Understay - an Undertale Fanfic

Understay XII - Reunited

A day passed. Frisk was happy.

A week passed. Frisk made spaghetti. Papyrus was happy.

A month passed. Frisk sparred against Mettaton. The viewers were happy.

A year passed. Frisk had a birthday, and tried snail pie. Toriel was happy.

More years passed. Frisk matured, growing both mentally and physically. He resembled a boss monster in all but Soul, and even that wasn't quite human thanks to Asriel. His parents were happy, but... they were slowing down. They ached from simpler tasks. They were concerned. The three of them were paying a visit to Alphys once more, to see if she could figure out the cause. Asgore knocked on the lab's door, Toriel and Frisk stood behind him. Alphys was quick to open the door.

"G-good morning, your majesties." She nodded a quick greeting, ducking out of the way to let them in. "Th-this is about yesterday's call, right?"

"Indeed." Asgore nodded as he entered. "Both Toriel and I are feeling the same symptoms."

"Wh-what symptoms?"

"We feel stiff." Toriel replied, taking a seat. "Things are just... harder."

"Harder how?" Alphys frowned, getting a clipboard and starting to write.

"Our joints are a little stiffer." Asgore added. "My wife's vision is worsening, I don't believe I'm as strong as I used to be, we keep forgetting little things..."

"How's your magic?" Alphys asked, glancing up from over her clipboard.

"That, at least, is unaffected." Toriel replied. Asgore nodded, holding a hand out and summoning a fireball to demonstrate.

"Yeah, that looks okay... Frisk, have you noticed anything like that?"

"Nu-uh." Frisk shook his head. He and Asriel had felt fine, save for the odd growing pain.

"So it's not disease, at least... wait, hang on." Alphys looked at her notes, then at Frisk, then the standing Asgore. "Frisk, you've grown up, huh?" Alphys chuckled awkwardly. "You're looking like a true boss monster now."

"Alphys?" Asgore frowned a little.

"Well, um, it... it may just be that you two have started ageing again."

-----

"Oh?" Toriel asked. "It's true that we have a child again, but I did not think Frisk would be able to trigger that reaction..."

"He probably hasn't, um, it may be Asriel living in Frisk that's getting your strength." Asgore and Toriel exchanged nervous glances. "I, um, I guess the clock is ticking again." Alphys looked at the floor. "I-I don't know how long boss monsters live for, but, um... you, uh, you may want to sort things out, uh, I'm... I'm sorry."

"... thank you, doctor Alphys. If nothing else, you've helped set our minds at ease." Toriel nodded, getting up again.

"I, uh, I think you'll have a few years still. I, uh, i-if there's anything else I can help with, I, I'll do my best..."

"We'll let you know." Asgore nodded gently, sighing softly. "I have had a long reign anyway. It will be nice to get some peace and quiet." Frisk was distraught from this news. They were ageing? It was foolish to assume he would have been able to live with them forever, but it had only been a few years. He just wanted more time. To make matters worse, they were only ageing because of him. He considered running away, considered distancing himself for their sake, but Asgore distracted him from these thoughts. "It's alright, Frisk. Boss monsters have always aged like this, for as long as there have been boss monsters. Of course, I can see why you feel as you do, but..." he sighed, trying to figure out how to say what was on his mind. "Honestly, I'd be grateful for a peaceful death, happy in the knowledge that you are going to be my legacy." He hugged him, gently yet firmly. Toriel did the same, gently stroking the back of his head. Frisk sniffled, trying to control the tears.