The Duplicate City

The Northside Dome Service Gallery vibrated like a held note - thin through the soles of Jessie’s boots, then louder where the maintenance rails met the conduit housings. She crouched by the lower inspection hatch of Sector Twelve, fingers already numb around the gasket sealant wand, the display on her wrist throwing pale gridlines over the panel. The residential district above was quiet in the way only domed places could be: no wind, no birds, just the constant, regulated breath of systems and the occasional click of a thermostat cycling in some apartment she’d never see.

Routine maintenance meant small problems you could fix before anyone noticed they were there. Jessie liked that. She’d signed on for dome checks because the dome was honest about what it needed - at least, it was supposed to be.

Her wrist display flickered once as she worked, then settled. The camera on her shoulder - standard-issue for proof-of-service - blinked green. She pressed the hatch release and the metal seam gave with a soft, reluctant sigh. Cool air slid out from the space beyond, smelling faintly of warm plastic and filtered dust, and the sensor strip along the inner frame pulsed as it read her authorization.

“Good,” she muttered, mostly to keep her hands steady. The panel’s inner lining was warped by heat stress. She’d seen this before: a hairline breach in the thermal regulator that only showed up under load. She cleaned the contact rails, re-seated the regulator, and watched the sensor strip shift from amber to blue.

Then, through the service gallery’s long run of reinforced windows - narrow panes built for inspection, not for staring - she caught the shape of the skyline.

It wasn’t the city above. It couldn’t be. The dome’s interior always made distance lie: every street looked like it belonged to the same model, the same planned geometry, the same repetition that kept life smooth and predictable. But this - this was a matching skyline, down there where no one kept anything but utility void. Buildings with the same staggered rooflines. Roads with the same sharp bends. Even the tall, thin tower at the east end - there was no east end beneath the dome, not officially. Yet there it was, inverted by shadow and warped by depth, sitting under them like a reflection that refused to be dismissed.

Jessie froze with sealant halfway applied.

The window’s glass shimmered as her optics adjusted. The skyline didn’t just sit there. It moved. Not like a quake or a shifting reflection - like something enormous drawing breath behind a wall.

A low pressure throb rolled through the gallery, felt in her ribs before her ears caught up. The lights didn’t dim, but the hum of the conduits changed pitch, as if the whole system had inhaled and was holding it.

Her shoulder camera whined once, then tried to compensate. Jessie slapped the manual focus control, forcing the lens to lock. The image stuttered - one moment the skyline was crisp against the underside of the dome’s inner skin, and the next it smeared into a ghost of itself, like a recording skipping frames.

“No,” she whispered, because her mind wanted to file it under glitch, under tired eyes, under the dome playing tricks. She’d seen sensor errors before. She’d seen bad optics. She hadn’t seen an identical city under their feet.

She pulled her hand back from the regulator and leaned closer to the glass, letting her breath fog the inspection pane’s edge. The air stayed cool. The skyline stayed in place. Then the pressure throb returned, stronger this time, and the skyline’s lights - tiny points along window rows - flickered in a pattern that looked planned rather than random. Like a city responding to being watched.

Jessie’s throat tightened. Confirming what she’d seen wasn’t curiosity anymore. It was necessity. If this was real, if there was a place down there with people living in the same shapes as above, then the dome wasn’t just containing them. It was hiding them.

And she needed proof fast - proof she could keep, proof she could show someone without triggering the alarms that turned every anomaly into a quarantine.

Her authorized maintenance scan was still running in the background. The wrist display scrolled her service logs: completed tasks, sensor readings, compliance checks. Everything above-board. Everything safe.

She wanted the skyline on her own terms.

She switched her shoulder camera into a recording mode that wasn’t part of standard procedure, a narrower capture designed to reduce noise and stop the dome’s internal interference from smearing details. It felt like slipping a second key into a lock - something tiny and not supposed to exist.

The camera’s status light turned from green to amber.

“Come on,” Jessie said under her breath. Her fingers moved with practiced speed, tapping her wrist to save the frame buffer locally. If she could capture a stable moment - just one clear sequence - she could compare it later, stitch it, verify the angle....