First Undertale fic! Well, it's just planned to be a one-shot. Just an idea I had so, enjoy!

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"I kept my promise..."

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"Sans! Where's pa?!" The short skeleton looked down at the even shorter, but lankier, baby bones.

It had started as a normal day, maybe the only thing different was their father, leaving earlier, staying at his work for longer and coming home later.

"He'll be back soon, bro. I know he will." Stop lying to him... In truth, he had felt the magical connection holding the small family together shatter at one end. About an hour ago he had heard people outside pass by, speaking in hushed whispers. Through the blinds, he could make out the lot of them, staring at something in the distance... Something obviously alarming... It was the same direction their father went to work.

"Sans? It's getting late!" He patted his brother's cheekbone to grab his attention.

The young skeleton felt himself falter. He hoped he was wrong about something terrible... He couldn't look after himself and Papy.

"I'll wait a few more hours, he'll come back by then. When he comes, I'll wake you, okay? Bro?" He tilted his little brother's head to look him in the eye sockets.

Papyrus looked still unsure, wanting to make sure his father was safe. But half-heartedly nodded and allowed the older skeleton carry him off to his race-car bed. And as Sans read him his favorite bedtime story, reciting it without looking at the pages, due to him reading it countless times, Papyrus just wished Gaster was there at the moment. Though, soon enough, he was lulled into sleep.

Sans, came to find a royal guard at their front doorstep, seeing the child, the older monster gulped and stuttered. "I-is there a Mrs, of this house?"

"No, sir. Just me and my brother, and well, my father, Gaster. But he hasn't been home today..." He looked up at the guard, sighing and pulling out a slip, kneeling before the tiny skeleton. "I'm sorry, son... I'm sorry, to inform you of this. But one your father's projects... Backfired on him. There... Was no dust left." He quickly shut his mouth, deciding not to go on."

Sans felt chills pass through his very soul. Using his teeth to rip open the letter, scanning the short paragraphs, pretty much a more detailed explanation of what had happened, some words he couldn't understand... There was one that was frequent, and caught his eye...

Passing, death, etc.

Sans clutched the letter as tears fell from his sockets, the tiny white lights if his pupils growing dark in his distress and confusion.

"Papy...?" Sans opened the door to the baby bones room.

The tiny skeleton shot up, bouncing out of his bed. "Is pa here?!" He darted past his brother.

"Pap, no...!" He was too late as the tyke was met face to face with their living room, full of Gaster's co-workers, friends, and even the royal family.

The little one was a tad bit confused at the grim looks but wandered through the group. "Pa? Pa?" He called out, silencing the whole room, the air seemed even chillier.

The king, the big softie he was, bent down to get closer to the small skeleton. "Child... I am sorry one has to bear this burden at such a tender age..." But papyrus was even more confused. "But, where's daddy?" Asgore gently tightened his grip. "I'm sorry. I thought a guard came by and informed you... Your father..." He took off his crown, bowing his head. "Has passed away."

Papyrus looked a little startled, but growing more and more shaky. He turned his head and gazed at his brother. "Sans?" The rest of the room either looked at the two skeletons or at the ground.

"Papy-"

"You said he would come back?" He wailed. "Where is he? Is this another one of your stupid jokes?" The small thing broke from Asgore's light grip and darted out the front door, met with even more grim looking monsters. He continued on towards the path he knew Gaster walked, just as if to see a glance of his father. "Daddy?"

Sans broke into a sprint after his baby bro. It took a little more than running to catch up with the determined skeleton, teleporting in front of him, he gripped his shoulders.

"Where is he? Where's pa?!" More questions were asked like this, met with silence everytime.

"Sans... You promised!"

"He's dead! Okay, Paps?! D-E-A-D! I don't know why this happened but it did and I can't promise things like this won't happen!" Sans snapped, all of his young confusion and sadness broke out. "He's gone, and he isn't coming back!"

His eye glowed a vibrant blue and he held his head as tears streamed down his face. "h-he's gone..."

One look at his brothers face made him almost fall apart, right then and there.

A waterfall cascading from the tyke's sockets. Rubbing away one thick stream, only to be replaced. He wailed, liquid dripping against his little shirt and long red scarf.

"B-but, I-...y-you..." The small one spluttered.

Sans took a moment, staring at his brother, hating the look of sadness of the skull. Despising it.

"Paps...I'm sorry. I just... It's going to take awhile. But I'll protect you."

"But... P-pa?"

"We'll see him again someday. But I need you to believe in me." Sans held his arms open. "We can do this together. But I need you... Please. And I promise I won't get hurt or leave you."

Papyrus, wiped his tears away. Staring at the offer before stumbling forwards.

"I promise I won't leave you either... And I believe you..."

...

"I believe in you... Human. I tru- ACK!"

The skull toppled from the limp body. Landing in the snow, watching as it's own vessel vanished into dust, before staring up at the human, smiling his natural smile. Even as the THING put their foot on their face and crunched Papyrus' skull underfoot before continuing on through the snow.

Once they were gone, a figure darted across the white space, sliding next to where piles of dust were getting blown away in the wind. He scrambled and tried to hold the dust together, but to no avail.

"dirty...dirty brother killer!" The skeleton snapped, ripping off his hood and shouting to the sky.

Red

Something red

Sans paused, staring at the scarf. The only thing left of his brother. Of his little Papy.

Trembling bones reached out and tabbed the soft fabric, holding onto it like it held him in reality. An anchor.

"I promised I wouldn't get hurt. I wouldn't leave you. I believed in you... So why didn't you?"

"I kept my promise... So why didn't you keep yours?"