"—wow. That must suck, to take that long to grow up."

Bounce bounce bounce - "it's the worst. I ran away to Tol Eressea and then I ran away to the Outer Lands because I didn't want to take that long and then I got an interdimensional teleport and now they can't make me go back."

"Do you grow up faster when not wherever you're from?" (Barbra and the older children decide not to hover around the "kids" since they seem to be hitting it off, and go elsewhere—but still nearby.) "How long would you take to grow up here?"

"Yeah, everything grows ten times as slow in Valinor because Valinor's supposed to be blissful and slow and stuff. It'd only take me fifty years here."

"Fifty years—that's still a lot—"

"I know."

"How'd you get here? What powers do you have? How'd you make Behemoth go away? Are there other demons that could help?"

"There are other demons but I got lost getting here and don't know how to find my way back to them. Demons are indestructible and can make anything that's made out of atoms, except people and animals, if we try making people they come out braindead. I also have a teleport and a healing spell because you can give people those in the place I'm from, and I'm an Elf so I can do some things humans can't do."

"What things? Could you give anyone a healing spell?—is it magic? Can't you use magic to grow up faster?"

"I could have used magic to make myself look grownup but I'd still have the emotional maturity of a fourteen-year-old Elf which is like a six or seven year old human and my Boots thought it might be a bad idea to do that."

"Do Elves mature more slowly, too? Can't you do magic to fix that? Humans mature faster and we're alright."

"I could probably do something but I'm not sure it'd be exactly 'making me mature faster' - like, I could change my impulse control or my time preference or whatever, but I'd feel kind of weird about that - and I don't want to lose my neuroplasticity, that bit's great."

"Neuroplasticity? That thing where kids learn things faster? Yeah I don't wanna lose that either."

Grin. "I'm so good at languages. They were talking about making me go to school and I said I'd go learn languages if they wanted."

"You can skip school? I wanna skip school, too! It's so boring and the kids there are always terrible to me and I don't learn anything I learn so much faster on my own—"

"I'm not sure if they're letting me skip because I have a teleport and they really couldn't make me go, or because I'm technically a hundred twenty two and a half, or because I pointed out to Legend that if they taught computer science or electrical engineering or something in school I wouldn't learn anything because your world's behind mine and then he was sort of like 'okay'."

"—you know that stuff? Can you teach me? All people teach in school is how to read or multiplication like I'm dumb or something."

"It's really good they aren't making me go I think I'd be really annoying. Anyway, yeah, you hafta know a lot of kinds of engineering to be very good at being a demon because you need to make sure the things you're building work, what d'you want to start with -"

"Math, I guess? I think you need to know math for that, and all people will teach me is multiplication."

"Do you know how to graph stuff? Calculus is really easy to explain from that."

"Yeah. Had to learn on my own, though." She sounds proud of that.

"Good for you!" Here's a holoscreen with a graph. "So imagine that we put a tracker on some guy and its GPS - do you even have GPS - okay, anyway, our tracker can't tell us how far he's gone but it can tell us how fast he's going, here's the graph of how fast he's going. We want to figure out how far he's gone. D'you see how -"

"You have to multiply the speed by the time?" she guesses. "But it changes all the time..."

"Yes, it does. So let's make some simplifying assumptions - pretend he's only got so much acceleration, his speed increases linearly until he's going this fast and then it flattens out -"

"So after here you can just multiply this together with how long he's at this speed, but before—" She squints. "If you could divide the triangle in little pieces you could do the same, sorta?"