Disclaimer: The Magic School Bus, along with several lines of dialogue therefrom that get quoted in this story, belongs to Scholastic Studios, Inc. The image above is NASA's.

"Janet's right! Ms. Frizzle could be on Saturn – couldn't she?"

"Okay, Arnold, but it's your job to keep your crazy cousin under control!"

Wanda spun the controls, and the bus lurched toward Saturn. I sighed, unbuckled my seatbelt, and wandered toward the nearest porthole.

"Something wrong, Phoebe?" said D.A., glancing up from her computer console.

I shrugged. "I don't know. It's just… when I came to school today, I didn't expect to be a billion kilometers away from home before lunch."

D.A. smiled. "Not something that would have happened at your old school, huh?"

I shook my head and stared out the porthole. Eight or nine of Saturn's moons were just barely visible, whizzing around the Ringed Planet just like the Solar System on the model Ms. Frizzle had put on the blackboard that morning. I wasn't sure why they were moving so fast, but I guess time gets weird when you're trying to see the entire Solar System in one afternoon.

I squinted out the window, trying to pick out the moons I knew. I recognized Titan and Enceladus, but none of the others meant anything to me. Carlos and D.A. had been the ones who were assigned to cover Saturn, not me.

There was one moon, though, that I kind of liked. It was the farthest out from Saturn, and only about 200 kilometers across – not even big enough to be round. Next to the huge globes like Titan, it looked tiny, pitiful, and out of place – in other words, pretty much the way I felt every time I walked into Ms. Frizzle's classroom.

There was another odd thing about it, too, that took me a few moments to notice. All the other moons were moving clockwise relative to the bus, but my little squished moon was orbiting counter-clockwise. When I realized that, the last bit of my heart went out to it.

"D.A.?" I said.

"Hmm?"

I pointed out the window. "What's that moon called?"

D.A. frowned, and took a book out of her bag. "Let's see," she said, flipping through the pages. "According to my research, that would be…" She paused, glanced up, and grinned at me. "…Phoebe."

I blinked. "Phoebe?"

D.A. nodded, and looked back down at her book. "'The outermost known satellite of Saturn is called Phoebe,'" she read. "'It is much smaller than Saturn's other major satellites, and has a highly eccentric and retrograde orbit. This has caused some astronomers to speculate that it is not a natural satellite of Saturn at all, but a Sun-orbiting asteroid that came too close to Saturn at some point and was captured by its gravitational field.'"

I think I might have actually squealed at that point. Fortunately, it was drowned out by Ms. Frizzle's voice coming over the intercom. "Ms. Frizzle to bus, Ms. Frizzle to bus, over."

Hastily, I scurried back to the nearest seat and strapped myself back in just as Ms. Frizzle finished: "…all the stars we can see out here! Oh, it's so beautiful!"

"Come back!" shouted Ralphie, who was sitting across from me now. "What about a hint?"

"She just gave us a hint, Ralphie!" said Wanda.

"She did?"

"Yeah! She can see the stars! Which means she can't be on Saturn; she could never see the stars through all those storms and clouds!" Wanda fired up the bus's rocket thrusters, and we were off to the next planet.

"You know, Ralphie," I said as Saturn dwindled off into the distance, "I know you're worried about Ms. Frizzle, but you really shouldn't be yelling at your teacher." I grinned. "In my old orbit, you could have gotten a detention for that."

Ralphie turned and stared at me. "Your old what?"

I sighed. "Never mind."