An agonizing pain stung every inch of Zulfa’s body as his consciousness slowly drifted back. The air around him felt searingly hot, humid, and thick with the piercing stench of sulfur and burning oil.

Zulfa blinked his heavy eyelids. His vision was blurry, swimming with wild flashes of red and blue light. He tried moving his fingers, then his arms, until finally his entire body. Thankfully, no bones were broken, though the skin on his elbows and knees stung from sharp rock scrapes during his fall.

"Ugh... damn it," Zulfa wheezed hoarsely, clutching his throbbing head. He pushed himself up slowly, leaning against a large, fractured concrete block.

As his eyes adjusted to the surrounding darkness and neon glow, Zulfa’s breath caught in his throat. The sight before him wasn't the dust-choked bottom of a collapsed crater, but an entirely different world hidden deep within the earth’s belly—a colossal underground cavern whose scale surpassed human imagination.

"Good god... what is this place?" Zulfa whispered, awestruck and horrified all at once.

He stood inside the true "Apostle Arteries" of the earth. The chamber was immense, resembling an ancient cathedral forcefully fused with high-level modern machinery. All around him, massive steel pipes as wide as a house stretched vertically and horizontally, pulsing constantly like the living veins of a beast carrying glowing blue-purple liquid energy. Natural stone cave walls blended with rigid metallic structures, emitting a low-frequency harmonic hum that rattled his chest.

"Zulfa! Zulfa, can you hear me?!"

An anxious voice pierced the roar of the machinery from high above the cavern ceiling.

Zulfa snapped his head up in surprise. At the edge of a concrete ledge ten meters above him, the silhouette of a short-haired girl waved frantically.

"Naya?!" Zulfa cried out, half-in-disbelief. "How did you get down here?!"

"I wasn't about to let you die alone in this black hole, you stubborn engineer!" Naya called back from above, her voice clear despite being slightly muffled by the engine noise.

Naya didn't waste a second. With practiced agility, she clipped a portable rock-climbing safety rope—which she happened to carry in her field backpack—onto a sturdy iron pillar at the ledge's edge. Rigging a makeshift emergency pulley, she rappelled down swiftly, landing smoothly right beside Zulfa.

The moment her boots hit the ground, Naya dropped to her knees to check Zulfa over. "Are you badly hurt? Anything broken?" she asked anxiously, staring at a small cut bleeding on Zulfa's forehead.

Zulfa shook his head gently, wiping the blood from his temple as Naya helped him stand. "I'm fine, just bruised and a bit dizzy. But... how did you manage to follow me down here so fast, Naya? This place is hundreds of meters underground!"

Naya offered a thin smile, though her breath still came in ragged gasps from the adrenaline. "I saw you fall, and I knew my climbing rope was the only way to follow. Good thing my college rock-climbing instincts paid off." Naya swept her gaze around the chamber, her eyes widening in wonder. "And... wow. So this is the inside of the Ley-Line Arteries?"

"Yeah," Zulfa answered grimly, staring at the landscape of colossal machinery before them. "We're directly beneath the city's heart."

Walking slowly along a metal catwalk suspended above a rushing stream of blue liquid energy, they began to grasp the sheer scale of the illegal operation unfolding here.

At the end of the catwalk, they were greeted by a sight that made their blood boil. A gargantuan mechanical drilling rig the size of a multi-story building stood anchored in the center of the subterranean hall, plunging its massive drill bit directly into a cave wall pulsing with swirling vortexes of pure Ley-Line energy.

The drill roared loudly, siphoning brilliant blue raw energy from the earth's core and routing it through massive glass tubes into an automated refinement engine. At the output of the refinery, that pure energy was compressed and cast into gleaming, pitch-black crystal ingots—illicit energy commodities neatly packed into industrial containers stamped with the Aethel Corp logo.

"Good lord..." Naya muttered, her voice trembling as she covered her mouth with one hand. "They're not just opening dimensional rifts... they're turning Ley-Line energy into a massive commercial strip-mine to enrich the corporation."

"No wonder they didn't care if the city fell apart," Zulfa said coldly, clenching his fists until his knuckles turned paper-white with surging rage. "To them, human lives and the stability of the earth are just cheap operating expenses."

Suddenly, the sound of slow, elegant applause echoed through the vast machinery hall.

Clap... clap... clap...

Zulfa and Naya snapped their heads around in alarm toward the source of the sound.

From atop an upper-level iron catwalk spanning above the drilling rig, a young man dressed impeccably in a designer light-gray suit stepped down the steel stairs at a leisurely pace. He wore thin-rimmed glasses, his hair was combed back immaculately, and pinned to his lapel was a gold serpent-motif pin—an absolute badge of supreme corporate authority in this facility.

"Magnificent. Truly magnificent," the young man praised in a tone that was calm, relaxed, yet dripping with cold sarcasm. He paused on the bottom step, looking down at Zulfa and Naya from a distance of several meters.

"A mid-level municipal civil engineer and a discarded archive intern managed to bypass our military defense grid and land straight in the main engine room. I must admit, your persistence deserves some appreciation... Engineer Arditama."

Zulfa narrowed his eyes, glaring at the man before him. "Malik... or whatever your name is among the board of directors. You've turned this city into a mass grave!"

The man smiled faintly, neatly adjusting his suit cuffs. "A mass grave? Oh, no, Engineer. Such dramatic words for the evolution of civilization. What you see here is the future of humanity. This Ley-Line energy has sat buried uselessly underground for thousands of years without anyone utilizing it. We're simply helping the earth... 'share' its wealth with us."

"At the cost of thousands of civilian lives and turning this city into prey for extradimensional entities?!" Naya shouted furiously, unable to contain her outrage any longer.

The sharply dressed man glanced briefly at Naya, then let out a dry, dismissive chuckle. "Young lady, in every great leap forward, there are sacrifices that must be cast into the foundations. Weren't the ancestors of the Arditama bloodline the ones who did precisely that in the past, using forced laborers as sacrificial seals?"

Zulfa froze for a second, but his gaze sharpened into a razor's edge. "My ancestors did that to hold monsters back, not to merchandise the destruction of the world like you are!"

The man let out a long sigh, slipping both hands into his trouser pockets. The smile on his face vanished entirely, replaced by a merciless, freezing expression.

"Too bad you know far too much, and your mechanical cleverness won't save you from this place," the man said quietly. He raised one hand, gesturing a command toward the shadows behind the iron bridge. "Secure them both. If they fight back, just toss their remains straight into the black crystal refinery."

Click! Click!

From behind the shadows of the massive machinery pillars surrounding them, a dozen heavily armed private security guards wearing tactical masks emerged in unison, leveling their rifle barrels straight at Zulfa and Naya, sealing off every possible escape route.