The door opened a few minutes later, with a nervous looking Klihur poking his head into the room. “Hello?"

“Hi.” Zoe responded.

“Please follow me.” Klihur said, gesturing down the hallway.

The three women started to follow him out of the room, but Klihur held up his hand to stop Eliza and Lila. “Only Zoe, please.”

“Ooookay.” Eliza said. “Make it quick, then.”

“I mean I can do it but it’s still gonna take a bit.” Zoe said with a nervous chuckle.

“Stay safe.” Lila smiled.

“Please, come.” Klihur said, pointing further down the hallway.

“Alright, alright. Lets go, then.” Zoe said, closing the door behind her. It snapped shut with a small metal bar slamming down across the front of it that Zoe hadn’t noticed in her few minutes inside.

“Is that really necessary?” Zoe asked, pointing at the bar.

Klihur nodded. “Please, come.”

“Alright then.” Zoe said, getting a momentary flashback to when she’d overextended herself with the wanderer. Was this the same mistake? What if it was just some trap, taking advantage of her naivete to lure her somewhere she wouldn’t be able to escape from?

Klihur walked through the metal clad hallway, past several closed doors with similar looking rooms behind. Was it normal for them to bring people down here? Did they often get visitors that would come to the deeper facility? Why were there so many rooms for people to stay in?

Eventually, the hallway opened up into an enormous cavern, stretching as far forward as Zoe could see and hundreds of feet off to either side, as well as further down into the ground.

“Holy crap.” Zoe exclaimed, staring at the system of fragile looking walkways that led across the vast cavern, stretching from wall to wall. Hundreds, maybe thousands of similar looking metal hallways branched off the cavern from floor to ceiling, down the entire length of it, with a veritable swarm of goblins rushing around from hallway to hallway.

“Please follow.” Klihur said, leading Zoe down a rickety metal catwalk that cross over the gaping pit to another hallway in the wall to the right. Each step they took shook the catwalk, making it creak and groan under their weight.

“You sure this is safe?” Zoe asked.

“Yes, safe. Very safe.” Klihur said, almost a little annoyed.

“Right.” Zoe said. Even if she fell, she’d be fine. But there must be a better way to do this than to have this maze of catwalks twisting around each other, too.

Klihur led her down the hallway to another room with a large glass sphere sat in the middle of it. “Here.”

“I put ten billion mana into this?" Zoe asked.

Klihur nodded, and slammed the door shut, leaving Zoe alone in the dark room. The two torches that hung from the wall near the door cast a flickering light through the room that refracted through the glass sphere, creating an odd light show on the opposite side of the room.

Zoe shrugged and walked up to the sphere, trying to identify it. But nothing showed, was it something natural then? Or just not enchanted with Identify? If it was a permanent structure in a facility, was there any need for it to be identifiable? You could just have a manual somewhere instead, she supposed. Or some training videos for the new goblins, Zoe giggled to herself.

She placed her hand on the sphere, and pushed some mana into it, trying to feel its inner structure but there was nothing. Just a vast emptiness that put everything she’d ever enchanted to shame. Even that golem core that she’d filled with mana so many years ago for that enchanter she worked for seemed like little more than a puddle in comparison. What was his name again? Ken?

Zoe shrugged. Hopefully he was alright, maybe she’d try and find him again someday, see if he wanted to buy some more mana. It would be a trivial feat to fill anything he needed at this point, though his apprentice had been working on her mana regeneration too if Zoe recalled. How much mana did she have now, pursuing mana as her main goal?

An earthen chair formed behind Zoe and she sat down as she started pushing almost all of her mana into the sphere. Minutes passed, and she still couldn’t notice even a hint of what was happening inside the sphere, the bottomless well no more full than it was when she started. Then ten minutes, then twenty. And still nothing.

Was it holding the mana itself? Or was it transferring it somewhere else, similar to the game she’d played with Peter last time she was here? She tried focusing on the surroundings, to see if the incredible amount of mana she was pouring into it could be seen running through the floors or walls, but if it was, then she couldn’t notice it.

Maybe it was some system shenanigans? The mana ripped away to whatever dimension the system used for whatever it was doing? Or maybe the simplest solution was that the sphere was just an incredible feat of engineering and had a near endless capacity for her mana.

Zoe lost track of time as she focused on her mana exiting her hand and flooding into the large glass sphere until she noticed the faintest hint of something happening within it. Every bit of mana she could feel seemed to be intercepted by the smallest twist of space. Taken and sent somewhere else.

She tried pushing her mana into the sphere from different directions, tried spreading her mana out within the sphere just as it entered to get around it but nothing seemed to matter. Almost as soon as her mana entered the sphere, some small portion of the mana was spent to twist space just enough to rip the rest of her mana away, sending it somewhere else.

Where would it be going? To some battery, somewhere else in the facility? Maybe her theory was right and it was being ripped away to whatever dimension the system operated from? The warps in space didn’t reveal anything about where the mana was going, so she was about as clueless as before she noticed them.

But it made her curious about making such a thing herself. If she could create some sphere that would transport mana to a designated location, then she could in theory continue to power some enchantment at home that would be too costly for any of her friends back in Foizo.

What such an enchantment would be, she wasn’t sure. Some growth enchantment to improve Foizo’s farms? Or maybe just some battery to store mana for general use in the city? She’d have to see if the leadership at the Springs of Gir would be willing to share some of the details about how the sphere worked, maybe for some additional mana cost.

For that matter, were any of the other dungeons truly different? A productive dungeon helped them, but so did a lodestone dungeon. If she climbed up to the top of Moaning Point and spoke with the lich that spawned about paying it some mana, would it become friendly to her?

A case of theft: this story is not rightfully on Amazon; if you spot it, report the violation.

Or was that just a feature of the productive dungeons, since the monsters in it were already supposed to be friendly? She’d tried to invite the boss of Kliggig dungeon to dinner once and that failed, spectacularly. But she didn’t offer to give it mana, either.

Before she knew it, Klihur opened the door to her room and walked in. “You’re done.”

“Oh! I didn’t even realize. This is a fascinating thing, here.” Zoe said.

Klihur nodded, a somewhat confused feeling poking at Zoe’s Vampyric Empathy. She decided not to bother explaining, somebody else would have information on it. Maybe whoever was going to be giving them a tour — hopefully not the adorable but rather clueless seeming Klihur, she thought to herself.

“Please follow me.” Klihur said as he started walking back down the hallway towards the large pit full of criss-crossed narrow walkways. Zoe followed him all the way back to the room where Eliza and Lila were sitting on the bed, the room filled with feelings of anxiety and frustration.

“Are we finally going to get this tour?" Eliza said as Klihur entered.

Klihur nodded. “I will let boss know you have paid.”

“And then we get the tour?” Zoe asked.

Klihur nodded and shut the door.

“The damn thing’s locked, you know?" Eliza rattled the door knob, slamming the door against the metal latch with surprising force. ”We’re stuck here, unless we want to teleport out.“

“It’s fine, Eliza.” Lila said. “They seem nice.”

“Yeah, nice. By imprisoning us.” Eliza sighed as she fell down onto the bed.

“It’s fine. I saw something pretty neat out there on my walk, though.” Zoe said.

“What?” Eliza shot up.

“There was this really big cavern, with I dunno, thousands? Of the same metal hallways branching off of it. Narrow, kinda scary metal walkways crossed over the pit and connected each of the hallways to each other in a tangled mess. It’s really, really big.” Zoe said.

“Bigger than the springs?” Eliza asked.

“Way bigger. You could probably fit several of the entire dungeon into this pit. I wonder what it’s for?" Zoe asked.

“I have no idea. I thought we’d find something, but it sounds like there’s an entire underground city under here, for some reason?” Eliza suggested.

“Yeah. Lots more of these rooms, too. Jail cells? Some kind of weird inn? I’m not sure.” Zoe said.

“Maybe it’s an underground goblin city? They live down here, and work up on the surface?” Lila suggested.

“But why do they need so much space?" Eliza asked.

“Farms? They have food up there, it has to come from somewhere, right? I’ve never heard of them trading with nearby towns, so they must be self sufficient. I figured it would have just been created by the system, but maybe it’s all just actually farmed down here?” Zoe suggested.

“I guess. It seems like a lot of space though, for the few shops they actually have up there. They could get by with a much smaller footprint.” Eliza said.

“Inefficiency, maybe? Maybe they want people who happen to get down here to get lost and not find the important bits?” Zoe suggested.

“I suppose. Maybe they get visitors from other dungeons at times, too. Why wouldn’t they communicate with each other? Have each other over for dinner.” Eliiza chuckled.

“Maybe.” Zoe agreed.

Jeffrey arrived a short while later, unlatching the door and opening it for them. “Please, follow me. I’ll give you a tour of our facility. I must ask for your forgiveness, however, as there are some areas we simply must keep private. You wouldn’t like people poking around in your bedrooms either, I’m sure.” He smiled.

“That’s fine.” Zoe said. “What’s the purpose of all this down here, though? Why is it so big? Why are there so many of you? I thought it was just a hot springs, and this seems like… a lot more than that.”

Jeffrey nodded. “Do you ever see us trading with nearby cities for resources?"

“So you are producing every thing down here for the springs, then?” Eliza asked.

“Indeed we are.” Jeffrey answered, stepping onto the rickety metal walkway over the cavernous pit.

Eliza and Lila both paused to look around at the mess of metal sprawled across the pit, layered over each other like tangled mess of wire.

“You need all of this just to produce things for the springs?" Eliza asked. ”This seems so excessive, to me.“

“Yes, well much of it is for leisure. Gyms and restaurants and the like, and you’d be surprised at just how many things you need to keep the springs working. Every souvenir that is sold needs to be produced somewhere, and we can’t just go chop down trees from the surrounding forest or import wood from somewhere to make them. Metal needs to be created and formed into shape.

“And even the food is an incredible amount of space. The animals we need to house, food for all of the animals. Food to grow the food for the animals. You want hot water for the springs? The water must come from somewhere, it must be heated, it must be prepared properly.

Eventually, you’re left with this.“ Jeffrey gestured around the room. ”A jumbled mess, hobbled together to fit the need of the dungeon.“

“And every productive dungeon has something like this beneath it?" Zoe asked.

“I can’t speak to any other dungeon. But this is how the Springs of Gir are run. We’re entirely self sufficient, and we take a certain pride in that. Perhaps other dungeons rely more heavily on their denizens skills and mana for their purposes. I couldn’t say.” Jeffrey answered.

“Huh.” Eliza hummed. “I’m not sure what I was expected here, but it wasn’t this. And you’re so much more friendly than I had thought, too.”

Jeffrey chuckled. “Well, we’re a dungeon at the end of the day. You wouldn’t have been the first to force your way in here, and you wouldn’t have been the last. If we can do so on more friendly terms, in a way that benefits both of us? I suppose the boss sees no reason to not be friendly.”

“Do you think other dungeons would be likely to agree to a similar deal, if I offered it?" Zoe asked.

Jeffrey just continued walking in silence, leading them across the rickety metal walkway.

“Alright. So, where are we headed first?" Zoe asked.

“Right now, I’m taking you to our farms. I suppose that’s what you’d be most interested in.” Jeffrey said.

“Honestly, I’m most interested in whatever you’re using the mana for. And that sphere that I was using earlier to give you the mana, do you have more information on how it works? Where did all of that mana go, anyway?” Zoe asked.

“I would agree, what’s the purpose behind harvesting all of this mana?” Eliza agreed.

“That I cannot answer.” Jeffrey said.

“Can’t, or won’t?” Zoe asked.

“Can’t. I simply don’t know. We harvest mana, and that’s the extent of my knowledge. I’m not sure that anybody knows more than that here. Maybe the boss would but I couldn’t say for sure.” Jeffrey said.

“Can we meet the boss?" Eliza asked.

“She can.” Jeffrey said, pointing at Zoe.

“Me?" Zoe asked.

“Yes, you made the payment. If they want to meet the boss, they can make payments of their own.” Jeffrey replied.