[Undertale] Sans X Reader - Repeat, Eternally

Chapter 66 ~ Alphys Does The Right Thing

"...I c-can't, Gaster. Not this. This is pure t-torture." 

"It's going to save them, Alphys. You've always been an apt pupil, so why stop now? You said yourself you were dying to do an experiment with me."

"N-Nightmare s-serum is not an experiment to b-be played with, Gaster. Nightmare serum can destroy souls." 

"That's what I'm hoping for." 

Alphys' eyes widened. She never signed up for this. Gaster had told her it was a tranquilizer dart of pure magic; she was told to shoot both you and Sans. That you were both freaking out. 

~Rewind to mosquito bite.~ 

She gripped the awakening serum. Gaster turned around, watching your nightmare with extreme interest. He seemed sad; almost sullen.

"I'm sorry." He whispered. "This saves us all. You just need to stop holding on to your soul, _________." His skeletal fingers brushed across the screen. "Just give up your DETERMINATION, and Sans goes free. You go free." 

He turned to Sans, who was being assaulted by dreams of Papyrus' death over and over again. 

It was necessary, Gaster told himself.

This was different. This was the very first time in eternity Gaster had tried something like this. He begged for it to work. He really did.

This wasn't the first time you had destroyed the entire universe and any adjoining to it. 

He had to stop it. He had to stop eternity from happening. Destiny, fate, whatever you'd like to call it.

Unfortunately, eternity had other plans. 

Alphys jabbed the needle into your neck, and you shot up from the table, gasping for air. 

Gaster turned, shock freely exposing itself.

He grabbed the Nightmare Serum dartgun, and pointed it at you... but Mettaton burst through the roof and landed on him, knocking him out. You look between Alphys and Metatton.

"Metatton has a homing signal." Alphys shrugs.