The rain hadn’t stopped for fourteen days. Elias stared at the gray smear beyond his window, the world outside reduced to a relentless downpour that blurred the lines between sky and street. His apartment, a cramped one-bedroom on the fourth floor of the crumbling Hawthorne Building, felt like a coffin shrinking around him. He hadn’t left in weeks—not since the fever that pinned him to the bed, not since the power outages that made every shadow suspect. Work emails piled up unanswered; groceries dwindled to canned beans and stale crackers. Isolation was a familiar companion, but lately, it had grown teeth.

It started with the breathing. Late one night, as thunder rattled the panes, Elias pressed his ear to the shared wall with apartment 4B. There it was: a slow, deliberate inhale, exhale, matching the rhythm of his own lungs. He froze, pulse quickening. The building’s tenant list in the lobby said 4B was vacant—had been for months since old Mrs. Hargrove passed. Coincidence, he told himself. The walls were thin; sounds traveled. But then came the footsteps—soft, pacing, stopping just when his did.

Elias pulled away, rubbing his temple. Paranoia, the therapist from years ago had called it. Back when his marriage dissolved, when Claire left him for the man next door in their old place. That neighbor—always listening, always watching through peepholes drilled in the drywall. Elias had found the holes, plugged them with putty. But the feeling lingered, a worm in his brain. Now, here it was again.

He tried ignoring it. Focused on his laptop screen, forcing code into lines that blurred under fatigue. But the whispers came next. Faint at first, like wind through cracks, then clearer: his name, drawn out. ‘Eeee-lias.’ He bolted upright, chair scraping. ‘Who’s there?’ Silence. Then a chuckle, low and mocking, identical to his own laugh when he’d had one.

Sleep evaded him. He lay on the lumpy mattress, staring at the water-stained ceiling, mind racing through possibilities. Squatters? A homeless person crawled in through the vents? The building super, Hargrove’s son, rumored to be unstable? Elias’s thoughts spiraled inward, each one heavier, the air thicker. The room felt smaller, walls inching closer, rain a ceaseless drumbeat urging him to listen.

Morning brought no relief. Gray light filtered in, casting long shadows. He brewed coffee—the last grounds—and sat at the kitchenette table, notebook open. He’d document it. Prove he wasn’t crazy. Tapped the wall: three sharp raps. Waited. Three raps back, precise. His skin prickled. He wrote: ‘Day 15. Contact established. Mimicking behavior.’

The game escalated. He slid a note under his own door, pretending it was to 4B: ‘I know you’re there. Leave or I call cops.’ Retrieved it later, blank—no, wait, words scrawled in his handwriting: ‘You first.’ Heart slamming, he taped it to the wall, mirror image glaring back.

Days blurred. He rationed food, leaving ‘offerings’ by the baseboard—crumbs, a half-sandwich—gone by morning. How? The neighbor taking them? Elias lost weight, cheeks hollowing, eyes sunken in the bathroom mirror. He avoided that mirror; it felt like eyes watched from its depths. Instead, he fixated on the wall, ear pressed for hours, deciphering messages in the knocks. Morse code? No, patterns of his childhood phone number, his ex’s birthday. Personal. Invasive.

Nights were worst. The breathing synced, then desynced—faster, agitated, as if mocking his insomnia. Whispers evolved: fragments of conversations. ‘Claire was right to leave.’ ‘You’re nothing.’ His voice, distorted. Elias shouted back, pounding fists until knuckles bled. ‘Shut up! I hear you!’ The response: laughter, echoing his own panic.

He researched the building online, battery dying on his phone. Hawthorne, built 1920s, history of ‘incidents’—tenants vanishing, whispers of hauntings. One forum post: ‘4B is cursed. Don’t listen.’ Useless. His mind churned: Was it supernatural? Or psychological, his isolation birthing a phantom foe? The fever had broken, but delirium lingered, room spinning in peripheral vision.

Claustrophobia gripped tighter. He paced a shrinking circuit: bed to table to sink. Door to hallway tempted, but what if the neighbor waited? Super’s number disconnected. 911? They’d think him mad. No proof.

On day 22, a shadow flickered under the door crack—no, in the wall crack he’d pried open with a spoon. Peephole now. An eye stared back, unblinking, his own color. ‘Hello?’ Elias whispered. The eye blinked. ‘What do you want?’ Rustle. Then, voice muffled: ‘Your life. Like you took mine.’ Gasps. Memories flooded: Claire’s neighbor, the confrontation, the shove down stairs. No body found, but guilt buried him.

Enough. Elias grabbed the hammer from toolbox, hands trembling. Rain thundered approval. He swung at the wall, plaster exploding, dust choking. Swing after swing, muscles burning, revealing insulation, wires. No cavity, no 4B. Wait—this was an exterior wall? Blueprint memory hazy.

Deeper. Fiberglass tore, revealing not studs, but another layer of drywall. Impossible. Another apartment? Sweat stung eyes. Hole widened: darkness beyond, breathing louder, closer.

He reached in, fingers brushing cold glass. Glass? Pulled back shredded hand. Pounded more. Shattered. Light pierced—not from next room, but flooding his own. He staggered, hammer dropping.

The ‘wall’ crumbled fully, revealing… a full-length mirror, bolted floor-to-ceiling, camouflaged by paint matching the plaster. The apartment was a studio—one room, divided by illusion. The ‘other side’ was his reflection, distorted by angle, dust, shadows. Crumbs by baseboard? His own forgotten. Notes? Self-scrawled in mania. Breathing, whispers, knocks—all echoes, amplified by the room’s acoustics, his mind filling gaps with paranoia from past traumas.

Claire’s neighbor? Never happened. Divorce papers on table: she left because of his growing delusions, agoraphobia chaining him here for years. Isolation not storm-imposed, but self-built prison. The eye? His own, magnified in cracked glass.

Laughter bubbled—his, hysterical. Walls closed metaphorically now, truth crushing. Phone rang—finally charged. Claire: ‘Elias? You okay? Building manager called—mirror fell?’ He dropped it, sinking to floor amid debris.

Rain eased outside. But inside, the whispers remained—his own mind, unburied, eternal.