“Are we close enough yet?” Sax asked.

“Almost.”

Sax looked down again at the thickening crescent of the morning. There on the dark rough highlands of Hesperia, a cloud of smoke was billowing up from the dark surface just beyond the terminator, into the morning light. Even at their height they were in that cloud still, in the part that was no longer visible. The lens itself was surfing on that invisible thermal, using its lift and the pressure of sunlight to hold its position over the burn zone.

Now the entire lens was in the sunlight, looking like an enormous silver parachute with nothing underneath it. Its silver was also violet, sky-colored. The cup was a section of a sphere, a thousand kilometers across, its center some fifty kilometers above its rim. Spinning like a Frisbee. There was a hole at the peak, where the sunlight poured straight through. Everywhere else the circular mirror strips that made up the cup were reflecting the light from the sun and the soletta, inward and down onto a moving point on the surface below, bringing to bear so much light that it was igniting basalt. The lens mirrors heated up to almost 900°K, and the liquefied rock down there was reaching 5,000°K. Degassing vola-tiles.

Into Sax’s mind, as he considered the great object flying over them, came the image of a magnifying glass, held over dry weeds and an aspen branch. Smoke, flame, fire. The concentrated rays of the sun. Photon assault. “Aren’t we close enough yet? It looks like it’s right over us.”

“No, we’re well out from under the edge. It wouldn’t do to get under that thing, although I suppose the focus wouldn’t be right to fry us. Anyway it’s moving over the burn zone at almost a thousand kilometers an hour.”

“Like jets when I was young.”

“Uh.” Green lights blinked on one of his consoles. “Okay, here we go.”

He pulled back on the stick and the plane stood on its tail, rising straight at the lens, which was still another hundred kilometers higher than they were, and well to the west of them. Peter pushed a button on the console. The whole plane jerked as a bank of fletched missiles appeared from under the plane’s stubby wings, lofting with them and then igniting like magnesium flares and shooting up and away, toward the lens. Pinpricks of yellow fire against that huge silvery UFO, eventually disappearing from sight. Sax waited, lips pursed, and tried to stop his blinking.

The front edge of the lens began to unravel. It was a flimsy thing, nothing but a great spinning cup of solar sail bands, and it came apart with startling rapidity, its front edge rolling under it until it was tumbling forward and down, trailing long looping streamers which looked like the tangled tails of several broken kites, all falling together. A billion and a half kilograms of solar sail material, in fact, all unraveling as it fluttered down in its long trajectory, looking slow because it was so big, though probably the great mass of material was still moving at well above terminal velocity. A good portion of it would burn up before it hit the surface. Silica rain.

Peter turned and followed it in its descent, keeping well to the east of it. And so they could still see it below them, there in the violet morning sky, as the main mass of it heated to an incandescent glare and caught fire, like a great yellow comet with a hairy tangled silver tail, dropping down to the tawny planet. All fall down.

“Good shot,” Sax said.

Back in Wallace Crater they were welcomed as heroes. Peter deflected all congratulations: “It was Sax’s idea, the flight itself was no big deal, just another reconnaissance except for the firing, I don’t know why we didn’t think of it before.”

“They’ll just drop another one into position,” Ann said from the edge of the crowd, staring at Sax with a very curious expression.

“But they’re so vulnerable,” Peter said.

“Surface-to-space missiles,” Sax said, feeling nervous. “Can you invent — can you inventory all orbiting objects?”

“We already have,” Peter said. “Some of them we don’t have ID’d, but most are obvious.”

“I’d like to see the list.”

“I’d like to talk to you,” Ann told him darkly.

And the rest quickly left the room, wagging their eyebrows at each other like a bunch of Art Randolphs.

Sax sat down in a bamboo chair. It was a little room, without a window. It could have been one of the barrel vaults in Underbill, back in the beginning. The shape was right. The textures. Brick was such a stable staple. Ann pulled a chair over and sat across from him, leaning forward to stare in his face. She looked older. The vaunted Red leader, vaunted, gaunted, haunted. He smiled. “Are you about due for a gerontological treatment?” his mouth said, surprising them both.

Ann brushed the question off as an impertinence. “Why did you want to bring down the lens?” she said, her gaze boring into him.

“I didn’t like it.”

“I know that,” she said. “But why?”

“It wasn’t necessary. Things are warming up fast enough. There’s no reason to go faster. We don’t even need much more heat. And it was releasing very large amounts of carbon dioxide. That will be hard to scrub. And it was very nicely stuck — it’s hard to get CO₂ out of carbonates. As long as one doesn’t melt the rock, it stays.” He shook his head. “It was stupid. They were just doing it because they could. Canals. I don’t believe in canals.”

“So it just wasn’t the right kind of terraforming for you.”

“That’s right.” He met her stare calmly. “I believe in the terra-forming outlined in Dorsa Brevia. You signed off too. As I recall.”

She shook her head.

“No? But the Reds signed?”

She nodded.

“Well… it makes sense to me. I said this to you before. Human-viable to a certain elevation. Above that, air too thin and cold. Go slow. Ecopoesis. I don’t like any of the big new heavy-industry methods. Maybe some nitrogen from Titan. But not any of the rest.”

“What about the oceans?”

“I don’t know. See what happens without pumping?”

“What about the soletta?”

“I don’t know. The extra insolation means less warming needed from industrial gassing. Or other methods. But — we could have done without it. I thought the dawn mirrors were enough.”

“But it’s not in your hands anymore.”

“No.”.

They sat in silence for a while. Ann appeared to be thinking. Sax watched her weathered face, wondering when she had last had the treatment. Ursula recommended repeating it every forty years, at a minimum.

“I was wrong,” his mouth said. As she stared at him, he tried to follow the thought. It was a matter of shapes, geometries, mathematical elegance. Cascading recombinant chaos. Beauty is the creation of a strange attractor. “We should have waited before we started. A few decades of study of the primal state. It would have told us how to proceed. I didn’t think things would change so fast. My original idea was something more like ecopoesis.”

She pursed her lips. “But now it’s too late.”

“Yes. I’m sorry.” He turned a palm up, inspected it. All the lines there were the same as always. “You ought to get the treatment.”

“I’m not taking the treatment anymore.”

“Oh, Ann. Don’t say that. Does Peter know? We need you. I mean — we need you.”

She got up and left the room.

His next project was more complex. Although Peter was confident, the Vishniac people were dubious. Sax explained as best he could. Peter helped. Their objections turned to practicalities. Too large? Enlist more Bogdanovists. Impossible to stealth? Interrupt the surveillance network. Science is creation, he told them. This isn’t science, Peter replied. It’s engineering. Mikhail agreed, but liked that part of it. Ecotage, a branch of ecological engineering. But very difficult to arrange. Enlist the Swiss, Sax told them. Or at least let them know. They don’t like surveillance anyway. Tell Praxis.