Undertale {Sans X Reader}

Keeping a Secret

I finally made my way back to Snowdin where Sans was waiting. All my tears were gone, but I felt more as I had to lie to the person I love the most.

Sans was leaning on the side of the entrance to the Waterfall. He looked at me and smiled, but it soon faded when he noticed his brother was nowhere in sight. I got closer to him.

When I finally approached Sans, he said "where's my brother?"

"He told me to tell you he is recalibrating his traps so when whatever that thing is comes, they will be harder."

"no. we need to get him now."

"Sans, don't you trust your brother?"

Sans stopped. He looked down and some tears threatened to spill.

"its just . . . i've seen so many timelines where he dies. i only want him safe." He looked up at me.

"i believe you, let's go."

I grabbed his hand and we walked through the Waterfall.

-----

We arrived in this place called Hotland where most of the monsters were being loaded on a single elevator and sent to a place called the Core.

Alphys and Undyne were near the elevator that just sent the last load to the Core. They both looked at us.

"Did you ever find Pap?" Undyne asked, very worried.

"yeah, he's just messing with his puzzles; making them harder."

"Alright. As long as he knows what he's doing."

"L-let's g-go." Alphys stuttered.

We all got on the last elevator that just came back and let it take up to the Core, ever so slowly.

"where's mettaton?" Sans asked.

"L-leading monsters t-to the k-king." Alphys replied.

We got off the elevator and walked to this place called MTT Resort. It really just looked like a big hotel with Mettaton's face on it.

We walked through to a door on the other side of the hotel that CORE.

About halfway there, when I wasn't paying attention to where we are, I leaned my head on Sans's shoulder, tears on the verge. He noticed this.

"what's wrong, kid?" He asked.

"I'm just . . . scared." I looked into his eyes, a couple tears falling. "Frisk has never been known to hurt anyone; no human or monster. There has to be something wrong with him, I just don't know what it is."

"yeah, there may be. we just don't know."

"Yeah."

Sans dried my tears with his hand and I held him closer, which he didn't mind.

We finally arrived at this long corridor. Alphys and Undyne went on ahead to make sure all the monsters are safe. I went with them while Sans stood in the corridor.

I walked over to Alphys when we were done checking everyone.

"Hey Al." I said.

"Hello y-y/n."

We stood in silence till I had enough courage to ask her what was on my mind.

"As long as you've know Frisk, would you think they would ever kill?"

Alphys looked suprised when I asked her this, but she thought anyways.

"No. Frisk was kind a gentle to all monsters. He did promise to come back, but I was not expecting something like this. I'm honestly scared, like everyone else."

"Me too, Alphys."

I leaned over and gave the scared little creature a hug. She held me tight then let go, to go and talk with Undyne.

I noticed Sans must've been out in that corridor. I walked out the door that led there to see Sans shut his flip phone and look at me, a look of disappointment.

I was confused. "Is something wrong, Sans?"

He moved his head to his right, telling me to come closer. I became even more worried.

I came over to him and looked into his eyes.

"where is he?" He asked. I felt a huge wave of guilt hit my then and there.

"What?" I asked, as if I didn't know what Sans was talking about.

Sans took a deep breath. "pap. you know something i don't; i can see it in your eyes."

I looked down and started crying.

"y/n, please don't keep secrets from me." Sans put a hand on my cheek and I cried louder.

"I-I can't!" I said, shocking him.

"why? it's about papyrus-my own kin! i have to know! please . . ."

"Sans, I swore to him! I can't!"

"please . . . i'm worried sick."

I pulled him into a hug and cried faster, the image of Papyrus turning to dust fresh in my mind. Sans stroked my hair and I held him tight, not ever wanting to let go.

We then heard footsteps, faint, but still there. Sans pulled me back gently and looked around.

"go hide."

"No!"

"whoever that is, i don't want you hurt. please."

I sighed and ran behind a pillar nearby us. Then, the thing causing footsteps came in and stood looking at Sans.

"Frisk." I whispered to myself.

Sans saw him and smiled, like nothing was wrong.

"hey kid, i was wondering when you were coming back. missed ya."

"ShUt It, SaNs." He said in a distorted voice. "LeT's JuSt SkIp ThE sPeEcH."

Sans chuckled. "fine. easier for me."

They started to fight. Sans threw some bones at Frisk, but he dodged them with great skill. He then made his move to slash Sans, but Sans just stepped out of the way.

I stood in terror as I watched them fight, Frisk getting hit multiple times, but he never quit.

The fight went on until I saw Sans start to . . . go to sleep?! What was he doing?!

It was Frisk's move. He sliced the air, but Sans moved, but I could tell Frisk wasn't finished with his turn.

"did you really think i would-"

Frisk began to swig and I did something probably super dumb.

I ran and blocked the slice that would've killed Sans.