Chainsmoker [ Gaster!Sans x Reader ]

8. Howling Ghosts

There it was.

It was the place that you seemed to have quite literally grown up in, the house where you had spent many hours with Sans and Papyrus. It was the last place in the entirety of the Underground that brought joy to you despite the resets. Because here it had been where you had given Papyrus his first actual cooking lesson. Here you and Sans had...

(Let's just leave it up to the reader's imagination.)

The photo of G was now just another forgotten memory in your mind, another attempt to block out the truth of the havoc you had reaped across the Underground. You had slaughtered them all, and there was no hiding from it.

Pots of spaghetti were thrown across the house at random. You had become too impatient waiting for Papyrus, you had dragged the skeleton out of his home to slaughter him.

G said nothing, only eyeing the ruined home warily as you sat down on the couch. Carefully you reached into the cracks and crevices, pulling out a handful of change, just as you had done so many timelines before. On the table in front of you was a seemingly abandoned chemistry joke book.

It had been one aspect that you had never asked Sans, his fascination with science. You often wondered if he had once been an assistant to the Royal Scientist Gaster, which would explain his vast knowledge of chemistry and the hidden lab behind his house.

"What did the covalent bond say to ionic bond?" you asked, flipping to a random page.

"'You should really learn how to share,'" G replied flatly, lost in thought. He was already beginning to walk upstairs, lost in memories. "It's strange," he murmured, just loud enough for you to make out his words. "It's strange to have the memories of two. I remember being Sans, being in this house with Papyrus for as long as we could remember."

He paused for a moment. "But I also remember being Gaster, working for countless nights on experiments that were long past their prime." He chuckled to himself. "I remember raising myself."

He opened the door to Sans' room, you following in after him. You smiled lightly. Though other things in the Underground had been ravaged by time, this was the one thing that somehow managed to stay the same. In the corner of his room was the iconic self-sustained tornado of trash.

"Nothing has changed," he sighed, eyeing the unmade bed. There were obvious signs of how much Sans had given up on trying to do anything, the molded plates of food left uneaten, to-do lists crumpled in the trash can...

You walked solemnly to Sans' closet and carefully opened it, as if you were afraid that the comedian would suddenly jump out, ready to kill you at a moment's notice. Your fingers wrapped around a dusted blue jacket, stuffed carelessly into a corner, long since forgotten. You brought it to your face, allowing the scent to overwhelm you. Even after all these centuries, it still carried the familiar smell of butterscotch and ketchup, a combination that was revolting to almost everyone with an inch of sanity.

But you weren't exactly the poster kid of sanity.

"You okay kiddo?" G asked, attempting to catch a glimpse of what you were holding.

"I'm fine," you replied quickly, shoving the jacket back into the closet, shutting the door behind you.

"I don't want to stay anymore," you whispered. Already you were beginning to notice the details you had overlooked when you first entered the room, claw marks on the floors, crumpled up suicide notes scattered at random.

And the dust.

You walked over to Sans' overturned bedstand, picking up a photo that had been cast aside. It was a photo taken from one of your very first timelines, the one where you had made it to the Surface and freed monsterkind. Papyrus stood in the background, his arms wrapped around you and Sans. You were looking directly at the camera, Sans staring tag the ground, the hints of a light-blue blush on his cheekbones. You frowned for a moment. Were skeletons capable of blushing? It had been ages since you had seen the comedian smile.

You brushed your thumb against the top right corner where in the smallest print, you could make out Sans' handwriting. Look what you've done to us, was scrawled across the top. You bit the bottom of your lip and flung the photo across the room, wincing as it collided with the wall, the already-broken frame shattering into smaller pieces.

The picture floated to the ground, your smiling face staring back at you. You felt bile rise in the back of your throat, how much you had ruined everything! You had destroyed the very fabrics of what you called family. It was enough that you had murdered your first one, now only to turn on the only living things that would probably ever accept you?

With a guttural cry, you attempted to fling yourself at the photo, determined to erase the evidence of the sadistic so called "happy-ending" that you had lived through, destroyed.

You break everything you touch.

"[Y/N] that's enough!" G shouted and you suddenly found yourself floating in mid-air, surrounded by a faint light-grey aura. "All of this, it stops here." He was looking you straight in the eyes, resembling the hatred Sans had felt for you during all those genocide runs in every single way.

"What you did, the past, you can't change that. But here, now, it's your chance to fix things, make everything better." He inhaled sharply before continuing. "I lied before. I'm old, very, very old. This dead world, it's like a waiting room for the human souls that are trapped in the Underground. Every human that falls down here goes through so many resets before the entire slate wipes clean and they end up here in this twisted timeline.

"I don't know why I look the way I do, and I don't know how, either. But every human that's fallen, I've made the same journey with them, walked them through the Underground until they reach the Core, where they are able to jumpstart the world again."

"And the cycle continues," you interrupted, shaking your head. "Yeah, I know - "

"You don't know!" G snapped. "The cycle ends for that human, and another one takes its place. All I know is that when a human restarts the Core, there's another soul that joins the ranks of Asgore's collection."

"So I die," you nodded once. For the first time in a very long time, you truly felt at peace. Death, it had been something you had longed for for so long, wanting a permanent end to this damned cycle you had been thrown into.

"You're the seventh human soul," G said softly. "If you leave, you'll be able to have a life on the Surface. You'll - "

"I don't want to," you replied flatly. "I know how my story ends. It ends with my friends never aging, watching as I decay before their eyes. I can't... I won't do that to them again. I'm staying."

This took him by surprise. G gently shifted the magic, allowing you to float slowly over Sans' bed before disappearing, allowing you to have control over yourself once more. "You don't understand," he whispered, not making eye contact with you. "Restarting the timeline, it's something you have to do."

"So I'll restart it," you nodded, a plan forming in your head. "But I won't allow myself to die. Because that's what has to happen, isn't it? After the timeline resets, the human has to die in order for their soul to move back to their original world."

G nodded once and for the first time he looked up at you, excitement in his eyes. For the first time, he wouldn't be alone.

"I'm here to stay."