Visitor from a Parallel World

Heels clicked crisply against the subway platform tiles in the darkness, like the only rhythm in the night.

Lin Xiu stood three steps from the stairs at Exit D. The electronic display's white glow cast shifting spots across his vision as the last train's departure time ticked over to "21:57" — three minutes left.

The air reeked of rust and dampness. Wind from deep within the tunnel carried an icy chill through the collar of his military coat. He instinctively pulled it tighter, while the nanoparticles around his wrist grew faintly warm with his body heat, like a living thing crawling along his skin.

"Here they come!"

A hoarse male voice exploded from the shadows to his left, like a thunderclap splitting the silence.

Lin Xiu's pupils constricted. A rough palm suddenly seized his wrist, its grip hardened by years of labor, nearly crushing his bones.

He turned sharply and got a clear look at the man: grayish-brown hair tangled into clumps, ripped jeans stained with dark red blotches, and an old scar running from his left brow to his jaw. The scar now bore an unnatural bluish-purple hue, as if blood vessels were twisting beneath the skin.

"Let go!" Lin Xiu had already pressed his other hand against the armor on his wrist, but the nanoparticles surged on their own the instant he made contact — the hum of Tactical Form activating trembled against his eardrums.

The next second, the air warped like water disturbed by a thrown stone. Three blue-white beams burst from the void, grazing Lin Xiu's right shoulder before slamming into a platform pillar. The screech of metal against concrete made his teeth ache.

The biological interface at the back of his neck suddenly burned, and data from the Oracle System exploded across his vision: "Non-three-dimensional spatial energy fluctuations detected. Attackers identified as High-Dimensional Projection Entities. Source coordinates... do not exist within the current spacetime."

"Don't ask who I am!" the man gripping him roared, his voice carrying the rasp of a dying beast. "Help me hold off these freaks first!" His fingers dug deeply into Lin Xiu's wrist bone, as though he wanted to embed his very life into him.

Lin Xiu ground his molars.

The Tactical Form shield unfolded around him. The instant the pale golden film of light collided with the beams, he heard the sharp crackle of nanoparticles disintegrating — higher-order energy crushing lower-order technology across dimensions.

Oracle, countermeasure protocol! he thought. Data raced wildly across his vision. Disrupt high-dimensional targeting... I need the Nanite Swarm!

Nanoparticles poured from the seams of his armor like a cloud of golden mist bursting apart.

The beams veered off course, grazing Lin Xiu's clothes before striking the ground and melting scorched holes into the tiles.

The man dragged him deeper into the tunnel. Lin Xiu could feel cold sweat coating the man's palm, and the sweat mingled with the scent of leather and rust as it flooded his nostrils.

"Left! There's a ventilation duct behind the third pillar!"

The iron grille over the vent was so rusted that it collapsed with a shove. The sound of snapping metal echoed through the empty underground station.

As the two tumbled into the dark duct, Lin Xiu heard a sharp crack behind them like shattering glass — attacks from the High-Dimensional Projection Entities struck the outer wall, making the metal pipe hum violently. The tremors traveled through the soles of his feet, as though the whole world were shaking.

The man tore off the ragged scarf around his neck and stuffed it into the vent opening. The stench of mold and rust immediately filled the air.

Lin Xiu pressed his back against the damp pipe wall. Tactical Form automatically contracted back into its base mode, while nanoparticles moved beneath his skin to repair the damaged portions.

He stared at the bluish old scar on the man's face. "Who exactly are you?"

The man pulled out a palm-sized metal device, its surface covered in dense scratches that looked as though they had been gouged out with fingernails.

When he pressed the switch, a ghostly blue light revealed the dark circles around his eyes. "Marco Delgado. A fugitive from a parallel world... no, a parallel timeline."

The interface at the back of Lin Xiu's neck began burning again.

The Oracle System suddenly displayed a notification: "Quantum entanglement fluctuations detected. Frequency compatibility with Nanocore: 87%."

"They aren't looking for me." Marco shoved the device into Lin Xiu's hand, the metal still retaining his body warmth. "They're looking for you. Your Nanocore... was never supposed to belong to this world." His Adam's apple bobbed. "In the timeline I came from, you never awakened Balder Armor. Loki controlled you with the Mind Stone, and you became the fuse for the Destroyer — the wormhole that tore open over New York wasn't the end. It was the beginning."

Lin Xiu ran his fingers over the device's surface. Tiny stardust-like particles were embedded within its grooves, sending a faint electrical sensation through his fingertips.

"Why me?"

"Because you're the variable." Marco suddenly seized his wrist, his nails nearly drawing blood. "Across all timelines, only this version of you merged with the Nanocore. The Oracle System... it can analyze any energy, even the Time Management Authority's correction rays." His voice began to shake. "Please... don't let that future happen."

A faint electronic buzz came from outside the ventilation duct.

Lin Xiu's pupils narrowed slightly — it was the frequency of a detector scan.

He dragged Marco into the corner of the duct, nanoparticles condensing into fine needles at his fingertips.

"Someone's here."

The footsteps outside were light, like the paws of a feline touching the ground.

Lin Xiu heard metal scrape, followed by an almost inaudible beep — the detector's activation tone.

Marco's face went deathly pale. "It's the Time Management Authority... they traced the energy fluctuations here."

"Stay quiet," Lin Xiu whispered into his ear. The nanoneedles pierced the duct wall, carving faint patterns into its metal surface.

The Oracle System's data stream told him this was Kamar-Taj's Concealment Spell — something he had picked up from Vela Knox three days ago.

The footsteps outside stopped.

Lin Xiu could hear his own heartbeat, pounding against his ribs again and again.

After a full half-minute, the footsteps began again and gradually faded away.

Marco slumped against the pipe wall, his forehead drenched in cold sweat. "They didn't find us?"

"Maybe." Lin Xiu took out the device. Stardust-like matter flowed within its ghostly blue glow. "But someone did."

In Kamar-Taj's meditation chamber, Vela Knox pressed her fingertips against a crystal ball.

Ripples spread over the mirrorlike sphere, gradually clarifying into an image of Brooklyn's underground ducts: the shadows of two men curled up in a corner, one of their wrists glowing faint gold.

"Spatial rift fluctuations." She turned to the Ancient One behind her, her red robes trailing a dark golden shadow across the floor. "Someone is guiding Lin Xiu toward a specific future."

The Ancient One's closed eyes moved slightly.

Six Time Stones floated around the cushion where she sat cross-legged, each one flowing with a different starry orbit.

"Let them place their bets." Her voice was like a bell in the morning mist. "The true player... has yet to make a move."

Inside the ventilation duct, Lin Xiu held the device to his ear.

A faint hum came from within the metal, like the background noise of some encrypted communication.

Marco suddenly grabbed his hand. "Remember, the entanglement between the Nanocore and the Tesseract... is the key." His voice began to blur, and his body became like an old film put on fast-forward. His skin visibly loosened, and white hair spread from the tips to cover his head. "Timeline rejection... I'm going back."

"Wait!" Lin Xiu grabbed his sleeve, but the fabric crumbled into dust in his hand.

Marco's face began to turn transparent, like thin gauze soaked in water. "Can that future... really be changed?"

"It can." Marco's smile froze just before it faded. A tear at the corner of his eye hung suspended in midair. "Because you are... a Quantum Sentinel."

When the last trace of light vanished, Lin Xiu opened his hand.

A silver fragment lay in his palm, its edges still dusted with fading starlight.

The Oracle System's alert exploded in his mind: "High-order energy fragment detected. Immediate fusion recommended."

He stared at the fragment as the burning pain in the interface at the back of his neck suddenly intensified.

His phone vibrated in his pocket. It was an alert from the laboratory: "Encrypted-layer data anomaly. Signs of external intrusion detected."

Lin Xiu placed the fragment into the armor core, and nanoparticles immediately surged over it, wrapping it up.

He rose to his feet. The moldy smell inside the duct suddenly became distinct — mixed with a faint trace of sandalwood incense, like the incense burning in Kamar-Taj's prayer halls.

"Oracle, analyze Marco's words." He took out his phone, its screen lighting up the dark currents in his eyes. "The parallel timeline, the Nanocore's anomalous origin... and who is breaking into the laboratory?"

The system fell silent for two seconds before giving an answer that made his breath catch: "Data chain indicates that the intrusion source... originates from your Nanocore."