right?" Keller asked.

Lin didn't answer with words. Instead, he bent low, his fingertips brushing the ground. Damp footprints — faint, fresh, leading toward the left corridor. He traced the edge of one with a frown. The boot tread wasn't theirs. Too wide. Too heavy.

"They've been through here," Lin said, standing. "Left is a trap."

"Middle then?" Min-joon asked, nerves sharpening his voice.

Lin's eyes flicked toward the center tunnel. The air that drifted from it was colder, sharper, carrying the faint metallic tang of iron and salt. Underground runoff, maybe leading closer to the Han River. Dangerous, but it gave them distance.

"Middle," Lin confirmed.

They moved again, faster now, feet splashing silently through shallow puddles. The tunnel narrowed, pressing the three of them closer together, walls closing in like the throat of some beast. Lin's hand stayed near the grip of his pistol, though he prayed it wouldn't come to that. Gunfire here would echo for miles, drawing every predator in the maze.

A noise shattered the silence — a clang of metal against concrete, too deliberate to be accident. Keller spun, weapon half-raised, but Lin caught his arm.

"They want you to shoot," Lin said through gritted teeth. "Don't give them what they want."

Another sound followed — a whistle, faint but piercing, bouncing off the tunnel walls. It was a signal.

Min-joon's eyes widened. "They're closing in."

"Yes," Lin said, scanning the ceiling above. "But not fast enough."

He spotted it — a maintenance ladder leading upward into a rusted hatch. Without hesitation, he leapt forward, gripping the cold rungs. "Up!" he barked.

Keller didn't argue. He gave Min-joon a shove toward the ladder before covering their rear, pistol drawn but angled low. Min-joon scrambled upward, the ladder creaking under his weight. Lin was already pushing the hatch above with his shoulder. It groaned, reluctant to move, rust locking it in place.

Below, the whistle echoed again, closer now. The hunters were coming.

"Move it, Lin!" Keller hissed.

Lin braced, shoving hard. With a screech of torn metal, the hatch finally gave way, revealing a gap into pitch darkness above. He hauled himself up, pulling Min-joon through, then turned to reach down for Keller.

The sound came before the sight — boots pounding, splashes of water. Shadows lunged into view at the far end of the tunnel. Dark figures, hooded, masked, weapons glinting under the faint yellow lamps. Jin's hunters.

"Keller, now!" Lin snapped.

Keller didn't need more urging. He sprang up the ladder, Lin grabbing his arm and hauling him through just as the first shot cracked through the tunnel. The bullet sparked against the ladder's side, ricocheting into the darkness.

Lin slammed the hatch shut, plunging them into near-silence above. Only their ragged breathing filled the air.

They were in another chamber — wider, older. The stale scent of oil and dust clung to the walls. Massive industrial fans, long dead, loomed like silent sentinels. Pipes twisted through the ceiling, dripping condensation into pools on the floor.

"This isn't better," Min-joon whispered. "It's worse."

"No," Lin said, eyes adjusting to the dimness. "It's survival. They'll search every tunnel down there. But this level? Forgotten. We bought time."

Keller checked his pistol, the faint click echoing. "Time for what?"

Lin's gaze swept the chamber, mapping every exit, every shadow. His mind was racing, drawing lines between Jin's reach, the city's underbelly, and the files Sang-ho had left behind. Every step forward seemed to tighten the noose. Yet forward was the only path.

"For us to find the ghost before they find us," Lin said finally.

A silence followed, heavy with the weight of what lay ahead.

Then, faintly, from below the sealed hatch, the whistle echoed again — shrill, hungry, promising they weren't done yet.

And Lin knew: Seoul's depths had become their battlefield.