It was October 31th. Autumn was still around, but the cold winds of winter were noticeable. Although it probably wasn't important in the Underground, what really was important was the festivity humans and monsters separately celebrated on this day, almost all night long.
It was Halloween.
And boy, was the Underground excited. The festivity in which they celebrated how they shoo'd a human ghost was some people personal's favorite.
Including some little skeleton toddlers.
"HEY! HEY! HEY SANS!" The smaller brother, probably no older than 5 years old, shouted to his coated sibling which name apparently was Sans.
"yeah, paps?" Sans' low and tired voice was heard saying. Although he looked like he didn't have any excitement towards Halloween, if you knew Sans, you'd know that is quite the opposite.
"AREN'T YOU EXCITED FOR HALLOWEEN? AREN'T YOU? AREN'T YOU?! AREN'T YOU?!" The smaller brother known as Papyrus shouted, with his voice with full adrenaline. Without the younger sibling's shouting and happiness, Snowdin wouldn't be the same.
"heck yeah, i am bro. let's let them have it." Sans said with his quiet, yet excited voice.
"YEAH!" Papyrus shouted, loud enough for anyone to hear it "BY THE WAY, WHERE'S YOUR COSTUME?" Papyrus said, a little more silently.
"right here." Sans said, pointing at himself obliviously, like it was the most obvious thing in the world.
"WHERE?! I DON'T SEE IT!" Papyrus shouted in utter confusion and disbelief. Sans' grin widened which, for Papyrus, was never a good sign. "OH NO, YOU AREN'T-"
"here, look." He pulled out a red marker from his coat's right pocket and wrote the words 'sans' in said font lazily.
"SANS! THAT'S NOT A COSTUME! YOU JUST WROTE YOUR NAME ON YOUR FOREHEAD, YOU LAZYBONES!" Papyrus yelled, and his googly eyes made their entrance.
Sans hold back a snicker at his younger brother's eyes "c'mon bro, what's so wrong about it?" Sans said, once again, obliviously.
The red-scarfed boy was about to explode "SANS! YOU KNOW WHAT I'M TALKING ABOUT!" Papyrus' face was now red.
"no, i don't."
"YES. YES YOU DO!"
"no, really, i don't."
"GAH!" Papyrus threw their tiny arms to the air (not literally) giving up. "FINE, HAVE IT YOUR WAY. IT'S ALREADY TIME FOR TRICK AND TREATING ANYWAY." Papyrus literally bursted out of the door faster than lightning— no, faster than literal tachyon particles, as Sans would say, and going to the right of the house, as if he was running for his life. Sans could swear he almost saw the snow that he stepped on melting.
"ok, then." The 'lazybones' said as he entered to the house
Papyrus kept running until he found a house and...Sans on the door?! "WHAT?!" He said, almost about to crash from the surprise.
"sup bro?" Sans said, smirking on the inside (and outside by default).
"SANS?!" They looked to the direction they had parted on "HOW DID YOU GET HERE?!"
"well, bro..."Sans started, preparing his hands.
"SANS...NO." Papyrus said, and almost shouted, guessing what he was about to do.
"it's just..." Sans said, putting his palms together above his head.
"SANS, NO! PLEASE DON'T DO THIS— ANYTHING BUT THIS, I BEG OF YOU!" Papyrus literally yelled while he kneeled down, hands together with his head looking down as if Sans was his king.
"...magic." He did a blue arc resembling a rainbow with the former.
"SANS!" Papyrus yelled at the top of his lungs. This scream was louder than 180 dBs, meaning that it was louder than a freaking rocket launch. Basically all the underground could hear it. Everyone, including the king, the queen. Everyone and everything. Every Echo Flower would have this scream repeated.
Sans was glad he didn't have ears. Who knew what would've happened if he had, would he have exploded? Maybe. Probably. Okay, totally.
"# $&!" Papyrus shouted to Sans at a normal angry Papyrus level "geez what- bro, what are you saying? hash, at sign, dollar and ampersand?" Sans would find this funny, if fourth wall breaks weren't so usual this day. It was still funny, though.
"okay, okay bro." Sans hugged Papyrus and patted him on the back "there, there...even if i'm in a, hehe, 'bad costume' ,even if i'm doing a lot of 'bad puns', this halloween is still going to be epic. now, are you ready?" Sans said wisely, as a good, but not always seen, big brother figure.
"Yes..." Papyrus' response came as a low mumble while they looked down.
"what? i didn't hear you well." Sans said putting a hand on his non-existant ear and got it closer to Papyrus.
"YES." Papyrus said in return.
"louder!" Sans said, using the, as he calls them, cursed exclamations.
"YES!" Papyrus shouted on return.
"nice, let's get going then." ." he said bluntly, as he started walking to the house that was just next to them while he was holding Papyrus' tiny hand.
Sans glanced at Papyrus' costume and admired more its details. It was a Santa costume that was obviously handmade by Sans. This was noted on the lazy sticked wool on the hat and some of the costume was beggining to get unsticked. Even so, Papyrus cherished it like it was a treasure as it was one of his first costumes. Just like his brother.
Sans grinned happily at Papyrus "you're so cool bro."
Papyrus looked at him with stars on his eyes and a big smile.
"I KNOW!"
Even if he annoyed Papyrus, or Papyrus annoyed him, they were still brothers and loved each other very much.
They were the best of brothers.