Waking up with a throbbing migraine, Sans was greeted by the sight of a very annoyed Gaster.

"Sleep well?"

"No, not really, ugh, what happened?"

…

Gaster backed away from Sans and walked over to the machine that would have separated Chara from Frisk.

"Tell me Sans, were you simply incapable of thinking clearly during your fight?"

"Huh?"

"Was your mind unable to think further than killing Chara as you fought her?"

"Of course I could think further than-"

He got no further as Gaster slipped through the air and slapped him aside with the back of his hand.

"THAN WHY DIDN'T YOU THINK WHEN YOU ATTACKED!?"

Kain and Grillby ran to Gaster and tried to calm him down while Sans looked at him in shock.

"Your RECKLESS actions costed us the extractor and the life of Alphys Sans…"

He remembered now, the attack, how Chara was able to use him to do more damage than she ever could.

"No…"

"Denying the truth is a fool's errand, do not waste my time if you intend to deny your own actions!"

"Alphys…"

The pair had finally been able to calm Gaster down and backed off a bit.

"…You disappoint me Sans…"

Those words, stabbed deeply into the comedian, he could feel his arcane heart drop to the floor.

But in the end, Sans got to his feet.

"I'm sorry… I'll take care of this, myself."

He walked to the elevator, only to be stopped when they called to him.

"Sans what are you going to do huh? She is faster than you, stronger than me…"

He looked over his shoulder to Kain.

"I don't know, but, I'll figure something out, I owe Frisk that, I owe, Alphys that much…"

"You won't be able to touch her, she will sense your anger coming from miles away…"

…

"I Know Gaster, it's what I'm counting on…"

With that, he summoned up a Gaster Blaster and used it as a platform for him to rise up through the shaft.

Kain and Grillby used the moment to sit down and catch their breath, they had been spending all the time to transport the fallen monster dust from all the refugees to the surface of the underground where it could be properly buried.

All the while Gaster tried to restore the destroyed machine, but it was irreparable, Sans's attack was simply, too catastrophic for the machine's fragile parts to withstand.

Yet, as Grillby and Kain took a moment to relax, they saw something.

Gaster was, smiling and thinking.

"What, are you planning Sans…"

It took quite some time for the genius monster, to realize the intentions of his grandson.

"Oh my, Kain, Grillby, gather what you need, we MUST go after him, right now."

There was a certain desperation in Gaster's voice that, unsettled the pair.

They both only grabbed their swords and followed their friend as he headed up the elevator shaft.

Yet when they reached the top, Sans was nowhere in sight, there were no tracks for them to follow, it was like he, vanished.

"Using his construct to fly off in safety… very smart indeed."

"Damn, if he is using his Blaster to get around, we can't track him, we can't get to him."

While Kain and Gaster discussed matters, Grillby looked around.

They noticed his, unique actions when he raised his hand up and snapped his fingers.

They both watched him, curious as to what Grillby was doing, but the flame, sprinted off in a direction.

"GRILLBY!"

Both Kain and Gaster chased after him, the former was concerned for his friend while the latter, knew that he found a way to track Sans even if he was in the air.

They were going to find him and stop him before he made the biggest mistake that he ever could make.

Sans knew that he was being followed, he felt it, and although he surprised and happy, he was, annoyed.

They were going to get in his way.

"I'm sorry guys…"

He summoned up several other Blasters and had them go in other directions.

"You know this is mistake… right?"

"Ha, even my own mind is against me huh?"

"I'm not against it Sans, but we both know that if, and I stress the if, we can find Chara, than she will kill you…"

"She had plenty opportunity to kill be before, no, she is, playing with me."

Sans felt disgusted when he thought back to that kiss.

"You can't change the past…"

"I know that."

"Then why are you trying so hard?"

"Cause Frisk can…"

"There is no way that she will be able to turn the clock again and you know it."

It was annoying but, that was true.

"…You aren't going to do what I think you are, are you?"

"What other choice do I have…"

"There is no guarantee that it will work!"

"I have no other choice, without that extractor we can't get Chara out."

"You'd really do it, even though you know what she did for you?"

"I NEED to do it BECAUSE I know what she did"

…

He didn't like this, he never could, not after knowing what Frisk did for him.

"Look, I hate this too, but, I'd rather have it done like this, than ever leave her trapped in there with Chara…"

The skeleton felt a ghost sensation of the knives in his hands.

"You know that she will not be easy, right?"

"I kind of figured that when she handed my rear bones to me…"

"Ha-ha, Sans, just, be careful alright."

"I'll try, but, do you think that you could, do that again?"

She knew what he was referring too and after a large pause of silence from her, filled by the howling winds, she replied.

"It took a lot of effort to do it the first time, but, I'm sure I can squeeze out another minute or so of filtering…"

"Thanks, I'll need it"

He knew that, this was probably going to be his end, and, he was alright with that, even if he wasn't going to survive, he would take her down with him, one way, or another.

His attention was split for a moment when he saw through the eyes of his blasters, sight that allowed him to gaze across the entire underground and see the tiniest markings with precision. Kain was following one of them Grillby was following another, he couldn't however see Gaster, he was missing…

"So he gave up the search huh?"

He knew better, his grandfather, was up to something…

But it was too late, he wouldn't get in Sans's way, not anymore.