1954
A diving bell sank to the ocean floor, and, after a few moments, a man in a diving suit exited. The man looked back at the diving bell, realizing the spot where he'd landed wasn't great, causing some concerning dents and scrapes in the metal frame. Because he wasn't sure if or when he'd be back there, he quickly grabbed a small box from inside. He always approached his dives with a "check things out or die trying" attitude (and more recently an "and die trying" outlook instead). He had just crossed the rocky underwater landscape when something caught his eye.
What the hell? he thought. It wasn't the shipwreck, or plane wreck, he was used to exploring; it was something more interesting. It was a hint of a city that shouldn't exist.
The man trudged through more of the rocky area along the side of the city; the landscape opened up as the seabed dropped, showing much more of the city. The man went over to what ended up being an airlock chamber used for people going outside the city for maintenance work. He cycled through and entered the city.
The man arrived in the maintenance workers' locker room. Realizing he probably shouldn't be running around in a diving suit, he took it off. Yes, he technically stole some clothes out of a locker, but he kept reminding himself some idiot left the damn locker unlocked, wide open, even. He took a wallet and a small notebook from the box he carried and put them in one of the pockets of his pants.
He wandered through a series of back offices before finding himself in the maintenance area of a train depot. The man became even more confused. Not only was there a whole city under the sea, it had a whole-ass enclosed train system. He continued to a complicated, roundabout-style track switching area where the trains could be lowered down from the main station terminal. The basement. The place was big enough that I was in the fucking basement.
He hoped it wasn't super obvious when he tried to blend in with people commuting home after getting off the night shift in the maintenance rooms, instead of going the wrong way on the train in the middle of the morning rush hour.
He didn't really know where he was going, slipping on and off trains, and later in bathyspheres, along with the crowds as people made transfers along their commute routes.
