[Undertale] Sans X Reader - Repeat, Eternally

Chapter 26 ~ Underfell, of Holy Crap You're Gonna Die

"______!" Toriel turned to you. "Take Asriel and Frisk and go!" Fire surrounded Toriel, and she moved towards the Underfell Toriel. "I will not allow you to hurt my children!"

"...____..." Gaster turned to you. "If what I think is happening is happening, then I am needed elsewhere and you need to run. Everyone is going to be extremely attracted to the Originals... but Frisk would be the biggest magnet of us all. You must not stop. If you do, something will catch up to you, and there's a good chance it wouldn't be us."

"But... I don't know where to go..." You say, hesitantly.

"Find Sans and Papyrus. They'll protect you."

"But we're right here." The breath came from your left shoulder.

"And protect isn't the word we'd use." The other breath was on your right. You were frozen in fear, but somehow managed to turn around. Frisk was in your arms. "Brother, this one is different."

"We're aboveground, idiot. Of course it's different."

"But humans and monsters, from what we've seen so far, do not come into contact often. Why is this one holding the goat's hand?" 

Asriel's grip on your hand tightened. "They're my sister!" He yelled. "They were there before the timelines started happening!" 

Both Underfell Papyrus' and Underfell Sans' eyesockets went black.

"Well, isn't that interesting?" 

"Doesn't that mean she's worth something?"

"Wouldn't Gaster want her for his experiments?"

"That old fool would reward us well, brother."

Underfell Sans grinned.

"It's settled. You're coming with me, dear." His bony grip went straight through the fabric and drew blood, which made Papyrus laugh. 

"No.."

"Excuse me?" Sans looked terrifying and angry. 

"I SAID NO, YOU F**KING PIECE OF F**KING SH*T! YOU COULDN'T EVEN VISIT ME IN THE HOSPITAL AS THE ORIGINAL YOU! WHY THE F*CK WOULD I WASTE MY F*CKING TIME GOING WITH F*CKING YOU?!" The swears that came from your mouth shocked and stunned you. They shocked and stunned everyone. Underfell Sans' grip slackened, and you slapped him, and were on your merry way.

It wasn't merry at all, actually, as you held Frisk like a princess and let Asgore piggyback you.

A Gaster-Blaster sound came from your right, and an entire section of house in front of you was blasted to pieces. You looked back.

Underfell Sans and Underfell Papyrus were riding the Gaster-Blasters.

"You're gonna regret what you just did, Kiddo!" More psychotic laughter came from him, and you stopped to appreciate that Sans was actually slightly hot like this. Wait, what were you thinking?! He was trying to kill you!

"Are we bringing her in for Gaster, brother, or are we killing her?" Underfell Papyrus asked. He had an evil grin on his face.

"Well, first, we're gonna make her suffer. Gaster never said that he needed his experiments in one piece... all she needs to be is alive." 

Damn it. Damn it. Damn it. Damn it. Where was the original Sans when you needed him?! You began to pick up the pace, but it began to rain, which was immensely unsatisfying for your footwork. You would hide in a house!

You opened a door to a house on the corner, but what you found slightly shocked you.

"Grillby?" 

".....Yes?" Over 20 of them turned their head in your direction. Extremely creepy. They were in complete synchronization. 

"I've gotta keep running, damnit!" You urge yourself forwards, slamming the door shut. Unfortunately, behind door #1....

"Hey, baby. Think it's that easy to get away?" Underfell Sans was leaning against the wall of the house. "Hey, I might actually keep you. You're really fun..." A dark look crossed his face, and you broke into a run. "C'mon, whaddya say? I'll keep you fed and everything!"

As tempting as an offer of food was for a life of slavery under Underfell Sans, you couldn't accept. 

You ducked into the next house over. You apologized to the homeowner, and noted two things. To the left was obviously a garage, and to the right, a dining room. Dark wood covered the floor, and there was a beige wallpaper. It looked cool.

You quickly locked the door, and shushed Asriel and Frisk, mentally apologizing to Gaster for what you were about to do. You opened the garage door, shoving them in. "Be quiet. Be extremely quiet, and if they try to get into the garage, hide. They saw me go in here, so they shouldn't be any trouble."

"Sister, what are you gonna do?!" Asriel was almost in tears.

"If you hear me scream, or if you hear a lot of noises, I want you to run as far away from here as you can. It will be up to you to keep Frisk safe, okay? We'll meet back at Mount Ebbot. This is really important, okay?"

"Do...do you promise you'll come back?" He asked.

"I..."

I don't keep promises anymore.

"I... promise."

But, for you, I'll lie.

There was a good chance you weren't coming back.