The first time Sans' brother opened his eyes was late one night.

It was several months after Sans was given his brother, and the Soul fragment was almost three fourths the size of a normal Soul.

Sans should have been asleep. He knew he should have been. Tomorrow Gaster was giving him another of the physicality serum injections, and, once again, he had increased the dosage.

This always happened when Gaster told Sans he was increasing the dosage. Sans got nervous about it, got scared he wouldn't be able to handle it. This time especially, because he had promised his brother he would never let him be a part of the DTW experiment.

So now, what would happen if it was too much, and Sans died? Then his brother would be forced into his place.

So he was awake.

Sensing Sans' nervousness, the small skeleton was also awake and nervous.

Sans was trying to calm him down, get him to sleep at least. So Sans was playing with him.

He would tickle his brother's ribs, laughing as the little figure grinned and tried to squirm away from Sans' hand. He always ended up rolling into Sans' side, where Sans would hug him close. After a second, Sans would loosen his grip, letting him wiggle away, before beginning the game anew.

In reality, this probably calmed Sans down more than it did his brother. But, for the most part, they both enjoyed the game.

And then, the small skeleton caught Sans' hand.

Sans watched, a little surprised and confused, as his brother turned his hand over, small fingers trailing over Sans' broader ones, before he set his palm against Sans', splaying his fingers out to match.

Sans looked at his brother.

He was looking at their hands, eye sockets wide and curious.

For a moment, Sans just watched his brother, still fascinated by their hands. Then Sans leaned over a little, into his brother's range of vision.

"...hey, there."

For a moment, the small skeleton just stared, and Sans stared back.

Then his brother's face split in a wide smile, and he reached forward for Sans. Sans pulled his brother close, settling his forehead against his brother's, both of them just looking at each other, grinning like idiots.

Sans didn't need to be told that his brother recognized him, that his brother knew him and loved him.

Words, in that moment, were unnecessary. There was simply a connection between the two, finally, really able to see each other, something strong and deep, a bond between their Souls.

There was something in the knowledge that his brother was aware, and could finally see, that made things all the more real for Sans. Before, Sans had promised to protect his brother, but now, with his brother looking in his eyes, Sans knew that he accepted that promise, he would hold on to it, that he would cling to Sans as a lifeline.

And then, the small skeleton closed his eyes, tucked his head down against Sans' chest, and slept.

Sans held his brother to his chest, still reveling in in the closeness.

After a little while, he too fell asleep.

~o0o~

The next morning, Sans jolted awake when Gaster came into the room.

As he sat up, his brother began to wake as well, blinking as he tried to snuggle back against Sans' chest.

Gaster noticed. "S643 opened its eyes."

Sans nodded. "uh huh." He settled his brother into his lap.

"Well. Come on. I have work to do today."

Sans started to get up, then stopped.

Gaster sighed. "What now?"

Sans looked at his brother. "... he moves around a lot more now, and he can also see..."

Gaster saw where Sans was going with this. "It will be fine, Sans. Leave it here."

"what if he falls off the bed?"

"You fell off the bed several times. And then you learned not to."

"but what if he gets hurt?"

"Then it'll learn faster."

"i don't wanna just let him get hurt!"

Gaster scowled, sighing irritably. "If you're so concerned, you can leave S643 with Jeff. But hurry."

Satisfied with this solution, Sans slipped off the bed and trotted out of the room, holding his brother tightly.

Jeff was just stepping out of the elevator when Sans found him. Jeff smiled when he saw Sans coming. "Good morning, Sans."

"hi, jeff. um, can you do something for me? can you watch my brother while i'm... y'know, unconscious? he opened his eyes last night and i was just worried..."

"Of course, Sans. Here, let me see."

Carefully, Sans slipped his brother into Jeff's arms. The small skeleton tried to hold on to Sans' shirt, looking scared all the while, but Sans gently pried his hands away.

"hey," he said softly to his brother, "it's okay. you know jeff. he'll take good care of you while i'm gone. it's okay."

Jeff gave the small skeleton a snuggle, cradling him in his arms. In turn, Sans' brother looked up at him, his fear temporarily forgotten in his curiosity over looking at Jeff's face.

Jeff smiled at him. "Hey there. So you can see, now, huh? You're adorable."

Sans' brother had heard Jeff's voice, and recognized it. He smiled up at Jeff.

Sans nodded. "looks like you'll be alright. i need to get going, or gaster's gonna flip out."

"Alright. See you later, Sans."

Sans turned and started to walk away. He knew that Jeff would take good care of his brother, so there was that worry taken care of, at least. He was still nervous about surviving the increased dos-

Sans was about halfway down the hall when he heard a yelp.

He turned around to see his brother attempting to struggle out of Jeff's arms, one hand extended in Sans' direction, an expression of worried fear on his face.

As Sans looked on, his brother let out another cry, a loud, wordless plea for Sans to come back.

Sans' Soul almost broke as he turned away. He knew that he had already taken longer with this than Gaster would have wanted, and if he went to his brother now, he might not be able to leave again.

But that didn't make it any easier.

~o0o~

Jeff found that taking care of Sans' brother was easy, once he calmed down, but not at all enjoyable. It was downright depressing.

The small skeleton missed his brother, that was obvious. He just sort of curled up in Jeff's lap, staring blankly ahead, sometimes letting out small sighs or sad whimpers.

He was never like this when he was with Sans.

Jeff did the best he could, keeping Sans' brother close, hugging him and snuggling him, telling him that it was okay, that Sans would be fine, and soon they would be together again.

A few hours passed.

Jeff decided it was time to go see if Gaster and Sans were done with... whatever experiment Gaster had for today. He rose, cuddling Sans' brother to his chest, and headed for Gaster's lab.

Just as he was slipping in, Gaster was closing the door to Sans' room. So, then, they had just finished, and Sans was probably unconscious.

Gaster barely acknowledged Jeff before he was at his desk, working on something or other.

Jeff carried Sans' brother into Sans' room. The small skeleton let out a happy shout on seeing Sans.

Sans was indeed unconscious, lying sprawled on the bed. He was shirtless, Gaster having left his shirt and lab coat folded on the foot of the bed, but, Jeff noted with no small amount of relief, there were no bandages wrapped around any part of Sans.

Jeff stepped over to the bed and set Sans' brother next to Sans. He immediately cuddled up to Sans, and Sans, out as he was, shifted, rolling onto his side and curling around his brother, hugging him. The smaller skeleton let his skull rest against Sans' sternum, fingers lacing between Sans' ribs as he let out a sigh of contentment.

And then Jeff noticed something.

Sans' Soul.

It was glowing brighter than usual, the light filling his ribcage, casting light shadows through his ribs.

Jeff smiled.

They really were close.

~o0o~

Even with Gaster's agreement to not experiment on S643, he still preformed the same weekly checkups on it as he did Sans. This was necessary, to ensure that it was still growing properly, and there wasn't some... problem.

So first was Sans, lying on the table, hooked up to all the machinery, with S643 lying on his chest, napping. When Gaster was finished with him, it was S643's turn, and Sans sat on the edge of the table, holding S643's hand the entire time.

Gaster had just finished checking over S643's health. It was growing much faster than Sans had.

"Sans. I want you to start adding the growth serum to S643's meal every day."

Sans head snapped up from looking at S643. "what? no!"

"Sans."

"you said you wouldn't use him for the dtw project!"

Gaster sighed, rubbing his nasal bone. "The growth serum is not a part of the DTW project. It simply promotes a stronger, healthier body, at a faster rate."

"yeah, but he'll be stunted!"

"That hardly matters. It will be stronger."

"besides, i thought you said you didn't start giving that stuff to me until i was four months old! he's only three!"

"Yes, but it's opened its eyes a month ahead of you, and used it's voice an entire three months before you. It is growing faster."

Sans looked like he was about to protest still.

"Sans. S643 will be fed the growth serum. The only difference is whether it's you feeding it to S643, or me."

Sans sighed, looking down at S643. Gaster could remember looking once similarly to that to Sans.

"... okay..."

Perhaps that was the cause of the growth. The unconditional love, the constant care, the endless snuggling...

Gaster felt something bubbling up in his chest.

No. No, I can't. I gave that up, in turn for strength. Strength to do what needs to be done.

He looked away as Sans lifted S643 off the table.

This will work.

I will do this. With Sans, I will break the Barrier. I will kill humanity.

I

Do not need

Love.

I

Have

LOVE.

... That will be enough.

§

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