Once you're all in the car and Sans has proven himself a surprisingly decent driver, you realize you don't actually know where you're going. So you look to Gaster- who, despite being the tallest person of the five of you in the vehicle, has somehow managed to fit himself into the middle back seat (Papyrus is to his right, you to his left, and Alphys in the front passenger seat)- and ask, "Hey, Gaster? Where are we going?"

When he looks down at you, it's with a childish grin of excitement, and you can't decide if that's because he's excited to get wherever you're going, or because he has achieved some personal goal of somehow defying the laws of reality to fit a seven-foot-tall monster in the middle car seat. Regardless, it's with a bright expression that he answers. "To the CORE! The first one, I mean. In Hotland."

"...Why?"

He starts to speak, then pauses, one hand rising thoughtfully to his chin. "... A few reasons, actually. For one thing, I haven't been there in a long time. For another, there are a few structural things I want to remind myself about for building the new CORE. and third, Alphys is going to be helping us build, but she doesn't know how the CORE works, really, and while it's true the new CORE will be powered differently, what with it being hydropower based rather than geothermal, but it'll still be good for her to learn."

"Oh," you say.

"But most importantly," Gaster continues, flashing a smile towards Papyrus, "Papyrus has never been to the CORE before, and has never had the opportunity to experience one of the greatest puzzle systems in the whole history of monsterkind."

"you narcissist," Sans says from the front seat.

"Well, it's true," comes the self-assured reply. "And besides, Sans, you had a hand in the puzzle design yourself. So you should be taking that as a compliment."

Papyrus gets excited at that. "Sans, you helped design the CORE puzzles?"

Gaster smiles proudly. "He was in charge of designing them, if I remember correctly."

But Sans scoffs. "i didn't hardly do anything. just came up with a few basic concepts before you... took over."

A hush seems to fall on the tallest skeleton as some understanding passes over him. There's something left unsaid between the father and son, something that sobers the grin that had been sitting on Gaster's face.

Finally, the Royal Scientist murmurs, "Well, they were good concepts."

He offers the sentence almost, it seems, as an apology.

The car remains quiet for a while, but eventually, some idle chitchat picks up again.

And then Sans is parking the car at the entrance to the Underground. You all tumble out, dusting yourselves off from the ride, and Sans tosses the car keys back to Papyrus. Then, Gaster in the lead, you all walk into the Underground.

It's eerie how quiet it is. You remember the first time- and subsequent times- you walked through the path on the wall around New Home. Except for That-One-Time-You-Don't-Think-About, you were always able to hear the monsters. Not just the ones that came up and talked to you, but the ones living below, too, in the city. The constant murmur of life. But now...

It's silent. The footsteps of your small party echo throughout the vast, empty caverns, and you can hear water rushing somewhere in the distance, but other than that...

Getting to the CORE is even more strange. It was always so loud, so busy before, the hum of fans and the clanging of machinery, almost like it was making its own song, with a brilliant lights show to match. But now it's dark and quiet; there's no blinking lights or whirring, ticking traps, not even a hint of that pale, Magic fog that has clung like glitter to the air.

When the five of you actually get into the CORE, Gaster steps ahead, walking out slowly onto the catwalk. You move to follow, but Sans stops you with an arm across your chest. You look at him.

"just give him a minute, frisk."

You nod, and look back to Gaster.

Even at the distance, even only seeing his back, he seems... different. Not the high-energy, excited, childish monster he had been mere moments ago. He seems quieter. More solemn. Almost as if the flashing lights and pulsing rhythm of the CORE were the Magic and beat of his own Soul. As if the CORE being dark and dead like this is his own death.

He walks slowly, one hand out, fingertips just brushing the top of the blue guardrail. It almost seems as if he's in another time, another place. And you can imagine it. You can imagine him walking down that catwalk, coat billowing in the mist as it's filled with the Magic from below, his palms flickering with Magic, the glow of which rivaled by the flashing lights, each footfall matching the pulse from deep within, a song of his own, far under the earth, one that only he hears, in the heart of his creation.

Eventually, Gaster leads the group of you forward, far into the CORE. It's slow going, though. He stops frequently, running his hands over the spots where the blue tile paneling has been peeled away to reveal the pinkish insulation beneath, or stopping to touch a large crack in the wall, all with a look almost of... anguish.

"he likes his creations to last," Sans murmurs quietly to you on your questioning look. "and the core's only been around for a couple decades, but its taken a real beating."

Eventually, as you come to the main elevator, the group splits. Papyrus wants to stay on the upper level of the CORE to try to work through the puzzles, once Gaster's got the power back on, and Sans is staying with him, while Gaster and Alphys delve deeper into the massive machine. Having been through the puzzles before, you decide to go with Gaster and Alphys, and step alongside them into the elevator. Gaster hits a few buttons, and suddenly, the metal box launches downwards.

When the elevator doors open, you feel as if you've stepped into an entirely different world. It's dark, for one thing, and you're infinitely relieved as Gaster pulls a flashlight out of his coat pocket. And it's massive, too. When Gaster shines the light upwards, you see the beam pass through the grated floors of many other catwalks far above, but as far as you can tell, it reaches no ceiling.

And far below, you can see great pools of magma, huge turbine fans sitting half submerged in the pools, turning lazily with the slow current of the molten rock.

As Gaster leads the way forward, he begins explaining in a hushed tone to Alphys how the CORE works, pointing out different features. But you're not really paying attention. For one thing, most of what he's saying makes no sense to you, and for another, you're far too distracted looking around- it's dark, but there's enough light from Gaster's flashlight and the magma below that you can make out the sheer enormity of the place. There's machinery everywhere, catwalks crisscrossing back and forth and up and down, elevator shafts punctuating the vertical space, accompanied by supports and scaffolding, all of which being laced through by wires and tubes and air ducts and Annoying Dog knows what else.

Even dark and silent as it is, even with your limited view, the whole thing still speaks volumes to Gaster's ingenuity. You can't imagine what sort of thought process went on behind this, the kind of wild and skill he must have had to put into it.

Eventually, Gaster leads you to what you can only assume is the center of the CORE. Gaster does... something, and a few lights come on, enough for you to see that you're in some sort of large, round control room, filled with control panels and monitors and switches and buttons. The wall in front of you is dominated by a huge bay window, leading into the true heart of the CORE. It's a massive octagonal room, going up and down too far for you to see. The walls are white, made of some seamless material, but you can faintly see some sort of pattern etched across the surface. There are cables, too, but they're thin, tiny, gossamer strands running all across the room from nodes on the walls, creating some sort of massive weblike network.

Once the three of you are in the room, Gaster closes the door behind you, and you hear a hiss of pneumatics and a hollow clang! that Gaster tells you is the blast door sealing. Before you can wonder why there might need to be a blast door, Gaster is ushering you and Alphys over to the side of the room and telling you both not to touch anything. Then he steps over to the center of the room.

You had been too captured earlier with the interior of the CORE's center to pay attention earlier, but now, looking at the control room, you see it's almost like there's a whole nother control room set in the middle of it. Not a new room, really, with walls and all, but inside the main bubble of the control room is another set of control panels and whatnot arranged in a circle, and it's here that Gaster stands.

For a moment, he just looks over all the machinery, out to the huge room through the window.

Then you hear him murmur, "Right. Let's see if you still work the way I made you to."

Then he sets his hands agains the control panel.

§

A/N

Man, I really hate having gotten my wisdom teeth pulled. My jaw aches, my cheeks are puffy, I can feel the stitches in my gums, and the pain medications just make me super dizzy.

Oh well, on the bright side, at least I got to sleep for half the day.

Anyway, thanks for reading, and I hope you enjoyed it! Comments and votes are my Favorite Things, and every notification I get makes my day!