Slowly the wind tattered the dust away. Her companions cheered; the water station was gone, covered by a fresh black landslide that spilled out from the northern wall, which now had a big new arc in its rim. But it had been a close thing, not anywhere near as big a landslide as she would have hoped; Lasswitz itself was still there, and it appeared that the layer of rock over the water station was not all that thick. The flood seemed to have stopped, it was true; it was motionless, a chunky, dirty white swath, like a glacier running down the middle of the canyon. And there was very little frost steam rising from it. Still…

“Let’s go back down to Lasswitz and look at the aquifer monitors,” Nadia said.

They drove back down the canyon wall road and into Lasswitz’s garage. They walked down the empty streets in walkers and helmets. The aquifer study center was located next to the city offices. It was odd to see their refuge of the last few days empty.

Inside the aquifer center they studied the readouts from the array of underground sensors. A lot of them were no longer functioning, but those that were showed that hydrostatic pressure inside the aquifer was higher than ever before, and increasing. As if to emphasize the point a small tremblor shook the ground, vibrating the soles of their boots. None of them had ever felt such a thing on Mars before. “Shit!” Yeli said, “it’s going to blow again for sure!”

“We have to drill a runoff well,” Nadia said. “A kind of pressure valve.”

“But what if it breaks out like the main one?” Sasha asked.

“If we put it at the upper end of the aquifer, or midway so that it takes some flow, it should be fine. Just as good as the old water station, which someone probably blew up, or else it would still be working fine.” She shook her head bitterly. “We have to risk it. If it works, it works. If it doesn’t, then maybe we cause an outbreak. But if we don’t do something, it looks like there’ll be an outbreak anyway.”

She led the little group down the main streeet to the robot warehouse in the garage, and sat down in the command center to begin programming again. A standard drilling operation, with maximum blowout baffling. The water would come to the surface under artesian pressure, and then they would direct it into a pipeline, which they would instruct a robot crew to lay in some direction that would take it out of the Arena canyon region. She and the others studied topographic maps, and ran simulated floods down several canyons paralleling Arena to north and south. They found that the watershed was huge, everything on Syrtis drained down toward Burroughs, the land was a big bowl here. They would have to pipe the water north for nearly three hundred kilometers to get it into the next watershed. “Look,” Yeli said, “released into the Nili Fossae, it will run straight north onto Utopia Planitia, and freeze on the northern dunes.”

“Sax must be loving this revolution,” Nadia said again. “He’s getting stuff they never would have approved.”

“But a lot of his projects must be getting wrecked too,” Yeli pointed out.

“I bet it’s still a net gain, in Sax’s terms. All this water on the surface…”

“We’ll have to ask him.”

“If we ever see him again.”

Yeli was silent. Then he said: “Is it that much water, really?”

“It’s not just Lasswitz,” Sam said. “I saw a news bit a while ago-they’ve broken the Lowell aquifer, a big breakout like the ones that cut the outflow channels. It’ll rip billions of kilos of regolith downslope, and I don’t know how much water. It’s unbelievable.”

“But why? ” Nadia said.

“It’s the best weapon they have, I guess.”

“Not much of a weapon! They can’t aim it or stop it!”

“No. But neither can anyone else. And think about it-all the towns downslope from Lowell are gone-Franklin, Drexler, Osaka, Galileo, I imagine even Silverton. And all those were transnational towns. A lot of channel mining towns are vulnerable, I should think.”

“So both sides are attacking the infrastructure,” Nadia said dully.

“That’s right.”

She had to work, there was no other choice. She got them going again on robot programming, and they spent the rest of that day and the next getting the robot teams out to the drilling site, and making sure the start-up went right. The drilling was straightforward; it was only a matter of making sure that pressures in the aquifer didn’t cause a blowout. And the pipeline to transfer the water north was even simpler, an operation that had been fully automated for years; but they doubled up on all the equipment, just to make sure. Up the north canyon road bed, and on northward from there. No need to include pumps; artesian pressure would regulate the flow quite nicely, because when the pressure dropped low enough to stop pushing water out of the canyon, the danger of a breakout at the lower end would presumably be past. So when the mobile magnesium mills were grinding along, scooping up fines and making pipe, and when the forklifts and frontloaders were taking these pipe segments to the assembler, and when that great moving building was taking in the segments and extruding pipe behind it as it rolled slowly along up the road, and when another mobile behemoth was going over the completed pipe, and wrapping it in aerolattice insulation made from tailings from the refinery; and when the first segment of the pipline was heated and running-then they declared the system operational, and hoped it would make it three hundred kilometers farther. The pipeline would be built at about a kilometer an hour, for twenty-four and a half hours a day; so if all went well, about twelve days to Nili Fossae. At that rate the pipeline would be done very soon after the well was drilled and ready. And if the landslide dam held that long, then they would have their pressure valve.

So Burroughs was safe, or as safe as they could make it by their efforts. They could go. But it was a question what their destination should be. Nadia sat slumped over a microwaved dinner, watching a terran news show, listening to her companions debate the issue. Horrible how the revolution was being portrayed on Earth: extremists, communists, vandals, saboteurs, reds, terrorists. Never the words rebel or revolutionary, words of which half the Earth (at least) might approve. No, they were isolated groups of insane, destructive terrorists. And it didn’t help Nadia’s mood that there was, she felt, some truth to the description; it only made her angrier.

“We should join whoever we can, and help fight!” Angela said.

“I’m not fighting anyone,” Nadia said mulishly. “It’s stupid. I won’t do it. I’ll fix things where I can, but I won’t fight.”

A message came over the radio. Fournier Crater, about eight hundred and sixty kilometers away, had a cracked dome. The populace was trapped in sealed buildings, and running out of air.

“I want to go there,” Nadia said. “There’s a big central warehouse of construction robots there. They could fix the dome, and then be set to other repairs down on Isidis.”

“How will you get there?” Sam asked.

Nadia thought it over, took a deep breath. “Ultralite, I guess. There’s some of those new 17Ds up on the south rim airstrip. That would be the fastest way for sure, and maybe even the safest, who knows.” She looked at Yeli and Sasha. “Will you fly with me?”

“Yes,” Yeli said. Sasha nodded.

“We want to come with you,” Angela said. “It’ll be safer with two planes anyway.”

They tooktwo planes that had been built by Spencer’s aeronautic factory in Elysium, the latest things, called simply 17Ds, ultralite delta-winged four-seat turbojets, made mostly of aerogel and plastics, dangerous to fly because they were so light. But Yeli was an expert flier and Angela said she was too, so they climbed into two of them the next morning, after spending the night in the empty little airport, and taxied out to the packed dirt runway and took off directly into the sun. It took them a long time to rise to a thousand meters.