Hello there! If you a returning viewer, I brushed up on the Prologue and added a bunch to it. It didn't feel just right yet, too short. If you're new, then welcome! I hope you enjoy my fanfiction. :)

This story will cover the events of the neutral, pacifist, and genocide routes.

Also, SPOILER WARNING.

-TCF

Prologue

Sans was bored. It was a regular day, with him at his sentry station waiting for humans and like normal, nobody would come. This was fortunate for him, considering he had a grim responsibility to upkeep as should said humans appear, he would have to murder them.

"It's not murder," Asgore had said, "Just think of it like… removing a cavity."

A cavity. It sickened Sans that Asgore would make himself think that. Under usual circumstances, the king would never resort to violence. Disgusting.

They treated it as if they were doing the underground a favor by ending a life. Yet now, Sans had a new promise he was much more willing to upkeep. He had a choice.

The next human that came through, he would either kill them and do his job, or he would uphold his promise and protect them. Simply just to please a lady he had never met face to face.

He wouldn't have agreed to this, had it not been her tone of voice. She sounded so sad, no longer laughing much at his jokes. It broke his heart.

"If a human ever comes through this door… Watch over them, and protect them, will you not?"

He made a promise to some lady, and he didn't even know her name. Sans hated promises, but he still did it for some stupid reason. He had regretted it immediately.

Papyrus was off recalibrating his puzzles, so Sans took the opportunity he had to visit the door to the RUINS and tell that lady on the other side about his obligations.

The snow crunched satisfyingly under his slippers. He carefully stepped over a twig, not wanting to break it but at the same time too lazy to move it himself. As the huge door came into view, he felt a disturbance. Yet something seemed off, like there was a presence missing. Just as he was approaching the door to knock, it began to rumble slowly, prying open. The skeleton quickly hid behind a bush, just in time to see what looked like a human emerge from the darkness. Somehow, he could tell it was only an act. It was pretending to be what it wasn't.

Sans held his breath, while staring at the figure. It was wearing a blue and purple striped shirt, with short, brown hair. The thing that seemed off, though, was its hands. They were covered with dust. And it was smiling. The human continued to walk, showing little emotion but an empty smile and Sans pursued, careful to stay hidden. The human stepped on the twig, cracking loudly, but seemed as if it didn't even notice. It continued onwards to the bridge and stopped, as if expecting something. He crept up slowly behind the human, but he knew the human was aware of his presence. He spoke.

"Human. Don't you know how to greet a new pal?"

The human didn't move. It seemed to freeze in place upon hearing his voice, as if in shock.

"Turn around and shake my hand."

Slowly, but surely the human turned, revealing their face and grabbing Sans' hand. He could feel the dust rubbing off on his bones, making him sick. Something seemed so familiar. He stared deeply into the blank eyes in front of him when he finally recognized that expression. That smile, those familiar red eyes. They were dancing in confusion, Sans assumed they had expected a different face from his voice. A crude sound could be heard whirring from his hand. He would have to keep up his act. Just continue to be fake.

He painted on a goofy expression and spoke.

"Hehe, the old whoopee cushion in the hand trick." He chuckled softly, fake.

"I'm Sans. Sans the skeleton."

He smiled warmly at the empty face. Still fake. His life was a lie. He knew that cold, empty face anywhere; it seemed impossible, how many years had it been? At least two hundred since he'd seen those eyes.

Chara. It's been a while.