The thing about being a five-year-old with five hundred and ninety-six years of memories was that sitting through a lesson about the letter G felt like a very specific kind of torture.

  Lark sat at his table with his chin in his hand and stared at the alphabet chart on the wall while the real, actual, working part of his brain ran circles around a problem that had been gnawing at him since breakfast.

  How do you wake up a Core in a world that barely has any Aether in it?

  Aether was everything. That was the first thing any cultivator learned, usually from someone older and more patient than Lark had ever been. It wasn't some external force you pulled out of thin air. It was you. It was the thing inside every living being that made them alive in the first place. The soul. The life force. The part of a person that lingered in an empty room after someone left and made the air feel different. Every person carried it. Most animals did too. Even old trees held traces of it in their roots.

  But Aether on its own didn't do much. It sat inside a person the way water sat in a sealed jar. Present. Doing its job. Keeping you breathing and moving and warm. But it couldn't grow. Couldn't be shaped. Couldn't become anything beyond what it already was.

  That's where the Core comes in.

  A Core was a structure, something rare and crystallized deep inside the soul at birth, most people never knowing they had one and never would. With a Core, the Aether inside you could be directed. It could resonate with something larger than itself, respond to the deepest truth of who you were. That truth was the Path. Not something chosen. Not something studied for. Just the loudest thing a soul had always been, finally given a direction to run.

  Grow the Core and the existence itself grew. Walk the Path, and being alive stopped being just that and started becoming something else entirely. Something stronger. Something that didn't have an easy word for it yet, at least not in any language this root world had come up with.

  That's cultivation. The whole thing. Just that.

  The problem was getting started. Activating a Core the normal way needed a massive external surge of Aether, enough to shake the dormant Core awake and get it to recognize itself. Root worlds didn't have that. This one especially. The Aether concentration here was barely a whisper. Background noise. The reason Lark's Core had woken up the first time was because something enormous had crashed through the sky from an upper realm and dragged a tidal wave of Aether with it that hit everything all at once.

  The narrative has been taken without permission. Report any sightings.

  Can't wait for that. Can't cause that. So what does have Aether?

  He sat up straighter.

  Other Cores. If I could find a Core, even one from a creature, the concentrated Aether inside it might be enough to trigger mine. It wouldn't change my Path. That's mine, embedded in my soul, nothing touches that. But a better Core could replace my Common one and the difference in how fast I could actually cultivate would be enormous. Five hundred and ninety-six years dragging myself uphill with a Common Core. Even a Refined one would cut that time down significantly.

  He was grinning before he noticed.

  "What are you smiling at?"

  He looked up. Two boys had materialized next to his table with the energy of people who had been looking for any excuse to stop doing their worksheets. Mark was the tall one, broad even at five, with a friendly open face and the kind of calm that made adults relax without knowing why. Reynor was already spinning a pencil between his fingers, eyes sharp and restless, the human equivalent of a question that hadn't decided what it was asking yet.

  "Nothing," Lark said.

  "You were smiling at the paper," Reynor said. "The letter G. What did G do?"

  "I wasn't smiling at the paper."

  "You were looking right at it."

  "I was thinking."

  "You think weird," Reynor said. He said it without any meanness, just as a fact.

  Mark sat sideways in the empty chair next to Lark. "Big tree after lunch?"

  "Yeah," Lark said.

  He looked at the two of them. Mark, who would grow up steady and reliable in a way most people never managed. Reynor, who would make every single day louder and more interesting and occasionally dangerous. He'd lost track of them after elementary school. And then the world had ended, and then five hundred and ninety-six years had happened, and somewhere in all of that these two had just become a memory of something warm he hadn't known he'd missed.

  Do either of them have a Core? The thought surfaced before he could stop it. Mark's got that grounded quality. And Reynor, that fixation of his, the way he locks onto something and doesn't let go. That could go Overbearing. Could go Demonic.

  He cut the thought off.

  No. Stop. They're five. You're five. Get strong first. Everything else comes later.

  "Whatcha thinking?" Reynor asked.

  "About letters."

  "The letter G?"

  "I’m thinking of using it."

  "Huh?" Reynor looked confused. "Anyway. Big tree. Lunch. You coming or not?"

  "I'm coming," Lark said. Then, because the thought had been sitting in the back of his head all morning and it had to go somewhere, he said, "Hey. Where do you think the school ghosts actually are? Like, where do they live?"

  Reynor's pencil stopped spinning. Mark leaned forward.

  Lark had their full attention.