*Kiara*

I woke up in an endless black room. I stood up and looked around, figuring how to get out.

"Kiara." Gaster's voice made me stop.

"Gaster?" I asked and I saw him a few meters from me. I looked around once more and asked him.

"Am I back in the void?"

"Physically, no. Mentally, yes." His answer came out.

"So... What am I doing here?" I asked as I walked up to him and hugged him.

"Well, I just miss you and I can't seem to contact you in your thoughts. So I might be appearing on your dreams." He explained. I nodded.

"Were you watching the whole time?" I asked him.

"No. I can't see anything or hear anything in your trip. It seems that the connection is weak."

"That's a bad thing."

"It is."

"Well as you know, we came from Underfell. We finished the machine and it dumped us in Underswap."

"I think you should give me updates each time you sleep. I will be appearing in your dreams."

"K, dad. See you next time."

"Goodbye."

~*****~

I woke up cuddled to Sans. I sat up and looked around. US Paps and US Sans were still sleeping. My Sans is sleeping too. US Kiara was sitting in the corner smiling at her sleeping brothers. I walked up to her and sat down beside her.

"Hey, how are you feeling?" I asked her.

"It feels great. Like I shouldn't have kept it all to myself." She replied a smile curving on her lips.

"I'm glad to hear that." I said and looked up to the stars.

"Should we wake them already?"

"Yeah."

*****

We continued walking and we saw US Alphys. Wow, she looks very tough.

"Alphys. You don't have to fight them. They're with me." US Kiara told her. Alphys looked at us suspiciously before lowering her weapon.

"Fine. You may pass." She said and we walked through quickly. Gosh, Underswap Alphys looks so cool.

We made our way to US Undyne's Lab. When we entered, we saw the fish lady looking at the big monitor.

"Hey Undyne." US Paps greeted. Undyne looked startled.

"O-Oh! H-Hi there!" She looked at us and there was an awkward silence.

"Uh..." I said uncertain while looking at my brother. Well, this is awkward...

"Undyne, we came here to go look at my lab." US Kiara said. Undyne nodded and hurriedly guided us to the same room we went to in Underfell. It's still the same so no biggie.

"So... Where's the machine?" I asked. The other me pointed towards a curtained portion and plopped on the couch. I mumbled a thanks and hurried towards it.

"God..."

The machine wasn't even half finish. I turned my head back at US Kiara.

"You haven't done much work on this?" I asked sternly.

"Too lazy and less time." She respond. I groaned. Sometimes I wonder if US me and UF me were switched.

"welp, let's just start building it up." My Sans said.

"I'll help." US Paps offered.

"me too!" US Sans said, his eyes turning to stars.

"Bro, just have your cooking lessons with Alphys." US Paps told his brother.

"Okay!" US Sans yelled and rushed off.

"So, how does this work?"

~*****~

"I think this goes there." I pointed out.

"no, it goes to the other side." Sans said and stick the piece of metal to where he said it should be.

"I think that's right." I adjusted my glasses. I'm wearing a lab coat and glasses. Sans has the same attire as me. Heh, Sans look like the Sans in that timeline I saw. (A/N: Sciencetale!)

US Sans opened the door with a tray of lemonade and tacos.

"i, the magnificent sans, have brought you some snacks!" US Sans said with an excited voice. Behind him followed US Kiara and US Paps. I giggled at his childish attitude.

"Thanks, Sans." I said with a smile.

"you're welcome, human!" His eyes were practically stars.

"So, close to finishing it?" US me asked.

"Well, it looks a little bummed. What happened anyway?" I asked, nudging my glasses up.

"Well, it sorta, didn't work properly at the first try?"

"That explains a lot." I replied.

"how many times did you attempt to make this machine work back at our universe?" My Sans asked me while he was looking at the blueprints.

"A couple of million times. Including the resets." I answered with a matter-of-factly tone.

"what? and you didn't tell anyone about it?" He asked in shock. I chuckled.

"I keep far more secrets that you don't know, Sans."

"Hey, can someone hand me a wrench?" I heard US Paps said. US Sans quickly scurried off grabbing a wrench and giving it to his brother.

"Thanks bro." He proceeded on whatever he's doing on the machine.

"you know, we've been here for a couple of days and I already feel like it's home." Sans said with a sad smile. I remembered something.

"Hey, don't ever forget about your real home. once you feel like that, you might forget that you don't belong here." I warned him, just like how Gaster warned me.

Sans blinked then smiled. "of course i won't forget."

We continued working on the machine while cracking jokes and drinking lemonade.

~*****~

At last, the machine is done. I really hope it will bring us home this time.

"Bye me." I told my counterpart. She chuckled.

"Bye me. Thanks by the way."

"For what?" I asked.

"For this." She gestured to her brothers. I smiled.

"Nah, no need to thank me. Anything for a friend."

"A friend? You're a first." We both laugh. "See you someday."

Sans was already in the machine. I stepped in. We were still wearing our lab coats. We waved at them as Sans pulled the lever and we both got lost in the darkness.