ValidClay

The low droning of the breach sirens hung in the back of every employee's head, ingrained from countess drills and the constant scrapings beyond secure doors. When an alarm started wailing, at 7:19 in the morning, however, it still caught them off guard. Not a breach siren, it sounded like two discordant voices screaming at once, with a sense of urgency about it. The alarm faltered, and cut off into silence, before an intercom announcement boomed through the halls. "ALERT: Non-D-Class personnel of clearance one or higher, please report to the Emergency High-Capacity Lifts at once. Abandon all other activities."

This message repeated once more, and mutters ran through the standing crowd. The Slots, they called them. Lifts with perpetually closed doors, going who knows how deep. They apparently connected the Containment areas with the Reactor and the maintenence levels, but people were doubting this now.

Tentative goodbyes were said, and thoughts were collected as long lines of breathing bodies flowed towards the elevator doors, as lights above them switched off.

The square chamber moaned as something massive and metal shifted out of place countless dozens of floors below them. The lift was wide, and had no walls, so people clustered to avoid the rising, uneven stone edifice of the shaft around the lift as the sound reached them. The shaft seemed to catch the grating metallic cacaphony, rolling it around and almost savoring its in taste before letting it fade.

The air was getting thicker now, hotter. The altitude was dropping, and the crowd seemed to push inward, away from the overbearing pressure. Any hopes that the drop actually lead to a maintainance floor were crushed by the pressure far before this.

Suddenly, and without warning, the elevator stopped. A door had risen above the textured metal floor, opening up to a vast underground space.

The elevator door peered out into the cavern, like a porthole in a cruise ship. A catwalk extended from the opening, joining the likes of many others, from many more elevator shafts. The black catwalks, dotted with orange lights, crisscrossed the open air, leading into great tunnels in the stone wall next to them. The wall seemed to slope off to the left, forming an overhang, and the tunnels and suspended tracks followed it, veining their way down to some unseen floor.

Below them, spotlights shone through dusty air, illuminating what seemed to be the bottom of the cavern. Buildings were revealed, and they looked familiar, if old fashioned. The way the light refracted off the marble and plate glass windows far below suggested the cityscape spanned far past what was being shown. A researched startled and almost fell past the guardrail as what looked to be a red metallic bird swooped past him.

The intercom sounded once more, this time seeming to echo across the cavernous space with no clear point of origin. "I know many of you must be afraid, or concerned for your safety, but do not fear. You have been selected to participate in Project 1678-Theta, a top secret contingency in the case of an uninhabitable or otherwise dangerous surface. Due to an ongoing XK-class scenario beyond your clearance, you will live down here until the surface is made livable again. In the meantime, however, welcome to UnLondon, the Last City. I hope you enjoy your stay."