Seeing the activity, Rachel said to Pav, “We can’t let Zeds out.”

“He knows.”

“Does he need anything—?”

Pav was smiling. “You forget who you’re dealing with, lady. I assigned Yahvi to get water and whatever else he needs for the moment. Right now he’s operating on his suit, and we got it tanked up before we left Yelahanka.”

“Poor thing. It’s like he’s a prisoner.”

“Are we that much better off?”

Rachel laughed. They weren’t. Edgely had asked them to remain within one hangar in Darwin’s cargo terminal. “There are bathrooms,” he said, “and a bit of a buffet upstairs.”

Sanitary facilities and food—that was what Rachel’s life was reduced to. It reminded her of the things her father had told her about the realities of spaceflight. “Boredom and repetitious tasks,” he said. “And an hour of exercise every day, whether you think you need it or not. What you wind up thinking about is what’s next on your meal schedule, and how long is it going to take you to operate the zero-g toilet.”

Well, in a way, this trip to Earth was a form of space exploration.

“Speaking of which,” Rachel said. She didn’t need a bathroom as much as she needed a moment of privacy.

“Go,” Pav said.

“What about you?”

He tapped the side of his head. “Going to try to raise Keanu. They need to know about Sanjay.”

“From here?” One of the reasons Rachel had resisted leaving Adventure was the likely loss of communications with Keanu. Not that they’d been great or even good.

“You never know. It’s worth a try.”

She emerged from the bathroom to find Edgar Chang and Tea waiting for her. “Edgely has something important to show us.”

The high-school-teacher-slash-astronomer had commandeered an office on the second floor of the hangar building. From the pictures on the walls—cargo aircraft going back to the last century—and models of same on the desk, the place belonged to a veteran pilot. Edgely gently removed the models to clear the desk for his datapad.

Pav, Tea, and Xavier joined them. “Where’s Yahvi?” Rachel said.

“Ferrying some interesting food-type thing to Zeds,” Tea said.

“Here we go then.” Edgely had an image on the notepad. “You will recall,” he said, sounding and acting every centimeter the secondary school lecturer, “Mr. Chang told you that there were satellites that the Aggregates mistakenly thought to be dead.

“Actually, there were quite a few of them. When your Reivers began showing themselves twenty years back, some operators turned their birds off—or, rather, pretended to. So the human race does have a few overhead assets, if you know whom to ask.

“The trick is, no one has built or launched any new ones in almost twenty years. Maneuvering fuel runs out and solar panels degrade. Satellites don’t last forever. And the low-altitude birds, which are the most useful for taking pictures, are subject to atmospheric drag.”

“How do you know all this?” Rachel said. Her suspicions, never totally put to rest, were now up and demanding attention.

“Oh, Kettering tracks them,” Edgely said. “That’s really how the group started . . . English schoolboys were tracking secret Soviet rocket launches back in the 1960s. Some of them grew up and kept up with their hobby.

“The teacher I mentioned, Mr. Hall? He was a junior member, and he later emigrated to Australia and became a teacher in Alice Springs, which is where I grew up.” He laughed a little too loudly. “It was so perfectly appropriate!”

“Why?” Pav said.

“Alice Springs was home to a big American satellite downlink station. Just outside town there was a big base, all fenced off, with these giant golf-ball-shaped domes. I mean, even if you had no interest in space and astronomy, you would still be curious!

“I think, in fact, that Mr. Hall had originally come to Alice Springs to work at the facility—lost his job, I guess, and wound up teaching me and a few others at Centralian about satellites and telescopes and . . .” He suddenly stopped. “This is boring and off the subject.”

“A little,” Rachel said. But she had enjoyed hearing it, because it went a long way to making her feel better about trusting Edgely.

“Er, let’s just say I wouldn’t have found Keanu without Mr. Hall’s help. And I sure wouldn’t have been able to get hold of this recon imagery.”

He showed his datapad, which displayed a satellite image of a desert landscape.

“Where is this?” Pav said.

“And more to the point,” Rachel said. “What?”

“You’re looking at southern Utah and northern Arizona, Free Nation U.S. That facility is what the Aggregates and their human allies call Site A, though most everyone calls it the Ring.”

It was easy to see why: A giant ring-shaped structure was obvious in the image, a blot on the desert landscape. It had been carved through several mountains and one plateau, too.

“How big is that thing?” Xavier said.

“The Ring itself is over ten kilometers in diameter,” Edgely said.

“It appears to be some kind of high-speed particle accelerator,” Chang said.

“A bit like the Large Hadron Collider?” Edgely offered.

“Larger—”

“And probably nastier,” Tea said. “I’ve actually been to the LHC, and one big difference is that the real one’s underground. So why is this aboveground?”

“I wasn’t suggesting that it actually was a particle accelerator,” Edgely said, a bit defensively. “The Aggregates or whatever you call them seem to know a lot more about physics than we do.”

Chang tapped on a strange-looking structure in the middle of the Ring. “Is that a communications dish or telescope?”

Rachel peered closely at the fuzzy image. “If it were a dish, wouldn’t it be inside a dome?” she said, remembering her father’s work after Megan’s death, how they had visited tracking sites and telescopes.

“They’ve also got some pretty standard buildings to go with this,” Pav said. He indicated a collection of rooftops at the center of a couple of roads and rail lines. It was off to one side of the Ring structure. “And a weird-looking mound—”

“Aggregate habitation,” Edgely said.

Pav grunted with disgust. “And serious power lines, coming from the south and the west.”

“Las Vegas and Phoenix,” Edgely said. “We knew there were nuke plants in both places, before the Aggregates. No reason to think they’ve shut them down since.”

“And what is all that?” Rachel said. She indicated what appeared to be fields of rectangular lumps arrayed to the north and east of the Ring, on flat ground.

“Let me,” Chang said. He zoomed the picture in. The lumps resolved into vehicles that looked as though they were armored, with rounded turrets and protruding cannon barrels. Some displayed coils, others screens. All of them looked intimidating.

“Any idea what those are?” Rachel said.

“Those look like tanks,” Pav said, surprising his wife. “Armored personnel carriers.”

“That’s what my people think, too,” Chang said.

“Why the hell,” Tea said, speaking for Rachel and everyone in the office, “would the Aggregates be assembling this . . . invasion force out in the middle of nowhere?”

“Clearly it is associated with the Ring,” Chang said.

“Obviously,” Tea snapped. Rachel could see that the former astronaut was in her element, dealing with technology and military matters with men who were slow to accept her expertise. Go, girl. “I mean, I look at this Ring and think particle beam weapon, some kind of big fricking ray gun.”

The fine hairs on Rachel’s back tingled. What would be the likely target for a giant Reiver ray gun? It had to be Keanu. The thought was so terrifying and appalling that she couldn’t say it out loud.

“But what’s not obvious is how that Ring becomes some kind of force multiplier.”

No one could offer an explanation.