Sans sighed as he waded through the pile of notes and gizmos.

"you know pops, it's been five years and you still haven't made a break through. Maybe it's time to... i don't know... give it a break."

The older skeleton stood with his back to Sans, enraptured in the diagram that was before him. Sans's words had fallen upon deaf ears apparently.

"or not," Sans said as he stared at the scribbled equations that littered the majority of the pages that littered the lab.

Gaster's laboratory had changed over the five years, to the point where it had even been relocated to Hotlands as to be closer to the Core.

After your death Gaster had thrown himself into his work, investing his time to finishing the Core. It had been a way for him to deal with your death, a way for him to handle the grief and guilt he still felt. The Core had been created 2 years later, however Gaster spent the next three obsessed over the idea that he could somehow bring you back from death with your soul.

Sans closed his eyes, cursing himself for what he was about to say, "dad... she's been gone for five years... i think you should stop with this plan of yours. before you hurt yourself or someone else."

Even Sans had to admit your death had been a blow. Not only to Gaster but also to himself and Papyrus. However, his father had gone too far in his grief, believing he could bring things back that were long gone. Cheating death. It just wasn't right.

Gaster finally turned to face his son.

"I can't, not yet. I know I am close to figuring it out. I can bring her back," Gaster stated. He strode past his son and came to a stop in front of the specially designed jar that protected the suspended green and purple heart. The faint light illuminating Gaster's features as he stared at it.

Sans rubbed the back of his neck nervously, "dad, papyrus is getting worried. You don't come home as often and the king is starting to wonder what you're doing locked up in here all the time."

Gaster's face softened, "I... apologise for making you and Papyrus worry. Asgore is a good friend... however he mustn't know what I do here Sans. If he discovers I have her soul he will demand I hand it over to him.... I can't let him take the only thing I have left of her." Gaster muttered as he pulled away from the soul.

He pinched the bone between his eye sockets and closed his eyes in weariness.

"will you at least try and get some sleep?" Sans asked.

Gaster sighed, "I assume that rest would not hurt."

As quickly as the relief to his father's acceptance of rest had filled Sans it disappeared with the flashing of red and the blaring sound of sirens that filled the lab.

"what's going on?"

Gaster's eyes had widened in shock and he was now rushing to the main control pad of the laboratory as large warning signals began to fill the screens.

"I don't know... the Core has become unstable. As if something or someone with a force of energy even greater than the power generated by the Core has entered the underground," Gaster stated, his hands moving swiftly over the keys.

"That should be impossible though... the only thing that could possibly rival the Core in power is a disruption in the timeline or someone who has the power to determine the fate of a timeline entering this dimension."

The lights continued to flash as sirens blared. The room shook as Gaster and Sans lost their balance. Parts of the wall began to shake and cracks formed in the floor.

Regaining their footing Sans spoke up, "so you're saying that someone with an extreme amount of DT has entered the underground? How is that possible?"

"I am unsure, however that is the only explanation I can think of. I am going to attempt to stabilize the Core, at least until we can find the irregularity."

Returning to the computer Gaster moved frantically as he input codes and attempted to enter the systems energy code.

Sans however was more concerned about the cracks spreading into the ground as sections of floor gave away, falling into the dark abyss below.

'dad, we need to get out of here now!"

"No, I can't leave. If I don't stabilize the Core the entire Underground could be ripped apart," Gaster yelled.

Sans looked frantically at the laboratory door then back to his father, "how can i help?"

"I need you to hack into the failsafe cooling system and set it off manually. If we can cool the Core to a certain point I can contain the rogue power and bring it back under operation."

Sans nodded and began to work, it was pretty simple however the cracks in the ground were starting to crawl closer and closer to the two of them as parts of the roof and walls crumbled away. The whole room could give way without a moment's notice.

Finally, Sans initiated the failsafe.

Gaster moved with such speed and confidence as he inputted the last of the information needed to stabilize the core.

With a final shudder, the Core became still. The flashing lights ceased and the room became eerily quiet.

Sans slowly backed away from the control panel, his eyes glancing around at the damaged room, "we need to get out of here. the entire room is too unstable for it to be safe," Sans told his father.

Gaster followed his son as they made their way towards the exit. Moving tentatively as not to disrupt the balance of the room.

However, as the Core shuddered again unexpectedly, Sans felt himself lurch forward.

Eyes flicking towards his father he realized Gaster had pushed him out of the path of falling rubble.

The floor between him and Gaster had fallen away into oblivion.

"dad!"

Gaster's shocked gaze moved from the floor to his son's stricken expression, "Sans's get out of here."

"i-I can't. not without you!"

Gaster grinded his teeth, he knew there was no way he would be able to make it to Sans.

"Sans... please. I need you to look after Papyrus... to tell him that I love him... that I love you. So please, leave."

Grief was etched into Sans's face as he backed away slowly, tears threatening to spill.

"i.... i love you too, dad."

With that Sans turned and fled.

Gaster watched as his son disappeared, relief flooding him.

His attention was turned to the glass jar in the middle of the room however as the glow of purple and green intensified.

Walking towards it, as though he was in a dream, Gaster closed the distance between himself and your soul. Around him the carnage as the room fell apart seemed to fade out of existence as the soul pulsed strongly. Removing the jar Gaster held the soul close to him as the room shuddered one final time before the ground fell beneath him. Gaster was falling however his decent meant nothing to him as he held your soul close to his chest.

It was so warm, and alive. Just like you had been when you had been alive.

There was an emotion in your soul. An emotion he had not felt so strongly since your death.

Love

Not LOVE but love

Your soul was filling him with warmth and love as the light engulfed him. He could feel you, it was like you were embracing him once again. Gaster closed his eyes as the Core's radiation teared at him. However, your soul seemed to be acting as a shield, protecting him from certain death.

He should have been dead, but he wasn't. Your soul, your warmth and your love had protected him.

Gaster faded from the physical world, your soul remaining with him as he passed through timelines, images of other versions of his own world filling his mind.

Finally, he found himself in a dark room.

He was not alone.

A familiar presence was beside him, was part of him.

________________.

And it is done~

Hope you guys liked this Fanfic (even though the end wasn't really a happy one ':) )

Thank you for staying with this Fanfic till the end and being such great readers~

Love ya all~

See ya next time :)