"Plants as different as moss and trees can definitely evolve from a common ancestor! But if you're curious about fairyland in particular, we could go there a hundred million years in the past and see for ourselves."

"Are you sure that's long enough?"

"If species are changing at all, that should be long enough to notice. But there's no reason we couldn't go farther. If your universe has a beginning, we can't go before it, but that's just about the only limit." Well, she did have to take the Bus to a mechanic after she went to a few picoseconds after the Big Bang, but they had both felt the destabilized zoroflooper was worth it for the excellent pictures.

"I'm not sure if it had a beginning or not!"

"Well then, what do you say we aim for a billion years back and see if the Bus can find it?"

"Sure, why not."

"Alright then--to the Bus!" Ms Frizzle jetpacks out of the flower and over to the Bus, who has grown metal flowers all over herself in what may be history's most flamboyant attempt to blend in. The Bus zaps her back to full size on the way.

"...I like the flower sculptures," Promise comments to the bus.

The Bus smiles appreciatively, and zaps Promise back to full size as well.

She boards.

And off they go to Fairyland's extremely distant past! The trip takes noticeably longer, this time, and the glowing colors outside the windows smear into streaks like mixing paint. Eventually they come to a stop again.

It's not very interesting, Actually, it's totally dark.

She flicks on the Bus's headlights. "How does fairyland handle lighting, incidentally? Infinite flat planes have a number of interesting solutions there."

"There are suns in various places. Even night places aren't this dark though."

The headlights illuminate a very empty flat land.

"Do the suns move at all? Do you know how large they are, and whether they run on nuclear fusion? And if you don't know what nuclear fusion is then I'm curious how your language handling rendered it." Promise's language handling thing is very intriguing in general--she can only barely sense it and it seems to be very different from what the Bus would otherwise be doing. She sets up a scan of the conditions outside: breathable air, by her definition and Promise's somewhat stricter one? Radiation levels unexceptional? Temperature recommending a sweater or a spacesuit?

"They move. I don't know if they are the sort of thing that has a size. I don't speak a language and don't know what nuclear fusion is."

There is in fact not air. It's also not radioactive at all. A spacesuit would be the correct attire for the season.

"What sort of thing could the suns be that doesn't have a size?" she asks, popping open a wall compartment and pulling out two spacesuits. One of the spacesuits has a wing-sized amount of extra room in the back. "Also, you'll want to put this on if you're coming outside."

"They're the warm lights in the sky, and they don't look bigger if you fly higher. And most of them aren't around all the time. What is that?"

"This is a spacesuit! It provides you with breathable air, which outside is presently lacking. It goes on like this." She unzips hers and climbs into it, her skirt having turned into pants some time while Promise wasn't looking.

"Oh, if it's the wrong sort of air for breathing I can breathe through my wings."

"It's actually no air at all, does that bother you?"

"...yes, I don't think that would be comfortable. The suit deals with that?"

"Yes! Air comes out of this hose here, and when you exhale it gets drawn away by this other hose."

"That part I don't think I need but it won't do me any harm." In she goes.

The Bus has helpfully acquired an airlock, so as soon as Promise is suited up they can head on out!