“Hey, careful!” Pav said.

The tunnel was a smooth rocky cylinder with one flat side, the floor. No piles of rock or uneven patches. Even so, it was hard to keep track of your feet when you couldn’t see them, so she slowed down.

They heard another bark when they were within a hundred meters of the opening. “I wish he would find us,” Pav said. “Isn’t that what dogs are supposed to do?”

“Maybe he’s found something more interesting.”

As they reached their landing spot, they saw Cowboy…and the more interesting object: an Asian man in a white shirt still brushing dirt off his slacks.

“It’s Zhao,” Pav said, stopping short.

“I don’t—”

“The guy who shot that other guy?”

Rachel was suddenly more afraid than she’d been when falling down the shaft. “What do we do?”

It was too late to run. Zhao had seen them. He waved and said, “Well, mission half-accomplished. I’m Zhao.”

Rachel realized there was no point in running away. “I’m Rachel; this is Pav. What was your mission?”

“Find you two and bring you back.” He looked up at the opening, then back at them. “Didn’t you hear me calling?”

“No,” Rachel said. At the same time, Pav said, “We were down the tunnel.”

“Chasing the dog,” Rachel finished.

“So where is he?”

“He was just here a moment ago,” Rachel said. “Barking at you.”

“Never saw him, never heard him.”

“Well, the acoustics—” Pav said, stopping when Zhao dropped to his knees and began brushing the ground.

“Looking for something?”

He stood up with a water bottle. “This.” He offered it.

Rachel drank, reminding herself to take only a couple of sips. There were three of them on a bottle, and who knew how long it would have to last. “Thank you.”

Pav wiped his mouth, then said, “Uh, how did you get down here?”

Zhao shook his head. “I seem to have fallen.”

“Us, too,” Rachel said.

“Chasing the dog?” Zhao stepped back to look up the shaft. “I was actually quite careful. I’m not sure I wasn’t pushed.”

Rachel looked at Pav. Even in the low light, she could see his eyes widen, as if to say, Weirdo! “Well,” he said, “I don’t think the dog is the only animal on the loose up there….”

“I would have smelled or heard a dog,” Zhao said. “This was a person.”

He stepped from side to side, trying to get a better look up where they’d come from. “Hey, up there!” Without much success, he tried to pull himself up on the rocky wall. “We’re down here!”

“What are you doing?” Rachel said.

“He’s still up there,” Zhao said.

She and Pav both looked toward the top of the shaft. Zhao was right; somebody’s head popped into view, then out again.

“What the hell?” Pav was getting angry. “Help us out!” he shouted. “Throw a rope or something!”

Nothing. “Can you hear us?” Pav shouted.

Still no response, but the figure appeared for another instant.

“Who is that?” Pav said.

“I think it’s Camilla,” Rachel said.

“The Portuguese girl?” Zhao said. “If she was the one who pushed me, I’m going to fire my martial arts trainer.”

“Camilla!” Rachel called. “Get my father!”

“Can she hear us?” Pav said.

“She’s ten meters away!” Zhao said.

Then the opening—not large to begin with—got smaller.

“What the hell?” Pav said. “Is she putting stuff in the opening?”

“Hey, Camilla!” Rachel shouted. Zhao, too. And Pav.

Their pleas had no effect. The opening above them suddenly closed, leaving them in darkness.

Rachel wasn’t sure, but it seemed that the strange little Portuguese girl had walled them in.

MAKALI

Feeling as if she could run forever, Makali Pillay led the charge up the ramp out of Vesuvius Vent. In a ragged line, with Zack closing in on her, Williams—surprisingly—in third, followed by Dale and Valya, they emerged into the harsh bright sunlight of a Keanu day and quickly headed upward to the surface.

She had only studied the imagery of the original exploration by the Brahma and Destiny crews…the snowy, shadowed crater with the obviously artificial ramp spiraling up one side. But she remembered the ramp as relatively clean, bare rock. Now it was covered with debris…easily avoided or jumped over, but obviously new.

And great swatches of snow were gone, especially in the higher reaches. “It looks so different!” she said.

“Setting off a nuke will do that,” Zack said.

Makali and now Zack were taking giant leaps as they gained altitude. “Careful,” Zack said. “It’s easy to overshoot in microgravity.”

Makali acknowledged the warning without really altering her actions. She judged the vent to be at least thirty meters deep, a hole big enough to swallow a ten-story building. She also realized that as they got farther from the junction and the tunnels, gravity seemed to diminish sharply. She lost traction once or twice but was saved from a spill by Zack. “What did I tell you?” he said.

In the exuberance of exploration, and low gravity, Makali found it hard to slow down. Even Williams was springing up the ramp not far behind.

“Let’s be smart about this,” Zack said, trying to get Williams’s attention. “There’s no guardrail!”

Makali thought his worries were unfounded. To her it was obvious that a fall from the ramp would be slow and painless…assuming you even hit the base of the vent at all. She knew that most asteroids and other astronomical bodies were so small, so lacking in mass, so bereft of gravity that a human runner could easily reach escape velocity.

Thinking about that made her worry more about becoming a human satellite of Keanu than about a serious fall.

Reaching the top, she and Zack stopped as quickly as the slick surface and low gravity would allow.

Williams was not so ept. He lost his footing and landed on his backside, sliding up to and into Zack and Makali. Makali was afraid they would topple like bowling pins, but Williams only bounced and spun.

By the time she and Zack had helped the writer to his feet, Dale and Valya had reached the top of the ramp, too.

“Hey, Makali,” Dale said, as soon as he was within touching distance. “Now that we’re here, mind telling us why you took off?”

God, he was an irritating human being. Had she been his commander on a long-duration mission, she wouldn’t have just sent him home early…she would have ejected him from the airlock. “Because we were about to turn back and go into the tunnels,” she said. “This would be my only chance to walk onto the surface of Keanu.”

“Well, is it worth it?”

“Look for yourself.” Her first impression was that she had entered a world possessing only two colors: black and white. Even the advanced adaptive optics of her skinsuit struggled as she looked from surface to sky.

Makali had seen as much imagery of Keanu’s surface as anyone. It looked like any other large, icy comet or asteroid…rocks interspersed with ancient ice and snow, visually a lot like Iceland in the winter.

No longer. While the distant hills looked much the same, here most of the snow was gone…and in its place lay a shiny, smooth surface. “What the hell is this?” Zack said.

“I take it it looked different a week ago.”

“Correct.” He walked onto the shiny material, toeing it. “These are actually big plates,” he said.

As her eyes adjusted, Makali had seen edges, too. “Do you suppose this is the real outer skin of the Architect’s starship?” Williams said.

“It’s not uniform,” Dale Scott said. He had walked off a dozen meters. “The plates end here.”

Makali surveyed the area at the top of the vent. “Yeah, it looks as though there’s plating all around the rim.”

“It’s as if Vesuvius were built, not found,” Valya Makarova said.

“Well, they used it and the other vents like giant rockets,” Dale said.

Wade Williams wasn’t wandering around the shiny white plates. He pointed to the sky. “Raise your eyes, friends.”