Vadesh—who could hear everything they were saying, Rigg never allowed himself to forget that—was standing on the ground near the end of the tunnel. “Come along, the door only opens for a few moments and I’d hate to have either of you get caught in it when it slides shut.”

As they got off the wagon, it immediately whisked away back down the tunnel.

“No return trip?” asked Loaf.

“I can always call it back,” said Vadesh. “And there are many other ways to make the same journey.” Vadesh turned to face the wall. He said nothing, made no gesture—but he did face the wall. Why, Rigg wondered. Was he communicating some other way?

Apparently so, because the end of the tunnel was suddenly gone. What had seemed to be smooth stone was now a continuation of the tunnel. The wagon could have kept going. Only now, beyond where the tunnel had ended, there was an obvious station, with loading dock, stairway, and other doors, not disguised at all.

Here, though, the stairway went farther down rather than returning toward the surface. They had come down to get to the tunnel at the other end, and had traveled steadily downward since then, if Rigg’s directional sense was at all reliable in a place like this and at such a speed. And yet their destination was lower still.

But they did not take the stairs. “Down,” said Vadesh, and a set of doors opened to reveal a smallish room. Vadesh walked in. Loaf and Rigg followed, and then the doors closed. Rigg could not understand why they would enter such a room, which had no doorway other than the one they had come through.

“It’s an elevator,” said Loaf. “It’s on pulleys. The whole room goes up and down, with counterweights to balance us. Some of the taller buildings in O have them, and a bank in Aressa Sessamo had one, too.”

“Very good,” said Vadesh. “Only there’s no counterweight.”

They plummeted.

“Exhilarating, isn’t it?” asked Vadesh.

Rigg and Loaf were both clutching at the wall, filled with panic.

“Oh, sorry,” said Vadesh. “I forget how sensitive humans can be.”

Suddenly the sensation of falling went away. “Now we have a mild inertial field. You have to understand that humans knew about this sort of thing when we first built the colony. They used to enjoy riding the elevator down without the field. They enjoyed the thrill.”

“Then they weren’t human,” said Loaf.

“Oh, people get used to so many things,” said Vadesh, “if they only give themselves the chance.”

The doors opened. There was a bridge in front of them, spanning a gap of about six meters. On the other side was a smooth, convex surface of fieldsteel, exactly like the surface of the Tower of O.

As they stepped onto the bridge, Rigg looked to left and right, up and down. “It’s the Tower of O, lying on its side,” he said.

“Let’s say that the Tower of O, as you describe it, was probably intended to be a monument to a starship. Not the real thing. Come along. Ship, open!” said Vadesh.

A gap appeared in the side of the ship, right where the bridge ended.

“Welcome to the starship that brought humanity to Garden,” said Vadesh.

“One of nineteen,” said Rigg.

“It began as a single ship,” said Vadesh. “We had an accident. The physics of it is beyond you, I promise you.”

“You never know how much Father taught me,” said Rigg.

“I know he didn’t teach you that, because even the ship’s computers don’t understand it. Nineteen computers brought one ship into the folds of space, but brought it out again in nineteen slightly different locations. Oops.”

“And where on this starship are you taking us?” asked Rigg.

“To the control room. To the place where all the decisions were made. Where Ram Odin plunged the human race toward its first successful colony on an earthlike planet.”

As they walked along narrow passages, Rigg got the distinct impression that something was helping them move—that each step took them farther than it should, that their bodies were somehow lighter here. Another field? Probably.

A door opened and they stepped into a spotlessly clean room, walls and floor and ceiling all the same light-brown color. Along one wall there was what seemed to be a track, rather like the passage that the wagon had run along, only much narrower. There were doors at both ends.

In the middle of the room was a table, about as long as Vadesh was tall. Dangling from the ceiling were three lights, surrounded by what looked like arms or tentacles. Vadesh raised his hand and the lights all moved toward it. Also, a seat emerged from under the table and slid into position in front of the table.

“This is where the ship was controlled?” asked Rigg.

“You see the track there—I know you noticed it, Rigg, you’re such a clever boy. There are really three control centers—one for navigation through space, one for controlling all the systems internal to the ship, and one for field generation. Whichever one the pilot needs is brought in along that track and placed on the table here. Very quick and completely automatic. The pilot sits here and the controls come to him.”

Lies, Rigg was sure of it. The system seemed unwieldy. Why would controls be hidden away? It made no engineering sense.

The table was about the size of a human body—just long enough, just wide enough. Rigg looked up at the arms surrounding the lights. Vadesh was controlling the movements of those arms right now. What was on the ends of the arms? Tools of some kind. Hard to guess their purpose.

“Have a seat,” said Vadesh to Loaf.

“Don’t,” said Rigg.

“Now, Rigg,” said Vadesh. “I thought you said you weren’t in charge of the expedition anymore.”

“It’s not what he’s telling us,” said Rigg.

“How would you know?” asked Loaf. “You’ve never seen a starship. How do you know anything?”

“It makes no sense,” said Rigg.

“Nothing has made any sense since I met you,” said Loaf. “But if this is the way to take down the Wall and get home, then I’m going to sit down.” Loaf sat.

At once the chair moved—but only a little, to take Loaf’s height and weight into account. Then it held still.

“You see?” said Vadesh. “It adjusts to the pilot. Which it thinks you are, since you have a jewel for this starship.”

Rigg wanted to ask Loaf for the jewels, but he didn’t want to test Loaf’s friendship. Nor did he want to find out just how determined Vadesh was to keep them out of Rigg’s possession.

“Shall we bring in the controls for the field generators?” asked Vadesh.

“If that’s what will let me bring down the Walls and get home,” said Loaf.

“You have to hold up the jewels—just hold them up, palm open—and command the starship to bring in the controls.”

“What do I say?” asked Loaf.

“Try, ‘Bring in the field controls, ship,’” answered Vadesh.

At that moment Rigg made a connection. Vadesh was telling Loaf to speak to the ship and give it an order. Father had taught Rigg a special command language. He had said it was a way to rule the stars. It wasn’t a real language at all, of course. Just a series of numbers and letters, which Rigg had had to memorize and repeat every few days, then weeks, then years. Father wouldn’t tell him how they might rule the stars, and no matter how many times Rigg repeated the sequences that Father called “words” in this command language, the stars never did anything. Rigg had called him on this once, and Father had looked at him as if he were a child—which he was—and said, pityingly, “It doesn’t work here,” as if Rigg should have known that.

Now Rigg was inside a starship. And an expendable just like Father was telling a human to issue commands.

Loaf had already spoken the command while Rigg was thinking back and making the connection. One of the doors opened and a low cart slid in along the track, then transferred automatically to the table in front of where Loaf was sitting.