It was on the eve of halloween, that Papyrus had a really great idea. He'd pitched it to Frisk, who was hesitant, but agreed regardless. As the night grew dark in Snowdin, Papyrus and Frisk set to work. Sans had long since fallen asleep, leaving Papyrus and Frisk with the whole house to themselves. Papyrus whispered, though considering how Sans usually slept like a log he probably didn't need to, to Frisk. The plan was simple. They'd dress up in their halloween costumes, and wake Sans up with a scare. Just a little harmless joke, since Sans wasn't able to join them for Halloween celebrations the following day.

Papyrus had a very simple costume, one he wore every year, a ghost outfit. Frisk wondered if ghosts were all that spooky, considering how timid and kind Napstablook was. Frisk's outfit was improvised on the spot. A blunt toy knife and some messy hair. Their skin had also been lightened a few shades with white foundation. Papyrus thought it was a little too simple, but Frisk already seemed uneasy with this much effort put into the prank. Papyrus stood in the loungeroom, inspecting himself in a hand mirror, when Frisk tapped on his shoulder. Papyrus turned around to see Frisk looking up at him, a frown across their features.

"What's up, human?"

"[Is this a good idea?]" Frisk signed.

"Of course it is! I, the great Papyru-" Frisk winced as Papyrus' voice grew loud. They waved their hand quickly to grab his attention, it seemed to do the trick.

"[It just...seems a little mean.]" Frisk signed, before breathing out a sigh.

"Well..." Papyrus visibly struggled to keep away a disappointed appearance, assuming a neutral facade. "If you don't want to do it, then that's okay!"
Frisk paused for a few moments, before shaking their head. "[It's okay. I changed my mind.]" They punctuated their sentence with a thumbs up.

Papyrus couldn't hide the smile on his face. "This is going to be so awesome."

Frisk grimaced slightly, looking down to the knife in their hands. It was definitely, visibly fake, dark grey in colour and everything, but still...
No, Papyrus looks too excited they thought to themselves. So it's going to happen. I just hope Sans takes it well...

Papyrus' gaze washed over Frisk's outfit one more time. "That look...is quite unsettling on you, Human. Let's get changed right afterwards, okay?" Frisk nodded in agreement.

"Mmmhm."

Papyrus turned to the stairs, signaling it was time to act out their little plan. Papyrus didn't seem to have a care in the world as he climbed the stairs. He reached behind a painting on the top floor to find a key, which he used to gently unlock Sans' door. Frisk tapped quietly along the floor after him, standing next to him at the door. Papyrus practically vibrated with excitement. Silence washed over the two of them for a few moments, only the soft hum of the fridge to be heard in the house, occasionally accented by the soft snores of Sans.

Frisk looked back at Papyrus one more time, not bothering to sign to him. They didn't think it'd change his mind at this point, anyway.
"Okay human!" Papyrus whispered, but in a voice loud enough to just be a regular speaking voice. "Three...Two...One!"

The two burst through the door together, Frisk somehow stumbling further in than Papyrus in the confusion. Papyrus hit the light switch, illuminating the room. At the same time, he called out a hearty 'boo!', which was enough to wake Sans up from his sleep. Sans sat up in bed immediately, eye sockets squinting in the sudden light. He held his arm over his face, looking over to the door.

"Papyrus?" he probed, voice thick with confusion. His line of sight drifted slightly lower to Frisk's level, and he froze. Magic flared up in his eye, time stopping for a moment in Frisk's perception. As the two made eye contact, they noticed something deeper than just shock, something more like fear. It occurred to Frisk very briefly that Sans was afraid of them. They felt the cool breath of magic from Sans flow over them. Sans took one step out of bed and as he did, he swung Frisk across the room with his magic. Papyrus launched forward immediately, reaching out to his brother with his hand.

Air whipped past Frisk's head, and they saw the wall coming for them. "Sans, stop!" Papyrus yelped, Sans' magic dissipating instantly, causing Frisk to hit the wall much slower than Sans had intended. They still made a solid thud as they hit the plaster. They coughed on impact and for a few moments after, scrambling to a sitting position against the wall.

Somewhere in the confusion, Frisk had dropped the toy knife and was now signing 'sorry' with one hand, the other pressed up against the wall for support. Papyrus stood infront of Sans, holding both his shoulders in his hands. "They didn't mean it Sans, please!"

In his groggy state, Sans' line of sight flickered from his brother, to Frisk, to the knife on the floor. It took a few seconds for him to put together what had just happened, but when he did, his face dropped into sheer regret. Frisk's heart beat madly in their chest, panting heavily from the sudden rush of adrenaline.

Meanwhile, Papyrus continued to shout out apologies to his brother. "It was all my idea, we didn't mean anything by it, honest...Sans..." Papyrus' voice trailed off, and soon the only noise in the room was the frightened breathing of Sans and Frisk, who both looked at each other with a mix of confusion and silent apologies.

Sans was the first of the two to make any movements. He glanced down at his hands, then just short of Frisk. "I'm sorry kid."

Frisk forced a smile back at him. They nodded, returning Sans' sentiment. Sans then turned to Papyrus. "I...I have to go." He stepped back out of Papyrus' grip, then pushed past him to run out the door. Before Frisk or Papyrus could do anything, he was gone.

Papyrus stood still for a few seconds, bones locked in place, before remembering where he was and rushing over to help Frisk. "Are you okay? I should have listened to you..."
Frisk's breathing had calmed somewhat, and they pushed a smile onto their face. They pat Papyrus' cheekbones softly, offering them a thumbs up. "[It's ok.]"

Frisk stood up, shakily at first, brushing off their clothes. "[We should look for him.]" Papyrus agreed, and the two got changed quickly before heading outside to look for Sans. They decided to look in Grillby's first, and to their surprise, Sans was actually there. Neither of them thought it would actually be that easy, so they were surprised to see his slumped form at the bar, just his hoodie showing with the hood pulled over his skull.

Frisk stepped forward first, calling out to the shorter skeleton. "Sans!" Their voice crackled from little use but it caught Sans' attention, who spun around to meet the gaze of Frisk.

"Hey kid," he rubbed the back of his neck nervously. "Not often I hear your voice, somethin' important happening?"

Frisk nodded. Some of the patrons noticed Frisk speaking and looked surprised, their eyebrows (or other facial features) raising in shock. "Sans, please."

Sans' smile dropped into a grimace. "Not here, okay? I'll walk you two home." Sans slid off the bar stool and lead the two outside, where the cold air smacked the group in the face. Sans walked a little faster than usual, glancing back every now and then to check on the two.

Once inside safely, Sans sat down the couch. Frisk sat next to him, settling into the cushions with a soft pap. Papyrus sat on the floor. An uncomfortable, thick silence hung over the group, and Frisk felt nervousness crawling up their back.

"We're sorry we scared you." Frisk suddenly chirped out. Their eyes reflected the regret they felt piling up in their chest.

"No." Sans insisted, almost too quickly, as if he was prepared to disagree. "It was a harmless prank, I know you two like to have fun, I didn't have tibia wet blanket about it." Papyrus' nervous frown settled into an annoyed grimace, but he didn't say anything.

"[Don't do that.]"

"Do what, kid?" Sweat beaded on his skull, and he avoided Frisk's eyes. "This reminds me of the-"

Frisk's subtle frown turned into an agitated one. "[Stop that! Stop avoiding talking about things. It's making everyone uncomfortable.]"

Sans sighed, wiping off his brow bone. "I don't know what I'm avoiding, kid-"

"[Why were you scared of me?]"

Frisk's question hung in the air for a while. Sans stared at their hands, motionless, waiting for an answer. His grimace grew more strained, and he found it hard to fight the urge to just run away.

"Afraid? Of you, kid? Never. Look at'cha, you're, you're,"

"[You're not looking at me.]"

Sans looked confused for a moment.

"[You're not looking at me at all. You've been avoiding my eyes this whole time. You keep looking at Papyrus, but not long enough for him to notice. Why?"
Papyrus, who had sat still for possibly the longest time in his entire life, finally shifted nervously. He adjusted the scarf on his neck.

"Kid, listen, it's okay. Nothing's going on." Sans stood up to leave the room, taking a few steps past Papyrus. Papyrus looked like he wanted to reach out to his brother, but couldn't move far enough to do it. Frisk stood up after him, calling out to him in a firm voice.

"Stop!"

Sans visibly shuddered. He refused to turn, but his face tilted slightly in their direction. "Are you sure...you won't leave me alone about this, huh?" Neither Frisk nor Papyrus made any attempt to reply, their silence was enough of a reply. Sans slumped, letting out a breath he didn't know he was holding in. "A-Alright. I'll...I'll tell you."
Frisk and Papyrus visibly relaxed, until Sans turned around and the look of timidness and fright in his eye sockets caused them to tense up again.

"I have, uh, nightmares...Well, they're not always when I'm asleep, but," he stumbled over his words, hands shaking just slightly. "They make me...uneasy...nervous..."

"[Is Papyrus in them?]" Frisk asked.

"S-Sometimes."

"[Am I in them?]"

Sans froze. Every joint in his body locked up and sweat poured down his forehead. His eyes darted around the room, but avoided Frisk. He couldn't bring himself to speak.
Frisk had an idea of what that meant. The vague inkling feeling they got from the other child, a presence they had felt for a long time, gave them an idea of it. "It's okay, now. It's okay Sans."

Papyrus didn't seem to follow the atmosphere, but knew enough to know when to speak. He looked up to his brother, and offered him a patient smile. "Do you think...I could hug you, brother?"

Sans nodded, ever so slightly, and Papyrus shot up, scooping Sans up in his arms. Sans wrapped his arms around his brother's shoulders and shook softly from holding back sobs. Frisk approached slowly and patted down Sans' spine as huge globs of tears rolled formed on Papyrus' scarf that Sans had buried his head in. The three stayed like that for what felt like ages, Papyrus and Frisk comforting Sans and Sans wordlessly venting his emotions into his brother's shoulder. It made Papyrus uneasy to see Sans crying, but he mostly worried about comforting him when his brother needed him. Sans was always doing so much for him, after all.

After a while, Sans' sobs died down, and he stood back up from the small cuddle pile the three had found themselves in. He excused himself to go to the kitchen so he could wash off his face, and returned shortly, looking flustered over his outburst.

"Thank you. I shouldn't have made such a fuss-"

"Sans, you are allowed to cry! All the time! Anytime! Don't apologise! Of course, I'd like it if you weren't crying all the time, but..."

"[Papyrus is right. Don't worry about it. We don't mind.]"

Sans' smile returned, a genuine, relaxed smile. He didn't need to voice any more thankyous, it was obvious from his expression and the way he gazed at the two of them.

"[Do you want to have a sleepover in the loungeroom tonight?]" Frisk offered, pointing to the lounge.

"I'd like that, kid. I might not have the guts to fall asleep on my own tonight, after all."

"SANS!" Papyrus yelped.

Sans and Frisk giggled together, before setting off to make their beds on the couch and floor respectively. Sans slept well that night, free of nightmares.