Author's Note:

To Eris: Thank you! I'm very happy you enjoyed your read. Here's the next chapter...

Teachings

Leonardo's head broke through the ocean's surface. He took a deep breath, narrowing his eyes to protect them from the sun.

Learning how to swim had been one of the best experiences in his life, and he spent all his free time exploring the coast. Unless, of course, the ocean was raging like it had the week before.

He left the water reluctantly. He would have gladly stayed there all day, but he didn't want to be late for his lesson with April.

He was too grateful to have her as his teacher for that.

As he had soon learned, the island was a center for knowledge amongst waterbenders. Promising young waterbenders were sent here to learn from the best masters in this part of the world. Leonardo wasn't sure he was qualified to be one of them, but April and the others had welcomed him after hearing his story.

Or part of his story. Everything he had told them was the truth - that he was the only waterbender in his oasis and there was no one to teach him, that he was eager to learn - but he had left in the dark the part where he could hear a being supposedly buried for two hundred years and be influenced by it…

He avoided thinking about that as much as he could.

Luckily, there were many opportunities for wonder and he hadn't much time to brood over. The island also welcomed scholars from other bending families, like Earth and Air, and witnessing their existence and their bending with his very own eyes had been a shock to Leonardo.

Casey was the only firebender at the moment, but according to April he hadn't been the first.

Leonardo's friend didn't seem to have any problem with it. These days, he was very busy trying to convince April to spend more time with him. He had managed to get private swimming lessons from her, but as far as Leonardo knew they weren't a couple.

The teenager reached the place on the beach where he had left his clothes and quickly dressed before entering the forest. It wouldn't be long before he arrived at the clearing where the buildings stood.

And indeed, barely ten minutes after he was seeing them. They were shaped like waves and sheltered apartments and classrooms. A monumental fountain stood in the center of the clearing, rocks in its basin allowing to stand as close to the water as possible.

It was a perfect place to teach waterbending.

The others students were already waiting on their respective rocks. Leonardo spotted April leaving the teachers' building and he hurried to avoid being late.

He jumped on his rock just in time for the beginning of the lesson.

April smiled at him as she took her place amongst them. She probably guessed where he had been - it was an open secret that Leonardo spent almost as much time in the water as he did on solid ground.

The lesson began, and Leonardo focused on learning.

He wasn't as advanced as the six other students, who were older than him and had been immersed in waterbending culture since they were born. April gave him private lessons to help him catch up, but she also thought it would be good for him to learn with the others, and therefore he attended several of their lessons.

She thought he was gifted and learned quickly, and Leonardo felt guilty he hadn't told her he already had some training.

He absolutely didn't want to remember who had helped him to find his first moves, and he was careful not to display anything April hadn't taught him first.

Leonardo watched the others as they all followed April's lead. Although he wouldn't have named any of the other students his friend, they were rather nice to him.

Except from one, who was a little too condescending for Leonardo's taste. In several occasions, he had made remarks implying that the waterbender from the desert was a bumpkin.

Leonardo felt it was easier to ignore it. He had secretly nicknamed the arrogant student Fishface, because his rounded head reminded him of a kind of bloated fish he saw a lot underwater.

To Leonardo's slight irritation, Fishface happened to be the most promising of the already promising students.

Well. At least he wasn't half as bad as Slash was, if what Raphael had said was true.

And Leonardo had no doubt it was.

His thoughts drifted towards his twin. How was Raphael doing? What had their father told him? Leonardo knew Yoshi hadn't had any intention of telling his family the truth while Bishop was still there, but it had been several weeks since the teenager had left his home. Surely the caliphe's delegate was gone by now, and his mother and brothers didn't think Leonardo was lost to them forever.

"Leonardo? Are you with us?"

April's voice brought him back to reality, and he realized with embarrassment that he had suspended his move and had been holding a water bubble above his head for way too long.

Fishface was smirking, and several other students were failing at hiding their grins.

Leonardo blushed.

"Sorry," he muttered, quickly shaping the water into a liquid vine and coiling it around his body like the others already had.

April accepted his apology with a nod and went on with the lesson.

Leonardo took a deep breath, promising himself that he wouldn't let his thoughts drift away again.

He needed to do his best and learn fast, so he could come back to his family as soon as possible.

For as much as he enjoyed this amazing place, it could never be his home without the people he loved with all his heart.

That night, Leonardo couldn't find sleep. All the thoughts he had managed to keep at bay during the day came back to nag at him.

His concern. His doubts. His homesickness.

Leonardo gave up after an hour of tossing and turning in his bed. He decided that a short walk outside would do him good, and sneaked out of his room.

The students' building was oddly silent, and Leonardo wondered whether they were having a special lesson tonight.

Leonardo shrugged. Even if it was the case, April hadn't invited him, which meant that it must be too advanced for him.

He took a few steps outside. Thanks to the full moon, he had no difficulty seeing where he was going. He made for the fountain and sat on one of the rocks, letting his fingers drift in the water.

The motion reminded him of the time he had spent inside his favorite cave, back at the oasis, and of that time when Raphael had surprised him playing with Karai.

His twin had been so concerned about people learning he was a waterbender, and now Leonardo could use his gifts openly, without fear of being caught…

Because you were exiled, a little voice said inside his head. So Raph was right, wasn't he?

"I would never have learned so much if I had stayed in the oasis," he said aloud to better shut it up.

Of course, he didn't expect any answer. So when the rock he was sitting on trembled and a blue light drew a wavy shape in the fountain's basin, Leonardo froze in surprise.

Then he realized that his fist had clenched in the water. Had he triggered a mechanism of some kind? Was it because of the moon, which now lighted an open door inside the sculpture at the center of the fountain?

Leonardo had examined this sculpture before - it represented three giant animals April had named whales, animals Leonardo had never seen in his life - and it certainly didn't have any door.

In the eerie silence, Leonardo jumped from rock to rock to reach the opening. He could see the beginning of a staircase.

He looked around to check if someone was there, and as he didn't see anybody, he made his decision and began going down the stairs.

For a tunnel opening in a fountain, it was remarkably dry.

It was also longer than Leonardo had anticipated. He lost track of time as he went down, then up as the stairs changed direction. Slits in the wall gave a pale white light like moonlight slivers and allowed Leonardo to see where he was setting foot.

He felt more excited than afraid. As nobody had told him about this place, nobody had forbidden him to go there - and thus he didn't think he would be in major trouble if people found out.

Besides, it was the most familiar setting he had encountered so far - a feeling that was only confirmed when he entered a vast cave.

The salty air and the rustle of waves told Leonardo that the ocean was nearby moments before he saw the pool.

Although Leonardo could see the cave's ceiling, the full moon was reflected inside the pool, lighting the area brightly. Maybe there were mirrors guiding the light inside the cave?

Leonardo didn't have time to look for them before he realized that April and the other students were bent over this pool. He stopped, heart beating, and hid behind a stalagmite.

They didn't seem to have noticed him. They were in the lit area while he stood in the shadows, and he had been silent.

So this was a lesson? Should he go back unnoticed?

But now that he was there…

He pricked up his ears.

"Still water surface… Full moon…"

He grimaced. He was too far and could only hear bribes of what April was saying.

But there were several columns of limestone in the cave, created drop by drop by water dripping from the ceiling, and he could use it to his advantage.

Going from stalagmite to stalagmite, he managed to go close enough to hear April's talk.

"… The water can show you what you wish to see, or what you need to see, but it cannot invent. On nights like these, it's easier to channel the power to do so. Who wants to try first?"

Fishface volunteered, and Leonardo watched with interest as he joined his hands in deep concentration and fixed the pool like it held the answer to life, the universe and everything.

Leonardo counted 42 seconds of absolutely nothing happening before April spoke.

"Like I said, this is one of the trickiest skills to acquire, and in no way a requirement to become a master. Many great waterbenders could never read in the water, others reported that it happened to them once in a lifetime."

Fishface nodded. "Yes, Master April."

He sounded disappointed, though, and Leonardo felt almost sorry for him.

"Who wants to try next?" April asked.

Another student took Fishface's place. Fishface himself took a few steps away from the group, and Leonardo made himself as small as possible behind his stalagmite.

Why couldn't Fishface stay with the others? Not like anything seemed to happen as students took turns in trying to read the water - whatever it meant - but still.

Alas, Fishface didn't hear Leonardo's silent prayer. And despite Leonardo's best efforts, the inevitable happened.

"What the…" Fishface said, his eyes narrowing in Leonardo's direction. "Master April!" he shouted.

A few seconds later, a blushing Leonardo awkwardly explained himself to a very much unimpressed April.

"I… I couldn't sleep, and I sat on the fountain, and the door opened, and… uh…"

"You were curious." April sighed. "I can understand that, although I do not appreciate that you were spying on us."

Leonardo bit his lip. "Sorry."

"Well, now that you're here, you might as well stay." April waved at the pool. "This is a sacred place for our people, and one where water-reading is the most accessible."

Leonardo drank her every word.

"It remains a rare skill." April bent over the water and fell silent.

An image slowly formed inside the water, the picture of a shape asleep in a dark room. It wasn't possible to see the person's features, but right before the image quickly dissipated, Leonardo caught sight of a belt folded on a chair, a belt that looked suspiciously like Casey's.

Leonardo probably imagined the slight blush on April's cheeks, because her voice was as serene as ever as she commented.

"Sometimes you can direct your thoughts towards what you wish to see, and sometimes the water will show you something entirely different."

Leonardo watched the water surface, his heart beating. Was such a thing really possible? Could the water show him what he wanted to know, what he needed to know?

"Do you want to try?" April asked him.

Leonardo hesitated. He likely wouldn't see anything, like Fishface and the other students. But what if he did?

He nodded and took a step forwards. He had been dying to have news of his family ever since he had left the oasis.

Mikey… Donnie… Raph… Karai… Mom…

The water surface was as smooth as ever. Behind him, Fishface cleared his throat.

Leonardo ignored him.

Are they alright? Did they found out what happened to me?

He hadn't entirely realized it until now, but in that moment where it was almost possible - where he could finally have answers - Leonardo admitted to himself how much he missed them. His heart ached to see them again…

Please. I need to know.

A picture suddenly formed in the water below him. This time, Leonardo immediately recognized the protagonists - the sun was high in the sky and Karai, Angel, Donnie and Mikey were hiding behind a wall, Karai's hand over Michelangelo's mouth…

And Leonardo frowned, barely conscious of the gasps behind him. What were these four doing together? Why wasn't Raphael there? He couldn't have been training, or Angel would have been too. Unless they were playing some game of hide-and-seek? But then, hiding all in the same place wasn't the best move.

Before Leonardo could think about it any further, the scene changed. In a forest, Raphael was riding next to Slash, while Bishop talked to both of them…

Leonardo bent closer to the water, as if it could help him make sense of what he was seeing. What was Raphael doing with Bishop? And Slash? His brother couldn't stand Slash's presence. And why were the three of them in a forest and not at the oasis, or at the very least in the desert nearby?

Leonardo was so close to the water that his hands brushed its surface, and the scene changed once more. Now he was looking at a man standing on a battle field, a man throwing shards of ice in every direction, and people he hit collapsed on the ground…

And he dodged the fireballs sent his way by an ever-shrinking army of firebenders…

But it wasn't the grim scene that made Leonardo shout, nor the certainty that he was looking at the Shredder on his last day on the surface of this world…

It was the fact that he recognized his mother's features on the man's face.

"No!"

Then Leonardo's world went black.

Leonardo woke up in an unfamiliar bed. He blinked several times, confused, before he remembered what had happened.

The water had shown him his brothers, like he had wanted - Donatello and Michelangelo safe home, but Raphael away from them - and then the water had shown him something he hadn't wished for, something he didn't want to know…

The Shredder, looking familiar. The Shredder, resembling his mother.

The Shredder, his waterbender ancestor.

No.

"Awake?"

Leonardo laboriously turned his head towards the voice.

Casey was there, sitting in a chair next to the bed and watching over him.

"We were worried," he said with relief. "April said that you had exhausted yourself."

Leonardo wondered what exactly April had told Casey.

The man stood up. "I'll tell her you're awake, okay? Don't move."

Leonardo didn't reply that he couldn't have even if he had wanted to. He felt drained.

A moment later, April entered the room with Casey and sat on the chair.

"Hi, Leo," she said. "I'm glad you're awake."

"What… what happened?" Leonardo croaked.

April gave him a glass of water to drink.

"You exhausted your energy and fainted. To be honest, I didn't expect you to see anything in the water, let alone several times in a row." She smiled. "Casey told me you saw your family?"

So she must have told him in detail.

Leonardo averted his eyes. "Yes."

Including the last one, he thought bitterly.

"April said she saw you in a forest," Casey interjected. "It was Raph, right?"

Leonardo nodded, worry gnawing at his heart. "I have no idea what he's doing in this place. He had no reason to leave the oasis."

Casey looked worried as he nodded. "I'm sure he's safe," he said for Leonardo's sake. He paused. "And that last man… I can only guess, but I think it was the Shredder."

April's face darkened. "That man… I've read the stories. His was a dark soul. Throwing shards of ice was his preferred way of fighting, which is why he was nicknamed the Shredder." She looked in the distance. "He studied on this island in his youth. He's described as a handsome and charismatic student, avid to learn although a bit arrogant."

Leonardo's eyes slightly widened at the news. So the Shredder had studied there too?

April sighed. "Nobody could have guessed how bad he turned as he got older. I've been told you know the story of how he took over your oasis and was defeated by your people." She watched Leonardo pensively. "I wonder why the water showed him to you."

Leonardo tensed under the bed sheets.

"I don't know," he said weakly.

And while it wasn't entirely false, it wasn't entirely true, either. But Leonardo didn't want to talk about it - because then it would become an even more tangible reality.

His secret was safe for now. Casey would have recognized Tang Shen's features in this sworn enemy, but Casey hadn't been there, and April had never seen Leonardo's mother.

April smiled reassuringly. "Maybe the water absorbed your curiosity. After all, it was probably the last time waterbending happened in your home." She caught Leonardo's anxious gaze and patted the mattress. "I'm sorry you were introduced to waterbending with such a gruesome story. I hope you know most of us aren't power-hungry beings like him, right? Including you."

Leonardo nodded and yawned, hoping she and Casey would leave him soon. He didn't know how long he would be able to hold back his tears.

Luckily, April took the hint. "Now you rest and recharge." She stood up. "Call if you need anything, alright?"

Leonardo nodded again, unable to tell her that they couldn't give him what he really needed.

To never have learned about the Shredder's link to him.