Chapter Text
He inhaled deeply walking through the echo flowers; taking in the smell of moist grass and dirt. Skeletons didn’t need to breathe of course, but that doesn’t mean they don’t enjoy it.
Sans had been walking through Waterfall for a while now, on his way home after visiting Alphys on some unofficial business; taking his shortcuts would have been much faster than walking all the way back to Snowdin, but there was no rush so Sans had decided to take his time and see the sights.
He walked past his outpost, briefly stopping to make sure everything was still in place for the next time he had sentry duty there. Papyrus wouldn't be happy if he came past here, possibly to visit Undyne, and found it in shambles. Satisfied, he continued on to where his telescope stood.
“Hehe...” he chuckled to himself, remembering all the times he’d tricked monsters by putting red paint on the eye piece. No one fell for that anymore these days, but those had been some good times.
Walking further a nagging feeling slowly began to emerge at the back of his mind. Something wasn’t right here, but what? At that moment he realised that he was walking through a corridor that shouldn’t be there.
The area his telescope was in should lead straight to the room with the echo flower and the cheese crystal, so why was this suddenly here? Looking back he couldn’t even see the previous room anymore.
He kept walking, expecting the corridor to end at any moment. When it didn’t he started running, but there was still no room in sight.
Coming to a halt Sans looked around. “What...?” In both directions it seemed to be a never ending corridor.
“Alright then”.
Summoning up his magic Sans tried teleporting to Snowdin, but as soon as he called upon his magic he knew something was wrong; the feeling he usually had while using his powers replaced by something odd and foreign.
“Omph” he exclaimed as he hit the ground face first. “What now...?”
Sitting up he could see he was still in the seemingly never ending corridor but one thing was blatantly different: a grey door stood before him.
Sans got to his feet, examining the door in confusion. He’d never seen a door like this in Waterfall before, but then again he didn’t know if he was even still there.
He felt really uncomfortable about the whole situation, but with no end to the corridor in sight he didn’t really think he had another choice.
Taking hold of the handle Sans carefully opened the door, a mist pouring out of it as soon as it was ajar.
Inside everything was pitch black and Sans couldn’t tell where the floor, ceiling or walls were, if they were even there at all.
Carefully stepping forward he could feel his feet touching solid ground. “Ok, check on the floor” he mumbled, taking another look around.
On closer inspection Sans realized that there was something in the room that wasn’t all black; the shape of a man was sitting further out into the room, unmoving, seemingly unaware of him being there.
“Hey buddy, you know how to get out of this place?” Sans called out while walking closer. There was no response from the figure.
“Welp, not the talkative type eh? Well I-“ he suddenly stopped as he got a better look of the person in front of him.
A skeleton dressed all in black, cracks in his head and holes in his hands; someone Sans instantly recognized.
“Gaster?!” he exclaimed, running closer. Was Gaster ignoring him? No, surely he wouldn’t.
“Gaster? Can you hear me?” Gaster didn’t seem to hear him, or if he did he showed no indication of it.
“Hey, why aren’t you answering?” Sans asked reaching out a hand.
As soon as he touched the former scientist he knew that he’d made a mistake; magic rushed into his hand and arm, spreading rapidly throughout his body and enveloping his soul in a burning sensation. The worst part was that no matter how hard he tried to struggle he could not seem to remove his hand from the other’s shoulder.
“G-Gaster?!” he stammered through the pain, collapsing to his knees and looking up at the scientist.
Gaster’s head lifted for a moment to look right into his eyes. Sans could clearly see the sadness in them, a black liquid dripping from one eye socket.
‘I’m sorry’ suddenly echoed in his head as Gaster scattered into dust.
Sans was now free but the pain continued, seeming to gather at his soul; a sensation he couldn’t describe in any other way than being burned from the inside out.
It was agony yet somehow it started to become even worse. He screamed, desperate for the pain to stop, only for it to keep increasing.
Eventually it became too extreme and Sans blacked out, a blissful darkness overcoming him.