The next morning, Mettaton explained the situation to Undyne, after she had asked about Alphys.
"So she'll be a baby for two weeks?" Undyne asked.
"That's what the note said. She's apparently been under a lot of stress for a while," Mettaton replied, sitting with Alphys on his lap. Alphys looked about a year old at this point. She was gumming on her hand, getting drool all over herself.
"Good morning deary," Muffet said, walking into the room.
"Oh, hello darling," Mettaton said.
"Oh, I wanted to tell you that I saw Alphys in the lab last night," Muffet said. "She was writing another note. You may want to check her pockets."
"Oh, alright," Mettaton said. After a small search, he pulled a folded piece of paper out of Alphys's coat pocket. He unfolded it and read it:
"Mettaton. After further examination, I've discovered that the regression serum has a few side effects I forgot mention. One of those side effects is temporary memory loss. During the day, I will not remember anything about myself or my friends. My mind will be in the same state as a one year old child's. This effect should go away each night at midnight. If you have any confusion, please talk to me tonight."
"What does it say?" Undyne asked, trying to peak over Mettaton's shoulder to read the note.
"It says that she doesn't remember us," Mettaton said, folding the note back up and putting it in his pocket.
"W-What?!" Undyne exclaimed, panicked.
"Relax, darling. It's only temporary. She should gain her memory back when the serum wears off," Mettaton said.
"O-Oh. That's good," Undyne said, relieved. Alphys suddenly whimpered. She took her hand out of her mouth and looked at Mettaton.
"What's wrong, Alphys?" Mettaton asked, looking at her. Alphys just babbled, whimpering.
"She may be hungry," Undyne said. "I know I am."
"Oh," Mettaton said, standing up. "Although, I'm not sure what she can eat. She woke up without any teeth."
"Well, I did bring a few baby bottles," Muffet said, joining the conversation. "She could use those."
"That works," Mettaton said, trying to comfort Alphys, who was close to crying. "Please hurry, darling. I think she's getting upset," Mettaton said. Muffet nodded and headed to the kitchen. Alphys babbled, whimpering. She looked at Mettaton with tears in her eyes. "Don't worry Alphy," Mettaton said, trying to keep her from crying. A few minutes later, Muffet came back and handed a bottle to Mettaton.
"Here you are, deary," she said.
"Thank you," Mettaton said, putting the bottle in Alphys's mouth. Alphys immediately started to suck on the bottle, calming down. "There we go," Mettaton said, smiling. After breakfast, Mettaton took Alphys to her room to try to get her to take a nap.
"She's not gonna take a nap. She just woke up," Undyne said, following them.
"Well, then what should we do?" Mettaton asked.
"Well, you could play with her. She is a baby after all," Undyne said, smiling at Alphys, who was gumming on her lab coat.
"Play with her?" Mettaton asked, confused.
"Yeah, there's a lot you can do," Undyne started. "You can tickle her, play peekaboo, hide and seek. There's lots of things to entertain a baby,"
"Okay," Mettaton said, setting Alphys down on the floor in front of him. Alphys looked at him and giggled, reaching for him. Her sleeves drooping over her tiny hands. Mettaton chuckles and tickled Alphys. Alphys rolled onto her back and squealed with laughter, kicking her legs. Mettaton smiled. Alphys sat up and looked at him, giggling. He reached up and placed a hand on the robot's nose. Mettaton chuckled and booped the tiny lizard's nose, earning a giggle from her. "I guess she is kinda cute," Mettaton said, picking the lizard up.
"Yeah, she is," Undyne said, smiling at Alphys.
Asriel sat in the attic, drawing with Toriel. "Do we have to use crayons, Mom?" Asriel asked, looking up from his drawing. "They're kinda hard to draw detail with."
"Sorry, honey," Toriel said. "I couldn't find the markers." Just then, Frisk crawled up the steps to the attic. She took one look at Asriel and squealed in delight. Knowing exactly who he was.
"A-Azzy!" She squealed, crawling quickly to him.
"Frisk!" Asriel smiled, hugging the toddler. Even though he had been a flower, he had experienced and remembered everything that had happened since then.
"Aww," Toriel said, smiling. "I was wondering if you two would ever meet again. After the barrier broke, she told us everything that had happened."
"Yeah, but I remember everything. Even though I was Flowey, I still know all that has happened before now," Asriel said, smiling.
"Well, I think you two will get along just fine," Toriel said.
"Yeah," Asriel said, smiling at Frisk. Frisk smiled and hugged Asriel like a teddy bear, snuggling into his soft fur. Asriel giggled. "Hey Mom," Asriel asked. "When's Dad gonna be home?"
"Oh. Your father is on a trip regarding the remains of the Underground," Toriel said.
"Oh," Asriel said, looking down.
"Don't worry, honey. Your father will be home soon," Toriel said, smiling. "He'll be so shocked to see you again, too."
"Yeah, I can't wait," Asriel said, smiling.
"Okay, I think it's nap time now," Mettaton said, picking up Alphys, who was still wide awake.
"You're not gonna get her to take a nap, trust me," Undyne said, with a chuckle. Mettaton sighed and set Alphys back down. Alphys giggled and put a hand on Mettaton's nose, babbling. Mettaton smiled and booped the lizard's nose. Alphys giggled, before climbing into Mettaton's lap and putting her hands over his eyes.
"Where'd you go?" Mettaton asked, playing along. Alphys giggled and removed her hands. "Oh, there you are!" Mettaton chuckled. Alphys looked at Mettaton and giggled.
"D-Da…Da-Dada!" She cooed, placing a hand on Mettaton's cheek.
"D-Did she just call you what I think she did?" Undyne asked, holding back laughter.
"Oh for the love of Asgore did she…" Mettaton said, covering his face.
"Dada! Dada! Dada!" Alphys cooed, over and over again.
"This is humiliating…" Mettaton said, with a sigh.
"I guess you're Dada now!" Undyne said, doubling over with laughter.
"H-Hey! Shut up!" Mettaton snapped, causing Alphys to stop giggling. She looked at Mettaton and whimpered. "O-Oh, Alphy I'm sorry. D-Did I scare you?" Mettaton asked, picking Alphys up. Alphys burst into tears, burying her face into Mettaton's shoulder. Mettaton sighed and rocked her, hoping she would fall asleep. Of course it didn't take long until she did. Mettaton sat in a chair, holding the sleeping scientist. He sighed in relief. "Man, kids are hard to manage…" He said to himself.