Sax shivered, thinking of his own recent brush with cold; and 260 millibars was the pressure one would find on the peak of Everest. The others were already talking about other famous blowouts, including the time Hiranyagarba’s dome had fallen in its entirety under an ice rain, despite which no one had died.

Then they were descending over the great cratered high plain of Xanthe, coming down on the Da Vinci crater floor’s big sandy runway, which they had just started using during the revolution. The whole community had been preparing for years for the day when stealthing would become unnecessary, and now a big curve of copper-mirrored windows had been installed in the arc of the southern crater rim. There was a layer of snow in the bottom of the crater, which the central knob broke out of quite dramatically. It was possible they could arrange for a lake in the crater floor, with a central knob island, which would have as its horizon the circling cliffy hills of the crater rim. A circular canal could be built just under the rim cliffs, with radial canals connecting it to the inner lake; the resulting alternation of circular water and land would resemble Plato’s description of Atlantis. In this configuration Da Vinci could support, in near self-sufficiency, some twenty or thirty thousand people, Sax guessed; and there were scores of craters like Da Vinci. A commune of communes, each crater a city-state of sorts, its polls fully capable of supporting itself, of deciding what kind of culture it might have; and then with a vote in a global council of some kind… No regional association larger than the level of the town, except for arrangements of local interchange… might it work?

Da Vinci made it seem like it might. The south arc of the rim was alive with arcades and wedge-shaped pavilions and the like, now all shot through with sunlight. Sax toured the whole complex one morning, visiting one lab after the next, and congratulating the occupants on the success of their preparations for a smooth removal of UNTA from Mars. Some political power came out of the end of a gun, after all, and some out of the look in the eye; and the look in the eye changed depending on whether a gun was pointed at it or not. They had spiked the guns, these people the saxaclones, and so they were in high spirits — happy to see him, and already looking for different work — back to basic research, or figuring out uses for the new materials that Spencer’s alchemists were constantly churning out; or studying the terraforming problem.

They were also paying attention to what was going on in space and on Earth. A fast shuttle from Earth, contents unknown, had contacted them requesting permission to make an orbital insertion without a keg of nails being thrown in its way. So a Da Vinci team was now nervously working out security protocols, in heavy consultation with the Swiss embassy, which had taken an office in a suite of apartments at the northwest end of the arc. From rebels to administrators; it was an awkward transition.

“What political parties do we support?” Sax asked.

“I don’t know. The usual array I guess.”

“No party gets much support. Whatever works, you know.”

Sax knew. That was the old tech position, held ever since scientists had become a class in society, a priest caste almost, intervening between the people and their power. They were apolitical, supposedly, like civil servants — empiricists, who only wanted things managed in a rational scientific style, the greatest good for the greatest number, which ought to be fairly simple to arrange, if people were not so trapped in emotions, religions, governments, and other mass delusional systems of that sort.

The standard scientist politics, in other words. Sax had once tried to explain this outlook to Desmond, causing his friend for some reason to laugh prodigiously, even though it made perfect sense. Well, it was a bit naive, therefore a bit comical, he supposed; and like a lot of funny things, it could be that it was hilarious right up to the moment it turned horrible. Because it was an attitude that had kept scientists from going at politics in any useful way for centuries now; and dismal centuries they had been.

But now they were on a planet where political power came out of the end of a mesocosm aerating fan. And the people in charge of that great gun (holding the elements at bay) were at least partly in charge. If they cared to exercise the power.

Gently Sax reminded people of this when he visited them in their labs; and then to ease their discomfort with the idea of politics, he talked to them about the terraforming problem. And when he finally got ready to leave for Sabishii, about sixty of them were willing to come with him, to see how things were going down there. “Sax’s alternative to Pavonis,” he heard one of the lab techs describe the trip. Which was not a bad thought.

Sabishii was located on the western side of a five-kilometer-high prominence called the Tyrrhena massif, south of Jarry-Desloges Crater, in the ancient highlands between Isidis and Hellas, centered at longitude 275 degrees, latitude 15 degrees south. A reasonable choice for a tent-town site, as it had long views to the west, and low hills backing it to the east, like moors. But when it came to living in the open air, or growing plants out in the rocky countryside, it was a bit high; in fact it was, if you excluded the very much larger bulges of Tharsis and Elysium, the highest region on Mars, a kind of bioregion island, which the Sabi-shiians had been cultivating for decades.

They proved to be severely disappointed by the loss of the big mirrors, one might even say thrown into emergency mode, an all-out effort to do what they could to protect the plants of the biome; but it was precious little. Sax’s old colleague Nanao Nakayama shook his head. “Winterkill will be very bad. Like ice age.”

“I’m hoping we can compensate for the loss of light,” Sax said. “Thicken the atmosphere, add greenhouse gases — it’s possible we could do some of that with more bacteria and suralpine plants, right?”

“Some,” Nanao said dubiously. “A lot of niches are already full. The niches are quite small.”

They settled in over a meal to talk about it. All the techs from Da Vinci were there in the big dining hall of The Claw, and many Sabishiians were there to greet them. It was a long, interesting, friendly talk. The Sabishiians were living in the mound maze of their mohole, behind one talon of the dragon figure it made, so that they didn’t have to look at the burned ruins of their city when they weren’t working on it. The rebuilding was much reduced now, as most of them were out dealing with the results of the mirror loss. Nanao said to Tariki, in what was clearly the continuation of a long-standing argument, “It makes no sense to rebuild it as a tent city anyway. We might as well wait, and build it in open air.”

“That may be a long wait,” Tariki said, glancing at Sax. “We’re near the top of the viability atmosphere named in the Dorsa Brevia document.”

Nanao looked at Sax. “We want Sabishii under any limit that is set.”

Sax nodded, shrugged; he didn’t know what to say. The Reds would not like it. But if the viable altitude limit was raised a kilometer or so, it would give the Sabishiians this massif, and make little difference on the larger bulges — so it seemed to make sense. But who knew what they would decide on Pavonis? He said, “Maybe we should focus now on trying to keep atmospheric pressures from dropping.”

They looked somber.

Sax said, “You’ll take us out and show us the massif?”

They cheered up. “Most happy.”

The land of the Tyrrhena massif was what the areologists in the early years had called the “dissected unit” of the southern highlands, which was much the same as the “cratered unit,” but further broken by small channel networks. The lower and more typical highlands surrounding the massif also contained areas of “ridged unit” and “hilly unit.” In fact, as quickly became obvious the morning they drove out onto the land, all aspects of the rough terrain of the southern highlands were on view, often all at once: cratered, broken, uneven, ridged, dissected, and hilly land, the quintessential Noachian landscape. Sax and Nanao and Tariki sat on the observation deck of one of the Sabishii University rovers; they could see other cars carrying other colleagues, and there were teams out walking ahead of them. On the last hills before the horizon to the east, a few energetic people were fell-running. The hollows of the land were all lightly dusted with dirty snow. The massif was centered fifteen degrees south of the equator, and they got a fair bit of precipitation around Sabishii, Nanao said. The southeast side of the massif was drier, but here, the cloud masses pushed south over the ice in Isidis Planitia and climbed the slope and dropped their loads.