The night was ink?black,

  and the fog of steam and coal smoke

  reduced visibility in the Lower District to almost nothing.

  Which made it the perfect cover.

  Sunri, Ye Lingyun, and Amy

  moved like shadows

  through the tangled maze of pipes and abandoned structures.

  Amy knew this area intimately—

  she had grown up here.

  She led the two men around the lit patrol routes,

  past steam?valve stations still operating through the night,

  until they reached Valve Station No. 7.

  It was an old brick building long abandoned,

  its front gate chained shut,

  its windows shattered.

  But Amy circled to the back,

  and behind a pile of rusted scrap and debris,

  she found a hidden door

  almost indistinguishable from the wall.

  The hinges had clearly been maintained once—

  it opened with only the faintest scrape.

  Inside was a dust?choked control room,

  its consoles buried under grime.

  Amy walked straight to an old iron cabinet in the corner

  and shoved it aside—

  revealing a circular opening in the wall,

  about a meter wide,

  descending into darkness.

  “This is it,” she whispered,

  lighting a portable steam lantern.

  Its weak yellow glow illuminated the inner surface of the tunnel.

  Not rough stone—

  but something smooth,

  metallic,

  etched with impossibly fine, regular patterns.

  “This isn’t a steam pipe,”

  Sunri murmured, touching the wall.

  It was cold and unyielding.

  “I’ve never seen material like this.”

  “My brother said it’s part of the ‘old thing,’”

  Amy replied.

  “Older than the city.”

  Ye Lingyun ducked inside first,

  Azure Cloud Sword drawn,

  its tip angled forward.

  Sunri followed,

  carrying not only his pistol

  but also a weapon acquired in this world—

  a steam?driven long gun.

  The weapon was about a meter long,

  its body forged from sturdy metal,

  a small steam canister attached at the rear

  and connected to the chamber by narrow tubing.

  Pulling the trigger

  released compressed steam

  that propelled a specialized piercing round—

  far more powerful than ordinary firearms,

  though it required re?pressurizing after several shots.

  They had retrieved it earlier

  from a hidden cache near the ruins of Kyle Roan’s workshop.

  The tunnel was wider than expected,

  just enough for a person to walk while hunched.

  The air barely circulated,

  thick with the stale tang of old metal—

  but at least there was no deadly steam leakage.

  They descended steadily,

  the slope shifting from gentle to steep.

  The tunnel was unnervingly clean—

  no debris, no stagnant water—

  as if some unseen maintenance system

  still operated in silence.

  After half an hour,

  a faint glow appeared ahead.

  Not the lantern’s light—

  but a steady, pale blue radiance.

  They had reached the exit.

  The three of them peered out cautiously—

  and their breath caught.

  A vast underground expanse

  stretched beyond sight.

  Their tunnel opened high on a curved wall,

  like a small hollow in a cliff face.

  Below lay the foundation of the city—

  but not rock,

  not soil.

  A colossal structure,

  half?embedded in the earth,

  so massive it defied comprehension.

  Its form blended organic curves

  with geometric precision,

  its smooth silver?white surface

  still shimmering faintly

  despite untold ages.

  Countless glowing lines

  branched across it like veins or circuitry,

  all converging toward a central region

  pulsing with intense blue light.

  From that core,

  dozens of enormous “light conduits”

  extended upward,

  piercing the rock above

  and reaching toward the city overhead.

  Some conduits flickered erratically,

  their glow dim or broken,

  with arcs of unstable energy

  snapping at the ruptured ends.

  But what shocked them even more

  was the forest of steel structures

  built atop and around the ancient construct—

  boilers, gear assemblies, pistons, drive shafts,

  thick steam pipes.

  The entirety of steam civilization’s machinery

  had been grafted onto this ancient body

  like parasitic vines.

  Many pipes drilled directly

  into the glowing patterns,

  as if forcibly extracting something.

  This tale has been unlawfully lifted from Royal Road. If you spot it on Amazon, please report it.

  Two distinct sounds filled the cavern:

  the heavy clanging and hissing

  of steam machinery above,

  and beneath it,

  a deep, rhythmic hum

  from the ancient structure—

  like the heartbeat of a sleeping giant.

  “What… what is this?”

  Ye Lingyun’s voice was dry.

  The sight shattered everything he knew

  about mechanisms and engineering.

  “This is what lies beneath the power core,”

  Amy whispered, stunned.

  “My brother said the ‘old thing’ was down here,

  but I never imagined…”

  Sunri stared at the glowing conduits and patterns.

  The sun?mark on his palm

  throbbed with a warm, steady pulse,

  resonating faintly

  with the hum of the structure below.

  Lunelle’s gentle, resolute face

  flashed through his mind.

  “We’re going down,” he said.

  A series of steel maintenance platforms and ladders

  connected the tunnel mouth

  to the surface of the ancient construct—

  clearly built by later generations.

  They descended carefully.

  The closer they came,

  the heavier the pressure of the immense energy felt.

  Tiny motes of light drifted in the air,

  tingling faintly against their skin.

  Reaching a larger platform,

  they found several smooth silver?white panels

  embedded in the metal wall—

  completely out of place

  amid the steam?era machinery.

  Symbols and flowing patterns

  shifted across their surfaces,

  resembling the projections

  from the gemstone in the necklace.

  Sunri approached one panel.

  When his fingers brushed it by accident,

  the panel flared to life—

  symbols racing, rearranging—

  and then transforming

  into text and images they could understand.

  Fragmented records appeared:

  [Luminar Pulse Civilization — Final Log Fragment]

  “…Energy matrix overload irreversible.

  To prevent pulse?core detonation

  and extinction of all life forms,

  execute Final Protocol:

  descend into deep crust,

  enter dormant stabilization mode.

  May future intelligent beings

  learn from our failures

  instead of repeating them.”

  [Data Fragment: Pulse Core — Planetary Geothermal & Aether Converter]

  Description:

  This device is a multi?generational energy and ecological regulator,

  not a weapon.

  Excessive extraction of high?purity aether

  will cause spatial fractures,

  biological distortion,

  and destabilization of reality anchors…

  [Warning Log]

  Unauthorized external linkage detected…

  Energy siphoning in progress…

  Primary interface damaged…

  Stability falling to 67%… 58%…

  [Dark Age — Observational Notes (Speculative)]

  Civilization collapse.

  New species discover pulse core,

  unable to comprehend its nature.

  Reverence and fear coexist.

  Attempts made to imitate or seal it

  using primitive machinery (gears, levers)…

  [Mechanical Revival Era — First Contact Report (City Archives, Sealed)]

  “…Confirmed subterranean luminous megastructure

  as an infinite energy source.

  Initial steam?pipe linkage successful.

  Output exceeded projections by 3000%.

  Recommendation:

  establish strict secrecy and control.

  Energy properties unknown—extreme risk.

  Public explanation:

  ‘High?efficiency steam power core.’”

  [Imperial Year 47 — Incident Report A?7 (Top Secret)]

  Lower District pipe explosion.

  Actual cause:

  pulse?core instability leading to localized aether leakage.

  47 dead.

  Survivors exhibited hallucinations,

  physical mutations.

  Response:

  seal area,

  purge memories (physical),

  public explanation:

  ‘Boiler pressure?valve failure.’

  [Current Governor’s Directive (Highest Clearance)]

  All research into the true origin of energy

  or historical truth

  is treason.

  Any means may be used to eliminate leaks—

  including framing, disappearance, “accidents.”

  Maintain the narrative

  of the “Great Steam Invention”—

  foundation of imperial rule.

  The text ended abruptly.

  The truth lay bare—

  and brutal.

  This steam?roaring gear empire

  was not powered by coal or ingenuity,

  but by a slumbering, dangerous relic

  from an ancient civilization.

  Every explosion blamed on “pipe aging”

  or “operator error”

  was a pulse?core instability leak.

  Every increase in power

  came at the cost

  of further damaging the ancient device.

  The rulers knew everything.

  They wove their throne from lies,

  guarded their secret with violence,

  and crushed anyone who sought the truth—

  like Kyle Roan,

  like Amy’s brother—

  beneath the gears.

  “So… there was never a great steam revolution,”

  Sunri whispered, voice hoarse.

  “Only a century?long theft—

  and a lie.”

  Ye Lingyun’s grip tightened on his sword,

  veins bulging.

  “To hide the truth,

  frame the loyal,

  kidnap innocents…

  Such acts are beneath even demons!”

  Amy was already crying,

  for her missing brother,

  for every silent death

  in the Lower District explosions.

  At that moment,

  heavy footsteps and the hiss of pressurized steam

  echoed from the far side of the platform.

  “I must admit—your investigative skills are impressive.”

  Jackson, the Guardian,

  stepped out of the shadows,

  fully armored,

  eight elite guards behind him,

  weapons trained on the trio.

  “But this is where it ends.

  Some truths are buried

  because they should never be known.”