On Earth the situation was less clear. The Subarashii metanats were still struggling with the southern metanats, but in the context of the great flood they had become a bitter sideshow. It was hard to tell what Terrans in general thought of the conflict on Mars.

Whatever they thought, a fast shuttle was about to arrive, with reinforcements for security. So resistance groups from all over mobilized to converge on Burroughs. Art did what he could to help this effort from inside Burroughs, locating all the people who had independently thought of coming (it was obvious, after all), telling them their idea was good, and siccing them on people opposed to the plan. He was, Nadia thought, a subtle diplomat — big, mild, unpretentious, unassuming, sympathetic, “undiplomatic” — head lowered as he conferred with people, giving them the impression they were the ones driving the process. Indefatigable, really. And very clever. Soon he had a great number of groups coming, including the Reds and the Marsfirst guerrillas, who still appeared to be thinking of their approach as a kind of assault, or siege. Nadia felt acutely that while the Reds and Marsfirsters she knew — Ivana, Gene, Raul, Kasei — were keeping in touch with her, and agreeing to the use of her as an arbitrator, there were more radical Red and Marsfirst units out there for whom she was irrelevant, or even an obstruction1. This made her angry, because she was sure that if Ann was fully supporting her, the more radical elements would come around. She complained bitterly about this to Art, after seeing a Red communique arranging the western half of the “convergence” on Burroughs, and Art went to work and got Ann to answer a call, then gave her over in a link to Nadia.

And there she was again, like one of the furies of the French Revolution, as bleak and grim as ever. Their last exchange, over Sabishii, lay heavy between them; the issue had become moot when UNTA retook Sabishii and burned it down, but Ann was obviously still angry, which Nadia found irritating.

Brittle greetings over, their conversation degenerated almost instantly into argument. Ann clearly saw the revolt as a chance to wreck all terraforming efforts and to remove as many cities and people as possible from the planet, by direct assault if necessary. Frightened by this apocalyptic vision, Nadia argued with her bitterly, then furiously. But Ann had gone off into a world of her own. “I’d be just as happy if Burroughs did get wrecked,” she declared coldly.

Nadia gritted her teeth. “If you wreck Burroughs you wreck everything. Where are the people inside supposed to go? You’ll be no better than a murderer, a mass murderer. Simon would be ashamed.”

Ann scowled. “Power corrupts, I see. Put Sax on, will you? I’m tired of this hysteria.”

Nadia switched the call to Sax and walked away. It was not power that corrupted people, but fools who corrupted power. Well, it could be that she had been too quick to anger, too harsh. But she was frightened of that dark place inside Ann, the part that might do anything; and fear corrupted more than power. Combine the two…

Hopefully she had shocked Ann severely enough to squeeze that dark place back into its corner. Bad psychology, as Michel pointed out gently, when Nadia called him in Burroughs to talk about it. A strategy resulting from fear. But she couldn’t help it, she was afraid. Revolution meant shattering one structure and creating another one, but shattering was easier than creating, and so the two parts of the act were not necessarily fated to be equally successful. In that sense, building a revolution was like building an arch; until both columns were there, and the keystone in place, practically any disruption could bring the whole thing crashing down.

So on Wednesday evening, five days after Nadia’s call from Sax, about a hundred people left for Burroughs in planes, as the pistes were judged too vulnerable to sabotage. They flew overnight to a rocky landing strip next to a large Bogdanovist refuge in the wall of Du Martheray Crater, which was on the Great Escarpment southeast of Burroughs. They landed at dawn, with the sun rising through mist like a blob of mercury, lighting distant ragged white hills to the north, on the low plain of Isidis: another new ice sea, whose progress south had been stopped only by the arcing line of the dike, curving across the land like a long low earthen dam — which was just what it was.

To get a better view Nadia went up to the top floor of the Du Martheray refuge, where an observation window, disguised as a horizontal crack just under the rim, gave a view down the Great Escarpment to the new dike and the ice pressing against it. For a long time she stared down at the sight, sipping coffee mixed with a dose of kava. To the north was the ice sea, with its clustered seracs and long pressure ridges, and the flat white sheets of giant frozen-topped melt lakes. Directly below her lay the first low hills of the Great Escarpment, dotted with spiky expanses of Acheron cacti, sprawling over the rock like coral reefs. Staircased meadows of black-green tundra moss followed the courses of small frozen streams dropping down the Escarpment; the streams in the distance looked like long algae diatoms, tucked into creases in the redrock.

And then in the middle distance, dividing desert from ice, ran the new dike, like a raw brown scar, suturing two separate realities together.

Nadia spent a long time studying it through binoculars. Its southern end was a regolith mound, running up the apron of Crater Wg and ending right at Wg’s rim, which was about half a kilometer above the datum, well above the expected sea level. The dike ran northwest from Wg, and from her prospect high on the Escarpment Nadia could see about forty kilometers of it before it disappeared over the horizon, just to the west of Crater Xh. Xh was surrounded by ice almost to its rim, so that its r6und interior was like an odd red sinkhole. Everywhere else the ice had pressed right up against the dike, for as far as Nadia could see. The desert side of the dike appeared to be some two hundred meters high, although it was difficult to judge, as there was a broad trench underneath the dike. On the other side, the ice bulked quite high, halfway up or more.

The dike was about three hundred meters wide at the top. That much displaced regolith — Nadia whistled respectfully — represented several years of work, by a very large team of robot draglines and canal-diggers. But loose regolith! It seemed to her that huge as the dike was on any human scale, it was still not much to contain an ocean of ice. And ice was the easy part — when it became liquid, the waves and currents would tear regolith away like dirt. And the ice was already melting; immense melt pods were said to lie everywhere underneath the dirty white surface, including directly against the dike, seeping into it.

“Aien’t they’re going to have to replace that whole mound with concrete?” she said to Sax, who had joined her, and was looking through his own binoculars at the sight.

“Face it,” he said. Nadia prepared herself for bad news, but he continued by saying, “Face the dike with a diamond coating. That would last fairly long. Perhaps a few million years.”

“Hmm,” Nadia said. It was probably true. There would be seepage from below, perhaps. But in any case, whatever the particulars, they would have to maintain the system in perpetuity, and with no room for error, as Burroughs was just 20 kilometers south of the dike, and some 150 meters lower than it. A strange place to end up. Nadia trained her binoculars in the direction of the city, but it lay just over her horizon, about 70 kilometers to the northwest. Of course dikes could be effective; Holland’s dikes had held for centuries, protecting millions of people and hundreds of square kilometers, right up until the recent flood — and even now those great dikes were holding, and would be broached first by flanking floods through Germany and Belgium. Certainly dikes could be effective. But it was a strange fate nevertheless.