The impact with the water felt like smming into a concrete wall.

  The torrent that spat them from the "gut" of Pacio Barolo hurled the group into an icy, absolute bckness from a height of thirty feet. The cold didn't just burn their skin—it instantly punched the air from their lungs and locked their muscles in a steel cramp. The water here was heavy, thick with dissolved minerals and centuries of dust.

  Mateo surfaced first, greedily gulping the stale void and spitting out the bitter, throat-searing liquid. He immediately fumbled for the heavy industrial fshlight on his belt and jammed the stiff rubber button. The beam struggled to cut through the inky gloom, frantically catching oily bck waves in the darkness.

  — “Elena! Leo!” he roared, his voice barely carrying over the dull, echoing roar of the waterfall pouring from the pipe.

  — “I’m here! Mateo!” Elena surfaced about fifteen feet away, treading water frantically while holding her rifle above the surface with one outstretched arm. “I’ve got Leo! Where are the others? Cobra?!”

  The water around them began to boil. First, the top of Cobra’s head broke the surface. The girl thrashed her arms, struggling to stay afloat, her eyes wild with panic.

  — “Nico!” she choked out, gasping for air. “He didn't come up! Damn it, he went straight to the bottom!”

  Mateo dove without thinking. His fshlight beam caught a sinking figure in the murky suspension—a heavy, waterlogged jacket and the iron rebar the kid had cmped in his fist from panic were dragging Nico down like an anchor. The engineer lunged for him, grabbed his colr, and yanked him upward with all his might.

  Nico resisted, instinctively kicking in his panic, but Mateo, treading powerfully, shoved him to the surface. Nico broke the surface tension with a horrific gasp and dissolved into a hacking cough, vomiting bck water.

  — “The iron... drop the rebar, boludo!” Cobra screamed, swimming to him and grabbing him by the scruff of the neck.

  — “I can’t... fingers cramped...” Nico wheezed, his eyes rolling wildly, still clutching his bent piece of steel. The heavy, soaked jacket was dragging him down surer than any stone.

  — “To the shore!” Elena commanded, her voice cutting through the panic like a scalpel. “Everyone to the shore! Move!”

  Mateo raised his light. They were in a gargantuan karst cavern. The vaults were lost somewhere in an unimaginable, crushing height, while the bck surface of the underground ocean stretched into the distance, swallowing the light. But there was a shore. About fifty yards away, a gentle isnd rose from the water. A strange, unnaturally white isnd.

  They paddled with the st of their strength. Their soaked clothes and gear dragged them toward the bottom. Leo swam beside his mother in absolute silence, his movements mechanical and economical, as if the water itself parted before him, sensing his altered structure.

  When Mateo’s boot touched bottom, a dry, sickening crunch echoed beneath his sole. He scrambled onto dry nd, colpsed heavily to his knees, and lowered his fshlight beam to his feet.

  It wasn't sand. And it wasn't pebbles. The entire isnd, receding into the darkness, consisted of bones. Millions of bones, compressed over centuries into a solid, porous monolith. Huge, time-yellowed ribs jutting into the void; shattered skulls the size of compact cars; thousands of small, sharp vertebrae crunching under the weight of their bodies.

  — “What the hell is this?” Nico crawled onto the shore, his teeth chattering from the lethal cold. “A dinosaur graveyard?”

  Mateo picked up a massive, porous vertebra the size of a car wheel.

  — “The biomechanics don't add up,” he muttered, trying to find engineering logic in the chaos. “A bone of this structure couldn't support its own weight. This is some kind of deep-sea leviathan that isn't in any manual. And over there...” his light slid further, catching a pile of compressed human skulls. “There are thousands of them. Like someone gutted them and dumped them into one giant pit.”

  — “He didn't gut them, Dad,” Leo said quietly. He stood ankle-deep in bone fragments, water dripping from his bck left arm without leaving a trace. “He doesn't need meat. He only draws out the spark. Bio-electricity. Life. And this...” the boy swept his dark, unchildlike gaze across the endless white isnd. “Just empty shells. Expended inorganic waste. Dead batteries he’s been dumping here for an eternity.”

  — “Look,” Elena said sharply, pointing toward the center of the white isnd. The beam of her under-barrel light caught something in the darkness that absolutely didn't belong. Amidst the white bones of prehistoric monsters, like a headstone for another era, rose a bck steel tower. A conning tower. Rust had mercilessly gnawed at its sides, but the heavy Krupp steel resisted time fiercely. On the soot-stained metal, covered in a yer of petrified white algae, a faded white paint was still visible: U-977.

  The submarine itself y with a list to the port side, half-grown into the bone foundation, like a beached steel leviathan.

  — “It’s here,” Mateo exhaled, feeling hot sweat run down his back despite the cold. “A Nazi sub. The legend of the 'ghost ships' that fled to South America in '45... They really drove it in here.”

  — “Why?” Cobra asked. “Why hide a combat sub in an underground cave?”

  — “It’s not just a hiding pce,” Mateo replied, quickening his pace toward the vessel. “The Substrate has an outlet to the Atntic. This was their ark. They wanted to move something important on it. Or someone.”

  Suddenly, the water behind them bubbled with a dull roar. It wasn't the spsh of falling drops. It was the simultaneous sound of bodies slicing through the surface with fury. Mateo spun around and sshed his light across the churning water.

  The water was boiling. Dozens of pale, long bodies snaked toward the shore, leaving foamy wakes behind them.

  — “Eels?” Nico squinted, raising his rebar. One of the creatures leaped from the water onto the bone beach with a wet thud. It wasn't an eel. It was a ringed worm the size of an anaconda, translucent, with dark organs pulsing convulsively through its pale skin. It had no eyes—only a round, contracting suction-cup maw lined with concentric rows of yellow needles. A second one leaped out. Then a tenth. They crawled over the bones with a sickening wet rustle, unerringly tracking the heat of living bodies.

  — “Cleaners!” Elena shouted, bringing her rifle to her shoulder. “They react to vibration and heat! Get to the sub! Run!”

  — “They want to eat! ?Carajo!” Nico yelled, swinging his backpack over his shoulders.

  They bolted for the submarine. Running over bones was a total nightmare—fragile skulls shattered, slippery ribs slid underfoot, threatening to snap an ankle at any second. The first shots rang out behind them. Elena fired in short, disciplined bursts, conserving ammo. Heavy bullets tore through the soft, translucent bodies of the worms, spshing acrid bck sludge onto the white bones, but there were too many of them. They rolled in from the water in a solid, blind wave.

  — “The hatch!” Mateo yelled, skinning his palms bloody as he scrambled up the sub’s slippery, sloping hull. “Leo, Nico, up, now!” Nico boosted Cobra, shoving her onto the deck, then climbed up himself, hissing in pain from his bruised ribs. Leo flew onto the conning tower with an unnatural, cat-like grace. Mateo reached the tower hatch. The steel wheel was overgrown with a thick yer of calcium deposits and rust, turned into a solid mass.

  — “It won't budge!” the engineer roared, throwing his entire weight against the wheel, feeling his ligaments strain. “It’s seized shut!”

  The creatures were already at the base of the sub. They began to climb the smooth hull, attaching themselves to the rusted metal with wet squelches. One of the worms, the rgest, lunged for Elena’s leg as she backed up, covering their retreat. She knocked it back with a precise butt-stroke, but the creature managed to ssh her thigh with razor-sharp spines.

  — “Bitch!” Elena retreated to the tower, limping but never ceasing fire. “Open it faster, Mateo!”

  Leo shoved his father aside. — “Move.” The boy dropped to his knees and pced both hands directly onto the salt-crusted metal of the hatch. The bck veins on his left arm bulged. — “Wach auf (Wake up),” he commanded quietly, in a nguage he had never studied.

  A dull, low-frequency tremor shuddered through the dead hull of U-977. This wasn't the mechanical sound of grinding metal. It was the sound of an awakening titan. Mateo watched with rising primal dread as the rust on the hull began to shift like scales. Beneath the yer of century-old oxidation, bck, pulsing threads of the Substrate emerged. The sub wasn't just lying there—it was infected. It had long since become part of the system. The wheel beneath Leo’s hands turned red-hot, emitting steam; petrified salt crumbled like white sand, and the wheel spun of its own accord with a horrific shriek.

  The hatch flew open with a powerful bst of compressed, stagnant air. — “Inside!” Nico screamed, jumping into the dark well of the hatch first and pulling the dazed Cobra with him. Elena fired blindly into the maw of a worm already leaning over the tower railing and dove in after them. Mateo grabbed Leo by the colr of his hoodie, shoved him into the hatch, and jumped in st. He smmed the heavy armored lid shut and spun the inner wheel to the limit just as dozens of bodies thudded against the outer armor, frantically trying to gnaw through the steel.

  They were in the cramped vestibule of the central control post. A dim, blood-red emergency light flickered to life—mps, dead for eighty years, responding to a bio-electric impulse. The air inside hit their lungs with a thick, oily weight—a mix of diesel fumes embedded in the bulkheads and metallic dust that immediately left an unpleasant taste of old copper on their teeth.

  — “Everyone in one piece?” Elena asked, breathing hard. She leaned against a bulkhead, quickly inspecting her torn pant leg. The wound wasn't deep, but it was bleeding heavily. — “We’ll live,” Nico said, sitting on the ribbed metal floor with his head in his hands. “But Engineer, if this rusted tin can isn't seaworthy, we just locked ourselves in a very reliable German coffin.” — “It’s running,” Leo’s voice came from the darkness of the main compartment. “It was just waiting.”

  Mateo stepped into the central post and froze. It was a museum of 1940s technology, raped by alien biology. Analog dials, brass valves, and massive pipes were tightly entwined with organic matter. Hard bck roots had grown through the control panels, completely repcing the rotted copper wiring. The periscope optics were filmed over with a murky, pulsing membrane, disturbingly simir to the cornea of a giant eye. In the leather captain’s chair sat a skeleton in a tattered Kriegsmarine uniform. Leo carefully, almost with a frightening respect, moved the light bones to the floor and took his seat.

  — “You’ve got to be kidding me,” Mateo whispered, his rational mind refusing to accept it. “You want to start this? The electric motors are rotted! The diesels won't start without high-pressure air, and the lead batteries crumbled a century ago!” — “It doesn't need diesel, Dad,” Leo said, pcing his hands on the diving pne wheels.

  From the frayed armrests of the chair, thin bck chitinous needles instantly sprouted and plunged into the boy’s wrists with a wet crunch. Mateo lunged forward to rip his son from the trap, but Leo stopped him with a heavy, commanding gaze. His pupils had completely flooded his irises, turning his eyes into two abyssal pits. — “I am its battery. I am the captain.”

  The submarine responded with a powerful, visceral hum. The red light blinked and became steady and bright. Pumps began to drone, running not on electricity but on the Substrate’s drive, sucking water from the balst tanks. A strong vibration ran through the deck, shaking rust dust from the overhead.

  — “The sonar... it’s active,” Cobra reported uncertainly, staring at the circur hydrophone screen, which suddenly glowed with a phosphorus-green light. “I don’t know jack about these radars, but something is blinking really fast here.” — “Contact,” Elena pushed off the wall and stepped toward the screen. “Large target. Moving too fast. Coming from the spillway.”

  A huge, pulsing blob was spreading across the screen. Mateo frowned, gauging the scale of the return. — “That’s too massive for a swarm of worms.” — “It’s not worms,” Elena cut him off, instantly recognizing the tactical signature. “That’s the Vanguard amphibious train. The Corporation’s heavy assault transport. They’ve unleashed their hounds into the water. We have two minutes until visual contact!”

  She spun toward her husband, snapping into commander mode. — “Mateo, you’re the engineer. Handle the hydraulics and balst, now! We have to go deep! Nico, check the torpedo tubes in the bow!” — “Me?!” Nico’s eyes bugged out as he pressed against the bulkhead. “I’m a sewer rat from the slums, se?ora! My job is digging in the dirt, not sailing iron whales and tossing torpedoes, ? puta madre!” — “There’s a giant valve beled 'Rohr 1'!” Elena barked. “Just check that the cap isn't a rusted piece of shit, or the pressure will crush us when we unch! Go!”

  Mateo dove for the diving system panel. The heavy brass levers yielded with difficulty—their lubricant was now a thick biological slime. — “Blow main balst!” he commanded himself, leaning into it with all his weight. Compressed air hit the tanks with a furious hiss. U-977 trembled slightly, but the multi-ton hulk didn't move an inch, locked tight onto the bone reef. — “It’s useless!” Mateo punched the dashboard in despair, gncing at the radar screen. “We’re high and dry! The air gave us buoyancy, but to shake it off the reef, we need external thrust. A fulcrum!” — “There is a fulcrum,” Leo echoed, his bck eyes half-closed. The chitinous needles in his wrists pulsed with blue light.

  In that moment, the boat shuddered. Those same bck Substrate roots that had entwined the keel for a century suddenly contracted. They acted as gargantuan muscur jacks, bracing hard against the white isnd.

  The metal groaned with a long, raspy screech, like an old, wounded hound struggling up from the eternal mud. The massive weight of iron crushed thousand-year-old skulls beneath the hull and, driven by an external biological force, slid heavily off the shore.

  Plunging into the bck underground ke and kicking up a fountain of icy spray, U-977 finally gained buoyancy, aggressively leveling its list once in the water.

  — “Full speed ahead,” Leo whispered.

  The hum of the biomechanical engines deepened into a low roar that vibrated in their chests. The propellers furiously churned the bck water of the underground ocean, and the submarine—the Reich’s steel ghost, guided by a mutant boy—plunged into the absolute depth, away from the shore of dead bones and straight toward the flooded tunnels of the Mainline.