Eventually, I fell asleep on Samm's shoulder. I slept for four hours, and he held me close the whole time.

When I awoke, we were gliding down the long dark valley into Wonderland Jumble.

Wonderland Jumble is an irregular band of astonishing terrain that stretches and sprawls like a salamander curled around the Lunar South Pole. It's as uneven as a lava flow, only worse. The craters are so overlapped, they're impossible to define; the ground is torn, and the rocks are broken. Slabs of material are turned every which way, creating impossible deep chasms. Steep avalanches of rock teeter precariously everywhere; the angle of repose is different on Luna, so rockslides are steeper. Where the crust has crumpled it tilts in directions impossible on Earth. The whole thing is a colossal badlands so black and ugly even Loonies shudder over it.

It's impractical to set any pylons here for the train. According to the video guide, they couldn't get the teams in, there was no place for them to stand, and there was no way to reliably anchor anything. The deep-level radar showed little access to bedrock. Even the intelligence engines couldn't find a cost-effective resolution to the problem. Nevertheless, six major train lines converged at the south pole, and a hub was needed.

The solution was to build a floating foundation. They began by lowering a large platform with a bed of inflatables on its underside onto the least unpleasant site. Once the platform was in place, they brought in tanks and pumps and spent over a year laying down three square kilometers of industrial construction foam. They pumped it into every crevasse and chasm, layering it up higher and higher, until they'd built an enormous ziggurat of artificial bedrock, the only flat piece of ground for a hundred klicks in any direction. Spaced here and there throughout the hardening pyramid were tunnels, storage tanks, bunkers, process tubes, vents, and access channels—and also the anchors for the Wonderland Pylon, the tallest structure on Luna.

Instead of a chain of pylons crossing the Jumble, there's only a single installation, nearly two kilometers high. It's a spindly, stick-figure structure; from a distance, it's all lit up, and like all the other pylons, it looks like the outline of a pyramid—only this one is much taller, as if it's been stretched out vertically, and just like everything else on Luna, it looks like it needs to be a lot sturdier too. And because everything about it is so thin and wiry, it doesn't feel as big as it really is.

But it takes so long to get there, and it just keeps getting taller and taller on the horizon, that you start to realize (again!) that there's no sense of scale on Luna. Everything lies about its size and its distance—it's either too close or too far, too big or too small. Meanwhile, the train keeps rising up and up toward the apex of the pyramid, higher and higher, like an airplane climbing to altitude, until you get another chill climbing up your spine and another wunderstormof awe.

There's an observation deck at the front of the train on the top deck; the passengers can look forward and up. The pilot's compartment is directly beneath, so she can see forward anddown—which she needs to do for docking at places like Prospector's Station.

Long before the train approaches the top, you can see the lights of Wonderland, a vertical cluster of cargo pods, tubes, and inflatables hanging from the apex of the tower. All the different lines meet at Wonderland Station, so passengers can transfer from one train to another and trains can be serviced. It looks like an industrial Christmas tree. There are cranes and wires and tubes sticking out everywhere, all kinds of ornaments, and lights of all sizes and colors, rotating, flashing, shining, and blinking. It might be pretty if it weren't so ugly. A thousand kilometers from anywhere, in the middle of the most intolerable landscape on two worlds, the whole thing looks like an oil refinery in the dark.

There's a large ground station at the base of Wonderland Tower, with tanks and domes and racks scattered all over the flat surface of the artificial bedrock. It's a bright jumble of cargo pods and oversized equipment, but most folks don't go down to it, because it's mostly industrial facilities and not a tourist site. Wonderland Station looks like one of those places you want to leave as quickly as possible—like an airline terminal where you have to change flights.

As we rose up closer, we could make out all the different lines, each one coming in from a different angle. The docking pods were all at different heights, so there was no danger of trains colliding. Our train slowed to a careful crawl for the final approach to the station, finally stopping at a pod near the top. As soon as the bell chimed, everyone stood up and gathered their belongings, then headed downstairs to the exit ladder. The blue-haired lady bid us a polite farewell. Her tarantula made as if to pat me on the knee again, then thought better of it; she stopped herself in mid-gesture. She turned it into a clumsy wave instead.

"You be careful on the ladders, dear. You'd think with all their marvels, they'd have proper stairs." She turned to her husband. "I mean, really. If they can build a city on the moon, why they can't build stairs?" Yes, definitely tourists.

There weren't any stairs anywhereon Luna. There was no need for them. And they'd be inefficient anyway, they'd mostly causeaccidents. You can't walk up stairs in low gravity, we discovered that at Geostationary. The risers feel too small. You want to bounce up them—but if you try three or six or nine steps at a time, you just trip ass over elbow, because the horizontal component of your trajectory doesn't match the vertical. You end up flying, as you collide with the next three steps. The Loonies learned real fast that stairs are too dangerous.

In one-sixth gee, everybody uses ladders. Even old people. There's no such thing as old and feebleon Luna. There's only old. In Lunar gravity, it's almost impossible to be weak. If you're too weak to get up a ladder on Luna, you're already dead.

It doesn't take long to realize that low gee changes everything.It's not the big differences as much as it's the little ones. You're constantly bumping up against what you don't know. You're reminded of it every time you go to the bathroom. It's there when you pour a drink of water, when you sneeze, when you bounce into bed, and when you get up again. You feel it when you sit, you feel it when you stand. It takes time to develop Lunar reflexes—and until you do, you move like a dirt-sider. A terrie. You bounce off a lot of walls.

Fortunately, Janos had his space legs. Of course. Samm walked slowly, because he was carrying sleeping Pattykin. And I was pregnant, so I was going to look awkward no matter what the gravity.

We didn't wait for Alexei; we assumed he'd catch up with us. Where could we go without him? We lowered ourselves down the ladder into the terminal and headed straight for the lounge, hoping to find some dinner and a quiet place to talk.

There was a post just outside the restaurant, with arrows attached to it, pointing out how far away we were from everything. The bright-liner catapult was 1575 kilometers north of here, stretched horizontally across the Lunar equator. There was also an interactive panel that would let you query the time and distance to anywhere else in the solar system. I wanted to ask it how far we were from El Paso, but Samm and Janos dragged me on. The sweet smells from the café were too enticing.

The food at The Mad Tea Party was much better than the packaged snacks on the train. We had fresh bread and butter, sliced fruit salad, cheese, and lemonade. All grown on Luna. We ate in silence for a while; I guess none of us wanted to be the first to bring the subject up.