"So, how are we going to get Asriel his body back?" Chara asked.
"We need to get him another soul," Frisk replied. They turned their eyes and face upward. "Technically, any soul will do. Once a soul binds with an essence, the body belonging to that essence will take form. Or, at least, that's what Alphys has been telling me."
"What do you mean, 'any soul'?"
"In theory, there are only two types of souls in the world: human souls, and monster souls. Obviously, we'll need to get Asriel a monster soul, as his essence won't accept a human soul. But, well, souls don't just grow on trees. There's exactly one soul for every living being in the world, so there's no way for us to ever get another 'free' soul without...forcefully taking it from something else."
"Huh."
Chara stretched themselves out on their bed, sighing. The two birds were hopping around Asriel's flower pot, making chirping noises. Every once in a while, Asriel's face would appear on the flower and make a scary face to frighten the little birds. He would always laugh as he watched the two birds run back into their cages.
Frisk had to admit, the whole thing did look kind of funny.
"At this rate, I might as well just give up," Asriel spoke up. "Let's face it: I'm never going to get my soul, or my body, back. I'm going to be a flower forever."
"Don't say that," Chara said.
"No, it's fine, really. I've kind of gotten accustomed to being a flower. It's not that bad once you get used to it."
"That's a depressing thing to say."
Frisk couldn't help feeling sorry for Asriel. No matter what, they would not stop trying to find a way to get Asriel his body back, even if he didn't mind being a flower. They knew that Alphys had been working hard on researching monster souls. Sans had been helping her out as well. One day, they would have to make a breakthrough. They had to.
In the meantime, Frisk had returned to their days of reading and studying on the university campus, while Chara went back to their piano lessons with Undyne and evening games with Alphys. Except lately, Alphys had become so busy working that Chara ended up having to play games by themselves. Today, Frisk had decided to keep Chara company. They were sitting on their bed, reading a book on the possible geographical origins of monsters, while Chara was playing another rage-inducing game which, ironically, also had the word 'Souls' in its title.
Frisk was interrupted from their reading by Chara angrily throwing their controller down onto their bed.
"That has to be the least fair boss I've ever fought!" Chara shouted at the monitor. "You can't just attack me forever like that!"
"You're losing because you don't have any patience," Asriel said, pointing a leaf-like finger at Chara. "Look. I've been watching you play. You keep getting caught by that third swipe because you don't time your dodges correctly."
"I'd time it right if I had a moment to dodge at all!"
With a flirtatious smile, Frisk leaned towards Chara and placed an arm around their shoulder. "How about you let me try?"
"You're going to get destroyed, Frisk."
"I'll show you how good I am!"
Frisk took the controller into their hands, ignoring Chara. As the character in the game respawned, Chara smiled sarcastically and leaned their head against Frisk. The scent of Chara's hair momentarily made Frisk feel warm and dreamy. However, Frisk had a statement to prove, so they continued ignoring Chara and began running back to the boss.
Chara's phone on the table rang. They got up and answered the call. Moments later, right before Frisk entered the boss's room, Chara hung up and rushed back to the bed.
"Alphys is telling us to go downstairs to her laboratory. She says to bring Asriel."
Frisk's hands froze. "What? Really?"
"Yeah! Let's go right now!"
"Okay."
"I wonder what it could be this time," Asriel muttered.
With Chara holding Asriel's flower pot, the three of them went out of their apartment and descended on the elevator down to Alphys's laboratory. When the elevator doors opened, Frisk was surprised to find that the River Person was there.
"Long time no see!" Chara exclaimed when they saw the River Person.
"Yeah. We haven't visited your cafe ever since we moved back here," Frisk said. "Sorry about that."
"It's quite all right," the River Person replied. "Actually, I am closing down my cafe. Furthermore, this shall probably be the last time that you will ever see me again."
Frisk's smile transformed into an enormous frown. "But why?"
"I am here to help Asriel get his body back," the River Person said.
"He's r-right," Alphys chimed in. "We've figured out a way to m-make Asriel another soul. The key lies in the Core and in the River Person." She lowered her head and her expression became downcast. "They're really quite s-selfless."
The River Person made a sound like a laugh. Something gleamed from behind their hood. "I believe I've told you how I came to take this form, yes?"
Both Frisk and Chara nodded.
"When my former self fell into the Core long ago, two new monsters were created, and what remained of my shattered Soul used the power of the Core to construct this new form. That means I am not a body at all, but rather a walking, breathing soul, powered by magic. To be frank, I am quite done with this form. My essence lives on in my two descendants, so I am ready to discard this self. In other words, I am willing to give my soul to Asriel."
"And the c-catalyst is the Core," Alphys said. "With the tremendous magical energy residing within it, we can p-purify the River Person's soul, then bind Asriel's essence to it. The result will be a s-soul with a body restored to its true form. Asriel's form."
Frisk didn't know what to say. They didn't want to say that they were glad that the River Person was willing to make this sacrifice. But, deep down, they knew why the River Person was doing it. Chara probably understood why, too.
The River Person's task was complete. They did not desire to exist for any longer, so they would make their final act be to save another person, something that only they could do.
"Well, shall we get going?" the River Person said.
"Wait," Chara said. "Didn't Killer drain all the magical energy from the Core? Isn't that place just an empty tunnel right now?"
"That's c-correct. We'll have to use a Core from another world," Alphys said, sweat falling from her brow. "So to do this, we n-need to enter another timeline."
"Seriously?"
"Yeah. I've already f-found the nearest timeline that we can get to by following the tunnels. I don't think anyone in that timeline will r-really mind us intruding to use their Core's power. We only need about a minute."
"I hate the thought of going back down there."
"Me too," Frisk said.
"Killer is dead," the River Person said. "We have explored and mapped out the tunnels thoroughly. There is nothing down there anymore."
"In that case, what are waiting for?" Asriel spoke up, a large grin appearing on the flower's face. "Come on, let's go already!"
"He's right," Alphys said. "I can't imagine h-how long you've been waiting to get your body back. Let's not w-waste anymore time!"
"Okay. Let's do it," Chara said.
Frisk nodded.
The five of them, together, went back down into the tunnels underneath the laboratory. Memories of their final fight against Killer, when the walls of the tunnels had been swarming with shadows, came flooding back to Frisk's mind. For a moment, they paused, stricken with fear.
Chara took Frisk's hand.
"It's okay," Chara said, their red eyes staring deeply into Frisk's. "There's nothing for us to worry about."
"Thanks," Frisk responded, gripping Chara's hand tightly. They tried to smile. "I was just reminded of Killer's shadows for a second."
"To be h-honest, who wouldn't be?" Alphys said. "That was one scary b-battle!"
"Yeah," Chara said, laughing out loud. "Really, though – they're dead, right?"
"Of course. With our combined determination, we eliminated them," the River Person said.
"Exactly. Come on, Frisk. Asriel's waiting!"
After walking through the tunnels for about an hour, they began to see a bright light shining out from the hall ahead. As they walked into the light, Frisk was instantly reminded of their own journey through the Core of the underground. The smell of chrome filled the air. But, unlike before, there were no monsters trying to kill them this time. And no Mettaton waiting for them at the end, either. Unless, for some reason, there was...?
"We're in t-timeline number two thousand six hundred and ninety-three," Alphys said. "It's one of the timelines that s-survived. I believe all the monsters have already m-made it to the surface in this one."
"Did we really cross into another timeline just by walking into it?" Frisk asked.
"That is the power of the Core," the River Person said. "Or, more precisely, it is the fact that most of the timelines split at the exact moment that I fell into the Core so long ago. All of those timelines converge at this one point."
"So, r-really, when you enter one Core, you actually enter the Core of every timeline," Alphys said. "The exceptions are the timelines where the Core h-has been drained of all its power. The physics behind how those t-timelines connect with each other is really complicated, but I can explain it to you if you want-"
"It's fine," Chara said. "I think Asriel just wants to get his body back."
"R-right!"
After walking for a bit longer, they finally arrived onto the bridge where Frisk had fought Mettaton. But where there had been walls before, there was now just empty space. Far beneath the bridge was a vast and glowing sea of magical energy.
"We came here earlier, and tinkled with the m-machinery, so the Core here has been exposed," Alphys said. "Everyone, stay back. We really don't want any of you falling in, which w-would potentially create even more timelines!"
"Except for me," the River Person said, stepping onto the bridge. "I will fall into the Core again. This time, I will purge this soul of my essence. Then, you will fetch me out and allow my soul to enter Asriel."
"How are we going to do that?" Chara asked.
"With this, of course!" Alphys said. She took out a long stretch of rope from inside her lab coat and smiled. "You'd be surprised at how g-good a simple rope can be at lifting up a soul!"
Frisk stared at Alphys as she tied the rope around the River Person's body. They were really finding this plan hard to believe, but if both Alphys and the River Person trusted it...
The River Person stepped towards the edge of the bridge.
"Farewell, everyone," the River Person said. "It has been a pleasure."
Frisk felt themselves growing teary-eyed. "River Person. Thank you for saving me back then. I really owe you my life."
"I was merely doing my job."
Chara wiped their eyes with their hand. "You don't know how much saving Frisk meant to me! I didn't trust you at first, but now, really, y-you're – you're one of my friends, you know?"
For a split second, Frisk thought they saw a glimmer at the edge of the River Person's hood. A glimmer, and just the silhouette of a soft, genuine smile.
"Thank you, Chara. Thank you, Frisk," the River Person said. "The two of you are my friends, too."
Chara placed Asriel's pot on the ground and turned away, covering their face with their hand. Frisk placed a hand on Chara's back, but they could not help but lower their face as well. Something wet was about to fall from their eyes.
"Let's d-do it," Alphys said, sniffing. "Let's give Asriel his body back."
The River Person nodded. "Here I go."
They jumped off the bridge, raising their hands to wave at Frisk and Chara one final time.
A second later, there was a bright flash of light. So bright, in fact, that Frisk was momentarily blinded. Their vision went white, and even when they shut their eyes they could see an almost burning redness.
They heard a sound like an explosion, and then something like a hard rustling. The light dimmed, and they opened their eyes to see Alphys hauling up a bright, glowing ball on her rope. The ball was so bright that it stung Frisk's eyes just to look at it.
It was a soul in its purest form, bound to no creature's essence.
Alphys walked towards Asriel with her head turned away from the blindingly bright light. Once she was close enough, she transferred the soul onto Asriel's flower.
There was another bright flash of light.
Once everything had dimmed down again, Frisk opened up their eyes.
The pot had spilled over. Clumps of soil lay on the ground. There was no flower anywhere.
Standing in front of them, just like Frisk had seen on that day when the barrier to the surface shattered, was a small goat boy in a green and yellow-striped sweater.
Chara stretched out their arms.
But, to Frisk's surprise, Asriel simply stood there.
"All right, I'll give you all a hug," Asriel said in an oddly indifferent tone of voice. "First thing I'm going to do when we get back, though –" he stared at Chara "– I'm going to show you that I can beat all your games!"