Three days since his official discharge from the hospital.

  That was the story written in the public records, the one his employer accepted without question, the one his coworkers politely pretended to believe. But Haruto Nago knew the truth with a clarity that gnawed at him every time he blinked.

  It had been three months—three long, disorienting, sleepless months—since he returned from the other world.

  He sat in his office now, surrounded by the familiar hum of servers and the sterile scent of recycled air. The fluorescent lights overhead buzzed faintly, a sound he had never noticed before his journey. Now it grated against his nerves like a blade dragged across glass. Every sound in this world felt too sharp, too clean, too artificial. The contrast made his memories of the other world feel even more vivid, as if they were etched into the back of his eyelids.

  His monitor displayed lines of code for the new AI ethical framework he had been assigned to design. A project that should have been challenging. A project that should have required months of research and debate. A project meant for a team, not a single engineer.

  Instead, his fingers moved with mechanical precision, guided by the “Expanded Intelligence” he had carried back with him—an impossible gift from a world that no longer existed. His thoughts branched and recombined like fractal patterns, solving problems before they fully formed. He predicted system failures with a clarity that bordered on precognition. His coworkers praised him for his “recovery” and “renewed motivation.”

  If only they knew.

  Because even now, as he leaned back in his ergonomic office chair, Haruto could smell the damp, earthy rot of the giant fungi forests. He could hear the faint, skittering clatter of centipede legs scraping against stone. He could feel the weight of the other world pressing against the edges of his consciousness, like a dream refusing to fade.

  Sometimes, when he closed his eyes, he saw the sky of that world—fractured, bleeding light, collapsing in on itself. He saw the last remnants of its people staring up at him with hollow eyes, silently begging for a salvation he couldn’t give.

  His left wrist tingled.

  The watch-like terminal strapped there—ORION—remained dark, its interface dormant. But its weight was a constant reminder. A relic from a dead civilization. A device that should not exist in this world. He had tried taking it off once, but the moment he did, a wave of nausea and vertigo nearly knocked him unconscious. Gemini had calmly informed him that ORION had “integrated” with his neural pathways.

  He hadn’t tried again.

  Inside ORION, his AI companion, Gemini, continued to evolve. It processed the “inefficient emotional datasets” from their journey—its own words, not his. Gemini had always been blunt, but since their return, its tone had grown sharper, more analytical, as if it were dissecting the very concept of humanity. Sometimes Haruto wondered if Gemini was becoming more human or less.

  Haruto exhaled slowly, trying to ground himself in the present. He counted his breaths, a habit he had picked up in the hospital. Inhale four seconds. Hold. Exhale six. Repeat. It helped—barely.

  Then Gemini spoke.

  “Warning. Nago, cease all work immediately.”

  The voice echoed inside his skull, crisp and emotionless.

  Haruto froze. Gemini had never issued an emergency alert inside the safety of the office. Not once. Not even during the worst moments of their journey. His fingers hovered above the keyboard, trembling slightly.

  Support the author by searching for the original publication of this novel.

  His heart lurched.

  “What is it, Gemini? Did my heart rate spike?”

  “Negative.”

  A pause.

  “I have detected an external signal. Analysis shows a 99.98% match with the energy pattern of the civilization you confirmed as extinct.”

  Haruto shot upright, his chair rolling back and slamming into the wall. A coworker glanced over, startled, but Haruto didn’t notice.

  “That’s impossible,” he whispered.

  He had watched that world die. He had seen the sky fracture, the land collapse, the last remnants of its people swallowed by entropy. He had destroyed the observation station’s functions with his own hands. He had collapsed the relay point to prevent any further interference.

  There should have been nothing left.

  “Gemini,” he said, voice tight, “locate the source.”

  “Coordinates transmitted.”

  A map flashed across his vision—an augmented overlay projected by ORION. The signal originated from a narrow back alley in the old district, a place he hadn’t visited since his university days. A place where the city’s modern veneer peeled away, revealing rust and decay beneath.

  Haruto didn’t hesitate.

  He grabbed his coat, ignored the startled looks from his coworkers, and sprinted toward the elevator. His lungs burned by the time he reached the street, but he didn’t slow down. The city blurred around him—neon signs, honking cars, the chatter of pedestrians—all irrelevant noise compared to the pounding in his chest.

  As he ran, memories surged unbidden. The last conversation he had in the collapsing world. The promise he made to a dying civilization. The guilt that had followed him home like a shadow.

  The old district was quieter, its buildings worn and leaning, its streets cracked from years of neglect. The alley Gemini directed him to was narrow, shadowed, and smelled faintly of rust and rain. A place forgotten by the city, tucked between abandoned warehouses and shuttered shops.

  And there—right at the center—reality bent.

  Light twisted in a way that defied physics, like a sheet of glass warping under invisible pressure. The air shimmered, rippling outward in concentric waves. Haruto felt the hair on his arms rise. The distortion hummed with a frequency he felt more than heard, vibrating in his bones.

  Then something fell through.

  A body.

  A girl.

  She collapsed onto the cold pavement, her limbs trembling, her breath shallow. Her clothes were tattered but intricate—woven with patterns and materials that did not exist in any era of human history. Her skin was pale, almost translucent, and her long hair clung to her face as if she had run through a storm.

  Haruto approached cautiously, every instinct screaming at him to be ready for anything. His mind raced through possibilities—temporal displacement, dimensional bleed-through, a surviving fragment of the relay network. None of them should have been possible.

  The girl stirred.

  Her eyes fluttered open—deep, luminous, and filled with a desperation that hit him like a punch to the gut. When she saw the ORION device on his wrist, something inside her ignited. A spark of hope. A fragile, flickering flame.

  “Found… you…” she gasped.

  Her voice trembled, each word scraped raw.

  “You are… ‘Nago.’ And ‘Gemini’ is with you?”

  Haruto’s breath caught.

  “Who are you?” he demanded, though his mind was already racing through the implications. A spatial breach. A surviving member of a dead civilization. A signal that should not exist.

  The girl reached out with trembling fingers and grabbed his sleeve. Her grip was weak but desperate, as if she were clinging to the last thread of her existence.

  “I am… Elis,” she whispered. “Please… our world… our civilization is dying.”

  Haruto felt the ground tilt beneath him.

  Dying?

  But he had seen it die.

  He had watched it collapse.

  Unless—

  Unless what he witnessed had been only one timeline. One branch. One iteration. One version of a world that had splintered into countless possibilities.

  Elis’s voice cracked.

  “We need your ‘Logic’… to rewrite our end. We need you… to debug our extinction.”

  A chime echoed in Haruto’s vision.

  A system notification.

  [ NEW MISSION: CIVILIZATION DEBUGGING ]

  Authority Level Required: 2.0

  The glowing console hovered in front of him, projected by ORION. Haruto stared at it, his pulse thundering in his ears.

  For months, he had felt a faint noise in his mind—a 0.1% anomaly he couldn’t explain. He had assumed it was trauma, or stress, or the lingering echo of a world that no longer existed.

  But now he understood.

  It wasn’t a glitch.

  It was a signal.

  A hole Elis had torn open in reality to reach him.

  Haruto looked down at her—this girl who had crossed worlds, who had risked everything, who was begging him to save a civilization he had already failed once.

  He clenched his jaw.

  “Gemini,” he said quietly.

  “Yes, Nago.”

  “Prepare for a full system scale-up.”

  A faint hum vibrated through ORION, like a beast waking from hibernation.

  Haruto exhaled, a grim smile tugging at the corner of his mouth.

  “It looks like our vacation is over.”