Emrys remained silent for a moment.
Eventually, he let out a long sigh.
"Well. That's a lot to take in all at once, but I think I understand now."
Nimue turned her head slightly toward him.
"Does that mean you don't have any more questions?"
"What? Of course I do! I have tons of them!"
He raised his hands as though she had just accused him of something particularly absurd.
"I could probably spend the next ten years asking you questions and still never get to the end of them. But the main ones have been answered, so I can wait a little while before asking the rest."
He paused.
Then his expression changed.
Until now, he had mainly been trying to understand what had happened to his mother and why she was trapped in this place. Now that he had a clearer picture of the situation, another question naturally came to mind.
How could he get her out of here?
He turned toward her.
"The most important thing now is to find a way to get you out of here."
Nimue did not answer immediately. She listened attentively, but he sensed a slight change in her emotions.
"I might have an idea," he continued. "I could transport the lake into Unlimited Blade Works and then teleport you into the real world."
He raised a finger as though he had just presented the most obvious plan in the world.
"Well, it might not be exactly what you imagined when you talked about seeing the world with your own eyes, but it would be a good start. Once you're outside, we could look for a solution for what comes next."
He tilted his head.
"What do you think?"
Nimue remained still.
She had known for a long time that Emrys had never forgotten her dream. He had just reminded her of it once again, in his own characteristic way of immediately moving from identifying a problem to finding a solution.
He had not even finished processing all her revelations, and he was already looking for a way to give her what she had desired for millennia.
A warm feeling spread through her chest.
She would have liked to tell him that she liked his idea. That she was happy he had thought of it so quickly. That after all these years, knowing he still wanted to help her was almost enough to make the wait bearable.
But she could not allow him to get his hopes up for nothing.
"It won't be possible."
Emrys froze.
"... Excuse me?"
"Your plan won't work."
He remained silent for a few seconds, as though waiting for her to add something that would make her answer less categorical.
Nothing came.
"Why?"
Nimue took a breath before answering.
"If I understand how your ability works, when you want to move something into Unlimited Blade Works, the size of the object you wish to transport affects the amount of energy required to move it. The larger the object, the more energy it takes."
"Yes, that's right."
Emrys nodded. That was indeed one of the principles he had established through his experiments with his magic.
He still did not see where she was going with this.
Nimue placed a hand on the ground near the water's edge.
"Then think for a moment about what you're trying to move."
He frowned.
"The lake."
"Exactly. But do you actually know what this lake is?"
Emrys turned his head toward the expanse of water.
Although he did not know exactly what the lake was, Emrys was one hundred percent certain that it was not made of water. Neither its texture nor the magical energy it contained bore any resemblance to ordinary water.
He even suspected that the lake was actually a reservoir of magical energy so vast that its concentration had caused it to become visible.
"I've always wondered whether it was magical energy so dense that it had eventually become liquid," he said.
"That's exactly right."
He straightened slightly.
"Wait. Really?"
"Yes. The water you see isn't water in the usual sense of the word. It's pure magical energy, condensed to such an extent that it has acquired the properties of a liquid."
Nimue dipped her fingertips into the lake.
Small ripples spread around her hand before disappearing almost immediately.
"So you're saying that the lake contains so much magical energy that my current reserves aren't enough to transport it."
"Yes."
Emrys sighed deeply.
"That's a bit of a problem. I'll have to find a way to increase my magical energy reserves substantially. Training has its limits."
Nimue shook her head, dismissing Emrys's plans.
"No matter how much you increase your magical energy, it will never be enough to transport the entire lake."
"What do you mean?"
Nimue raised her head.
"Because the magical energy that makes up this lake is infinite."
Emrys stopped moving.
For a moment, he thought he had misheard her.
"... What?"
"Infinite, my dear."
He slowly turned his head toward the expanse of water.
Then toward his mother.
Then back toward the lake.
"Wait a second. Are you telling me that all of this..."
He gestured vaguely toward the water in front of them.
"... is infinite magical energy?"
"Yes."
"How is something like that even possible?"
Nimue smiled slightly.
But, contrary to what he had hoped, she did not answer.
Emrys waited a few seconds before realizing that she had no intention of providing him with any further explanation on the matter.
He sighed.
Of course.
He had just discovered that his mother was connected to an infinite reservoir of magical energy, and the only thing she could think to do was remain silent about how such a thing could exist.
He would have to get used to it.
"All right," he continued, "if the lake contains an infinite amount of magical energy, then creating a portal large enough to transport it would require..."
He stopped.
His expression gradually froze.
Nimue watched his reaction without intervening.
"An infinite amount of magical energy," he finished.
His shoulders slumped.
"Which I absolutely do not have."
"Exactly."
Emrys rubbed a hand over his face.
This is a problem.
He remained silent for a few seconds, allowing his thoughts to organize themselves.
Then another possibility occurred to him.
Wait... Do I really have to do it that way?
He raised his head.
"Mom, I might have another idea."
"I'm listening."
"Instead of transporting the lake directly, I could try to create a portal into Unlimited Blade Works. Then you could use the password to enter it yourself."
He accompanied his words with gestures, as though he were drawing the different stages of the plan in the air.
"I wouldn't need to move the entire expanse. I'd only need to create the passage. Once it was open, you could teleport inside using your own abilities. That should get around the problem of the amount of energy required to transport the lake, right?"
Nimue listened until he had finished.
Her expression did not change immediately, but Emrys sensed that she was seriously considering his proposal.
He waited.
"There are too many flaws in that plan," she finally said.
He grimaced.
"Of course. I should have expected that."
"It's not a bad idea in itself. But it raises several problems we cannot ignore."
She turned toward him.
"First, extend your Haki as far as you can."
Emrys raised an eyebrow.
"Now?"
"Yes. Trust me."
He did not ask any further questions.
He closed his eyes out of habit, even though doing so made no difference to his perception, and gradually released his Observation Haki.
His awareness spread around him.
He sensed the surface of the lake, the irregularities in its magical energy, the slightest movements nearby, and the silent immensity of the space surrounding him.
He continued extending his Haki.
One hundred meters.
One kilometer.
Ten kilometers.
He did not stop.
His perception stretched farther and farther, exceeding the distances at which most beings would have been able to maintain a coherent understanding of their surroundings.
One hundred kilometers.
Two hundred.
Three hundred.
He continued until he reached the limit of what he could perceive.
More than five hundred kilometers.
And yet...
Nothing.
Emrys frowned.
No matter how much he searched, extended his perception in every direction, or examined every detail he sensed, he could not find the lake's opposite shore.
There was no transition that would allow him to distinguish the end of the expanse of water.
No boundary.
No change indicating that the lake gave way to something else.
Only that same immensity, stretching beyond the reach of his Haki.
He slowly drew his perception back toward himself.
"I see."
Nimue tilted her head slightly.
"Judging by your expression, I think you've understood."
"The lake extends infinitely."
"That's the unfortunate reality."
She looked at the water in front of them.
"I don't even know whether another shore exists. I've never been able to reach a boundary, and nothing indicates that there is one."
Emrys remained silent.
He now understood why his mother had rejected his first plan.
Even if he managed to create a portal large enough, he would still have to surround the lake with swords in order to transfer it into Unlimited Blade Works. However, if the expanse was infinite, he could not reach its boundaries to establish such a perimeter.
He had no way to define the limits of something whose endpoint he could not even confirm existed.
"So surrounding the lake with swords is completely out of the question," he concluded.
"That's what I think."
He let out a sigh.
"All right. What's the second problem?"
Nimue calmly continued.
"Even if you managed to create the portal, I don't know what would happen if I used the lake's magical energy to transport the lake itself."
This time, she did not need to elaborate.
Emrys immediately understood what she meant.
He spent a few seconds thinking before slowly nodding.
"I see. It would be like trying to subtract infinity from infinity."
He crossed his arms.
"We have absolutely no idea what kind of paradox might occur."
The problem was more serious than it appeared.
If Nimue used the lake's magical energy to move the lake itself, they could not simply assume that the amount of energy would remain the same. They did not know whether the process would alter the nature of that energy, trigger an unpredictable reaction, or make the transfer itself impossible.
They had no rules that would allow them to predict the outcome.
And Emrys had no intention of risking his mother's freedom on an experiment whose consequences no one could anticipate.
"All right," he said. "I suppose there's a third problem."
"Indeed."
"Let me guess..."
Nimue opened her mouth, but he raised a hand to interrupt her.
"No, wait. I think I can figure this one out myself."
He took a moment to think.
Even if, by some miracle, they managed to overcome the first two obstacles, another obvious difficulty remained.
"Let's assume everything goes well. I manage to create the portal, you succeed in transporting the lake, and we end up inside Unlimited Blade Works. What happens next?"
He gestured toward the expanse of water.
"I don't even know whether Unlimited Blade Works is actually infinite. And even if it is, not all infinities are necessarily the same size."
He paused.
"The lake's infinity could be greater than the infinity of Unlimited Blade Works. Or Unlimited Blade Works might not be infinite at all. Either way, we'd have a problem."
Nimue smiled.
"Exactly."
Emrys tilted his head back and let out a long sigh.
"Great. Just great."
He remained still for a moment, his arms crossed, contemplating the scale of the problem.
He had started this conversation thinking that all he needed was to find a way to move his mother out of this place.
Now, he was discovering that the task involved an infinite amount of magical energy, an expanse whose boundaries he could not reach, and mathematical problems whose consequences were impossible to predict.
He would almost have preferred to fight a Superior Demon.
At least when he fought an opponent, he could try to understand their abilities, identify their weaknesses, and adapt his strategy.
Here, he did not even have a target to hit.
"I'm going to have to add a new concept to my list of things that are too complicated for me to bother understanding."
Nimue turned her head toward him.
"Your list?"
"Yes, my list."
"And what's already on it?"
Emrys answered without hesitation.
"Time."
She looked at him for a few seconds.
Then she burst out laughing.
It was not mocking laughter. Rather, it was the laughter of someone who had just discovered a new side of someone she had known her entire life.
"Time? Have you really decided not to try to understand time?"
"Absolutely. I already have enough problems as it is. I refuse to add something that might give me a headache for the next thousand years. Although, more specifically, it's time travel that pisses me off."
"Language."
He ran his hands over his hood and massaged his temples.
"Just thinking about it annoys me. And now I have to add the different types of infinity to that list. I have a feeling I'll eventually end up putting half the universe on it."
Nimue continued laughing for a few moments before calming down.
She placed a hand on his arm.
"In that case, what are you planning to do now, my dear?"
Emrys turned his head toward the lake once again.
His expression grew more serious.
Despite his jokes, he had no intention of giving up. He had waited nearly forty years to find his mother, and he certainly wasn't going to accept leaving her trapped here after finally being reunited with her.
If he couldn't move the lake, he would have to find another solution.
And, for once, that solution would not involve working around the problem.
He would have to tackle it at its source.
"Let's move on to Plan B."
Nimue tilted her head slightly.
"And what exactly is Plan B?"
Emrys straightened up and turned his face toward her.
"Regain my sight and absorb the entire lake."