A/N: This fic is based on the baby blasters AU created by spacegate over on tumblr. Enjoy!

Sans laid as still on the table as he could. He could still feel the echoes of touch on his bones, violating and insidious. The scientist had become distracted with something on his computer, but it was never a sure thing that it would keep his attention for long. Sans often wondered what the computers did and how they worked. He knew they stored some kind of information, but beyond that... Well. It wasn't like the scientist talked to him much, only to give directions or orders.

Clicking echoed through the empty room, signaling that the scientist had finished with whatever it was on the computer. Hopefully, they were done for the day. It was often hard to tell – Sans didn't have the best sense of time, and the lights only went off when the scientist left. There was really no way for Sans to know when the experiments were over other than the scientist outright telling him, and he rarely did.

The scientist walked over to the table and made a quick gesture. Sans got up quickly. He retrieved his gown from a hook on the wall and pulled it on, tying the back with shaking hands under the scientist's gaze. When he was dressed, the scientist opened the door and flipped off the lights. Sans followed him out of the room and down the dim hallway.

The door they stopped at wasn't much different than any of the others in the hall except for the large window set into the wall next to the door. The scientist unlocked the door and opened it just enough for Sans to get in, before closing the door firmly behind him. A loud yip sounded from across the room, and a white blur hurled at him. Sans smiled tiredly at the small bone creature who jumped around at his feet.

"hey, pap." He spoke in a low voice, hoping to calm his too-excitable brother. It had been a long day, and it was hard to muster the energy to keep up with Papyrus' excitement. Luckily, the toddler didn't seem to mind. He ran in circles around Sans' feet, nipping at his ankles occasionally. Sometimes Sans wondered where his brother got so much energy.

After a moment, Papyrus froze, eyes fixed on the observation window. Sans moved instinctively to stand between Papyrus and the window, to shield his baby brother from whatever the danger was.

He turned slowly to look out the window, hoping that the scientist hadn't come back. Instead, there was someone there that he'd never seen before.

It was a monster, small and yellow and covered in scales. They were too small to be an adult, but Sans didn't know of any children down here. He watched them carefully, not as wary as if they had been an adult, but still unsure as to why they were there. The other monster was biting their lip, then their eyes widened. Sans felt tiny arms wrap around one of his legs, and he looked down to see Papyrus, shifted back to two legs, clinging tightly to him.

He looked back up to see that the monster had put their hand up to the glass. They were saying something, but the room was sound proofed, and Sans just shook his head. He was still wary, but Papyrus had poked his head out from behind Sans' leg, curious as always.

The yellow monster blinked a few times. Sweat beaded on their head, and they glanced around before making eye contact with Sans. He stared at them, barely daring to move, for several long moments before they looked away.

After a moment, they jumped as though surprised, then pulled something out of a pocket. It was... a phone? The scientist had used one before, but this one looked different from the one he used.

The monster seemed to be talking to someone. They looked nervous, more sweat beading up on their face, and Sans wondered what was happening. Who were they talking to? What were they saying? They had turned away from the window at some point, but when they finally put the phone back in their pocket, they turned back to the window. It seemed to startle them that Sans was still watching them, but they recovered after a moment and waved their hand tentatively.

Sans wasn't sure what that meant, and he tilted his head to the side, trying to figure it out. The other monster seemed to deflate a little. They smiled shakily before backing away from the window and hurrying away.

For a moment, Sans stood there, unsure of what had just happened. He hadn't even known that monsters could be yellow, or scaly. The only one he'd ever seen before was the scientist, and he was smooth and white and hard, like the walls in the lab. He knew there were other monsters, of course, he knew a lot of things, even more than the scientist seemed to think he did, but it had never crossed his mind that monsters could look so different from each other.

Did that mean that he and Papyrus might be...? No. They weren't monsters. That was what the scientist had said, right? They weren't monsters, they were creations. His best creations. Besides. Monsters didn't have bar codes like him and Papyrus did. Only things had bar codes.

Sans looked down at his brother, who was looking right back up at him. Papyrus smiled and began babbling about something, as though nothing had happened, as though he hadn't been scared, and Sans was so happy that his brother was so resilient.

A wave of exhaustion hit Sans. He swayed and, unsteady on two feet, he let himself shift until he was standing on his four paws. All of the blankets were piled up in the corner, and Sans made his way over to them. He crawled onto them and dug around a bit to make the perfect nest. Papyrus rushed over and snuggled up next to Sans, and Sans curled up around his brother. He let his exhaustion pull him down into sleep.

A/N: So, to avoid any confusion, here's a few details that might differ from the AU's 'canon'.

Sans is 5, and Papyrus is 3. Alphys is 7.

Gaster is not a skeleton in this fic. I have always had the head canon that skeletons aren't "natural" monsters, and so it makes more sense to me that only created monsters would be skeletons. Thus, Gaster is just some generic humanoid monster.

Let me know what you think!