People were coming from everywhere to see the new city. Almost all of them had heard of it via the article in the news papers that had started to circulate around the nearby towns. The idea that something outside of what they all knew could be a part of their daily lives was almost as exciting as a new city being built so close to them.
Of course, the article hadn't mentioned the downsides to coming to witness history in the making and very few of the visitors were prepared for the amount of construction work that was being undertaken. It shouldn't have been a surprise to them, of course. An entire city being built requires a lot of work to begin with, but when you add in the complications of building it on ancient volcanic rock, so many more things need to happen to make it work. Fortunately, the city was being built by experts and they were doing everything properly.
On the outskirts of the city, at the theoretical limits, a work team drilled through the rock to find how deep it was. They had all lost count of the amount of these holes they had drilled over the last few weeks, and they still had dozens to go. Their primary goal was to see if the thickness of the rock varied terribly much over the area the city was going to sit on, and where it was thinner, use that as a place to dig down so that all the underground tunnels could be made. So far, in this section of rock at least, it was a fairly standard thickness. This was both good and bad. Good in the sense that the city would be sitting on a solid foundation, when all the large buildings went up, and when it inevitably expanded. But it was bad because if they couldn't find any viable spot to dig at, then construction would come to a halt and could cause the city to be abandoned.
“Why they hell,” one of the workers complained for what felt like the millionth time, “did they decide to build the city on this goddamn rock?”
“You're asking the wrong guys, man,” another replied. “We don't know shit, remember? We’re paid to drill and that's it. Leave the thinking to the idiots in charge.”
“Yeah, so long as we get paid for this, who the hell cares why were doing it,” a third man agreed.
“I wouldn't complain if this rock wasn't the hardest bloody stuff I've ever come across.”
“Well, that's why we call you a whinger when you're not listening, Clyde,” the third man chuckled and started to set up the drill stand for the afternoons work.
There were eight or nine of these groups scattered around the circumference of the city. None of them had found any spot that deviated greatly from the average depth. But one team had found a spot which was significantly deeper than any other hole they had drilled. Than any of the teams had drilled. In fact, they had run out of drill bits and still hadn't reached the bottom. There was now an argument as to how to proceed.
“We should definitely tell someone.”
“What for? They want a thinner layer, this is thicker.”
“Yes, exactly. Until now, this rock has been the same thickness. Something this thick means something.”
“It means were drilling in the wrong spot.”
The argument would have come to blows, had it not been for the intervention of the supervisor who had already sent a runner off to his boss to inform him of the discovery. He very quickly got his team back to work and marked the deep layer of rock for later.
The message about the thick spot didn't really interest many people back at the central HQ. Almost everyone agreed that a thick spot was the opposite of what they were looking for and therefore uninteresting.
That is until one of the more experienced designers/architects heard it and insisted that management halt all drilling and construction in that area until such time as the anomaly had been fully investigated.
“Goddammit, George. Why? Delaying the construction in that zone will set us back weeks. We don't have time for this.”
“You either investigate now, or you risk thousands of lives in the future. Your choice,” George said.
“Explain yourself or nothing happens.”
“Think about it. That rock is volcanic.”
“So what?”
“So, it wasn't always rock. It was liquid when it flowed all the way down here from the hills.”
Several of the other people present started to switch on to what George was saying.
“Liquid rock, that is lava, flowed down the hills, over the plains on which were standing and on which were building and down a hole. That hole filled, the lava set and that brings us to today.”
“So there's a hole,” one of the few who hadn't realised what all that meant said.
“Potentially more. Probably a cave.”
“You want to go caving?”
“Why are you such an idiot? A cave directly under the city. If the city ever got to the size our wise and mighty benefactors want, there is a chance that the entire foundation on which its built could collapse into this cave under its own weight. Do you want to wait until that happens? Or deal with it now, while no one is dead?”
All of the drill teams had been called to the thick spot and they were tasked with digging the planned access hole here, right against the thick rock. It took the better part of a day, but eventually they made a hole that could accommodate someone being lowered down.
They dug through the earth that the rock had laid on for countless thousands of years until, very quickly, they found the cave beneath them.