The patter of footsteps sounded through the cavern. Asriel turned around to acknowledge Frisk.
They looked slightly out of breath, but not tired at all. The long day hadn't broken them. It hadn't even touched them.
"Frisk."
They said nothing.
"Don't worry about me."
And then, both at the same time, "Someone has to take care of these flowers."
The timing, the pacing, the tone were so perfectly aligned that it took him a moment to realize what had happened. They didn't just know what he was going to say, they had anticipated it perfectly.
He realized what that meant. A sinking feeling hit his stomach. His smile, not too steady in the first place, wavered.
"How… how many…"
"Please come with me. I know what to do."
"Frisk. I can't let anyone see me."
"I know. There's time to explain, but there's no time to stand around while I do it, so can we please get going?"
"Frisk -"
"We both know how this works. Can't we just skip ahead and pretend I already figured out what to say?"
It would happen, wouldn't it? Frisk would go back, and try again. They would try again, and again, until they found the right thing to convince him. They would become ever more experienced, but he would start from zero every time.
He motioned for Frisk to lead the way. They headed into the ruins at a brisk pace, and he followed.
But if this was the argument that convinced him, then how did that work? He might as well go along with Frisk, because eventually they'd come up with the argument that he might as well go along with Frisk, because -
"So." Frisk was no longer agitated. They were speaking carefully, almost lecturing. "You may have noticed that some things in the underground don't work the way they should."
"Like what?"
"Like the way people keep saying the same things, the same way, every time."
"That's just what happens when you reset."
"People are chaotic. If you start a conversation just a little differently, it keeps being different, and it keeps getting more different. But not here. Here, conversations are determined to stay on track. There are only so many lines of dialogue."
They climbed the stairs to the entrance of the ruins proper.
"I think conversations in Mount Ebott are cached. If someone gave an appropriate response before, in a similar situation, the world doesn't allow them to make a new one. They just do what they did before."
Together, they pressed the buttons on the floor. Asriel pulled the lever.
"It works fine, unless you pay attention. And there is more like that. A lot more. This world is lazy. It cuts corners. Speaking of which." They gestured around. "How do you think walls work? If you push into a wall, why doesn't it let you through?"
He should know this. "There's a, uh, normal force. You push on the molecules in the wall and they push back."
Frisk nodded. "That's how it should be, but it's pretty complicated, isn't it? Keeping track of all those molecules would be a lot of work. Now, the only things a wall really needs to do is to look like a wall, so you can't see through it, and to block things from moving through it."
They reached a bridge with spikes. Frisk ignored it, and carefully stepped onto the narrow ledge between the water and the wall.
"But there's no reason for walls that look different to always behave differently. So the simplest thing to do would be to separate those functions, and that's what happens here. There are things that look like walls, and there are things that stop you from moving, and usually, both of them are in the same place. But not always." They reached up and felt around the wall. "Sometimes there are mistakes. And that's why you can do this."
Their hands found the right spot, and their fingers reached through the bricks. The bricks didn't move, but Frisk's hand appeared cut off where the wall began. They pulled themself up, and soon only their feet were sticking out.
They were still easy to hear, even through the wall. "You can come up now, just mind the drop."
Asriel's head poked through the wall. It turned out to be wafer-thin. There was a short plateau to crawl over, but behind that, there was nothing. Only a black void, interrupted by rooms. The walls were somehow transparent from the outside. He looked at a Froggit, but it couldn't look back.
"This place is useful for getting around quickly. And it stops people from seeing you, of course."
"Where are we going?"
"We're going to Hotland. The underground isn't laid out the way it looks from the inside, so it's a short trip. I tried to make a map once, but it didn't fit together the way a map should."
They walked through the darkness. Their footsteps didn't make any sound.
The CORE loomed in the distance. After a few minutes they reached a studio, with a kitchen.
"Hey, what happened here, anyway? Didn't Mettaton have something planned? Did you just - skip it?"
"I did. And now we're going to go back to it, and let it happen. We just need to get close enough."
When they came near a small counter with a can on it - still outside ordinary space - Frisk's phone started to ring. Mettaton appeared inside the studio, and held an incoherent spiel about ingredients with Alphys.
"Now hold on tight."
The phone unfolded into a jetpack. Asriel grabbed Frisk's arm just in time before they sped away.
He had questions.
"That's - aren't they supposed to be somewhere else? What just happened?"
"They were somewhere else, but they were also there. The world knows that the first time I go near that location, Mettaton unveils his challenge and Alphys turns my phone into a jetpack. So that's what happens, even if Alphys and Mettaton are doing other things at the same time."
Aiming the jetpack horizontally allowed it to reach terrifying speeds. They were heading back to the cavern with the golden flowers.
"Almost there now."
They went straight through the wall, which turned out to be incorporeal at a height of twenty feet. They were moving up now, into the hole in the ceiling, no longer blocked by the barrier. The jetpack gave out just as they went through, and they dropped to the ground around the edge.
Frisk was the first to get up. "Okay. We need to keep moving."
Asriel scrambled to follow them. "Why are we here? What's your plan?"
"We needed to go to the surface, fast, without being seen. There are only two exits, and the other one is populated."
They reached the cave opening. It was still dark. The surface landscape stretched out as far as the eye could see. His breath stopped.
After ten seconds, Frisk pulled his sleeve to keep him moving.
"Sorry. I needed a moment. It's been a hundred years. But it feels longer."
"It's really important we keep moving. Unless we do something, you're going to turn back soon."
They started walking downhill.
"The things we just did were possible because of abstraction. All the finer details of the world are simplified, to something that should still work the same way. But sometimes it doesn't work the same way, and we can take advantage of that."
They came to a fork in the road. Frisk picked a path without hesitating.
"You don't have enough power to maintain this form, but that's not how the world makes it work. When it comes down to it, all that matters is that you turn back when your time runs out. So that's what happens. On 5:48 AM, on this date, you turn into a flower."
Asriel didn't know what time it was, but he could feel his energy running out.
They stopped at a row of widely spaced markers. "This is the border between the Principality of Ebott and Greater Arpinc. It's also a border between time zones."
"You mean -"
"Over here, it's 5:46 AM. Over there, it's 6:46 AM."
"That just makes me turn back sooner!"
"Not quite. You don't turn after 5:48 AM. You turn on 5:48 AM. If you cross the border now, you skip that entirely."
Asriel braced himself. "Here goes." He stepped across the border.
He immediately felt the effect. The feeling of energy in his chest dropped abruptly, so steeply that it went deep into the negative.
And nothing happened. It kept going down, but there was no limit to it. He didn't turn back. He stayed as he was.
"You need to stay here for a few more minutes," Frisk said, "until the moment passed on the Ebott side of the border. But I think you made it."
They sat there for a while, without talking, just listening to the sounds of the forest. The sun started to rise.
It was a beautiful day.