It was what someone would assume to be nighttime in the Underground. Snowdin Town lay in peace, most of its citizens already in bed and fast asleep.
The house at the end of the street, however, was still lit up. In one of the rooms upstairs, Sans was still up. Sitting on a chair next to his brothers bed, reading him the end of his good night story.
"and with that, the fluffy bunny hopped home, ready to see his friend again the next day. the end." he finished, closing the book. Papyrus was asleep already, snoring slightly with his unique laugh.
Sans put the book back in its shelf and opened the door to return to his own room.
Stepping outside, he heard sniffling in the living room. It was very soft, but it was there. He took the stairs that led down and switched on the lights. With a small gasp, he spotted Frisk sitting on the sofa, face buried in their hands and their whole body trembling.
"hey kiddo. what are you doin' down here?" he asked and placed himself next to the child. Frisk just continued to sob but leaned against the skeleton, wrapping their arms around him.
"I'm sorry... so, so sorry... please believe me." they whispered. Sans seemed confused for a moment.
"what are you sorry 'bout? what happened anyway?" he questioned, petting their head. Frisk sniffed one last time before looking up at him. "N-nothing really. I just had a bad dream. R-really nothing to worry about."
They lied and Sans knew but he decided to play along. "c'mon kid. y'know you can tell me, right? i'm not gonna hurt you." he said with a softer grin. Then silence came over the two of them before Frisk spoke up again.
"But you would if I killed everyone, right? I mean, even if it is not my fault..." Sans' grin disappeared as much as it could. is the kid talkin' 'bout what happened? "is that what you were dreamin' 'bout?" Frisk nodded.
Should they tell him? Would he be able to understand it? Frisk was not sure.
"I mean it kind of IS a bad dream, but on the other hand it's NOT but it's really complicated and... you probably would not believe me if I told you..." Frisk kept their head low. Sans hesitated for a bit and then... "try me, bucko! you can trust me, you know that."
"Huh?!" Frisk seemed confused. "tell me and i will try my best to understand, alright?"
Frisk said nothing, just thinking to themselves if it was the right thing to do. Their heart kept pounding in their chest, stronger and stronger with each passing moment. It almost hurt, but of course the pain was nothing compared to what happened in their 'dream'. And knowing that, they were filled with determination to tell Sans the truth.
"Okay, I'll try and keep it simple... I, uh, I.. have a special ability that allows me to RESET. It's like, uhm... jumping back in time? Yeah, time travel seems closest to resetting, but only to the past. I have this power because of my DETERMINATION. I can also LOAD and SAVE." They paused, letting Sans take the information in.
"so... like in a video game?" The skeleton asked. Frisk giggled. "Kind of. Sounds crazy, doesn't it?"
"nah. sounds pretty cool. well, not as cool as papyrus, but you know what i mean." Sans shrugged.
"Of course I do." Frisk said with a slight smile.
"wanna tell me more now?" Sans asked. Frisk took a deep breath and exhaled with a sigh.
"Alright, I guess I don't have a choice now that I started." They said. "I, uhm... I had this 'run' before. The 'True Pacifist Run'. I befriend everyone and get my 'Happy Ending', as Flowey calls it.
"Every monsters dream comes true and we get to the surface. We lived like this a couple of months and were just happy. I had a new home with Toriel as my mom. I got to see you, Papyrus, Undyne, Alphys and everyone else every day. No worries and I even got Flowey to be my 'friend' in a way. And mom allowed him to stay with us. Then one day, Flowey and I were talking about the time in the Underground."