They were sending their few unburned trains to Libya Station, as were many other cities. The nearest were also sending planes and dirigibles. The dirigibles would be able to come to their aid during the night’s march, which was useful. Especially important would be any water they could bring with them, as dehydration in the cold and hyperarid night was going to be severe. Nadia’s throat was already parched, and she happily took a cupful of warm water from a passing rover handing them out. She lifted her mask and drank swiftly, trying not to breathe as she did. “Last call!” the woman passing out the cups called cheerily. “We’ll run out after the next hundred people.”

Another kind of call came in from South Fossa. They had heard from several mining camps around Elysium, whose occupants had declared themselves independent of both the metanationals and the Free Mars movement, and were warning everyone to stay away. .Some stations occupied by Reds were doing much the same. Nadia snorted. “Tell them fine,” she said to the people in South Fossa. “Send them a copy of the Dorsa Brevia Declaration, and tell them to study it for a while. If they’ll agree to uphold the human rights section, I don’t see why we should bother with them.”

The sun set as they walked. The long twilight slowly ran its course.

While there was still a dark purple twilight suffusing the hazy air, a boulder car drove up from the east and stopped just ahead of Nadia’s group, and figures got out and walked over to them, wearing white masks and hoods. By silhouette alone Nadia recognized, all of a sudden, the one in the lead: it was Ann, tall and spare, walking right up to her, picking her out of the rabble at the tail end of the column without hesitation, despite the lack of light. The way the First Hundred knew each other…

Nadia stopped, stared up at her old friend. Ann was blinking at the sudden cold.

“We didn’t do it,” Ann said brusquely. “The Armscor unit came out in armored cars, and there was a real fight. Kasei was afraid that if they retook the dike they would try to retake everything, everywhere. He was probably right.”

“Is he okay?”

“I don’t know. A lot of people on the dike were killed. And a lot had to escape the flood by going up onto Syrtis.”

She stood there before them, grim, unapologetic — Nadia marveled that one could read so much from a silhouette, a black cutout against the stars. Set of the shoulders, perhaps. Tilt of the head.

“Come on then,” Nadia said. There was nothing else she could think to say, at this point. Going out onto the dike in the first place, setting the explosive charges … but there was no point, now. “Let’s keep walking.”

The light leaked away from the land, out of the air, out of the sky. They hiked under the stars, through air as cold as Siberia. Nadia could have gone faster, but she wanted to stay at the back with the slowest group, to do what she could to help. People were giving piggyback rides to some of the smaller children among them, but the fact was there weren’t very many children at the end of the column; the smallest ones were already in rovers, and the older ones were up front with the faster walkers. There hadn’t been that many children in Burroughs to begin with.

Rover headlight beams cut through the dust they were throwing into the air, and seeing it Nadia wondered if the CO₂ filters would get clogged by fines. She mentioned this aloud, and Ann said, “If you hold the mask to your face and blow out hard, it helps. You can also hold your breath and take it off, and blow compressed air through it, if you have a compressor.”

Sax nodded.

“You know these masks?” Nadia said to Ann.

Ann nodded. “I’ve spent many hours using ones like them.”

“Okay, good.” Nadia experimented with hers, holding the fabric right against her mouth and blowing put hard. Quickly she felt short of breath. “We still should Tfy^walking on the piste and the roads, and cutting down on the dust. And tell the rovers to go slow.”

They walked on. Over the next couple of hours they fell into a kind of rhythm. No one passed them, no one fell back. It got colder and colder. Rover headlights partially illuminated the thousands of people ahead of them, all the way up the long gradual slope to the high southern horizon, which was perhaps twelve or fifteen kilometers ahead of them, it was hard to tell in the dark. The column ran all the way to the horizon: a bobbing, fencing collection of headlight beams, flashlight beams, the red glow of taillights … a strange sight. Occasionally there was a buzz overhead, as dirigibles from South Fossa arrived, floating like gaudy UFOs with all their running lights on, their engines humming as they wafted down to drop off loads of food and water for the cars to retrieve, and pick up groups from the back of the column. Then they hummed up into the air and away, until they were no more than colorful constellations, disappearing over the horizon to the east.

During the timeslip a crowd of exuberant young natives tried to sing, but it was too cold and dry, and they did not persist for long. Nadia liked the idea, and in her mind she sang some of her old favorites many times: “Hello Central Give Me’ Dr. Jazz,” “Bucket’s Got a Hole in It,” “On the Sunny Side of the Street.” Over and over and over.

The longer the night went on, the better her mood became; it was beginning to seem like the plan was going to work. They were not passing hundreds of prostrate people^although the word from the cars was that a fair number of the young natives appeared to have blown it and gone out too fast, and were now requiring assistance. Everyone had gone from 500 millibars to 340, which was the equivalent of going from 4,000 meters altitude on Earth to 6,500 meters, not an inconsiderable jump even with the higher percentage of oxygen in the Martian air to mitigate the effects; thus people were coming down with altitude sickness. Altitude sickness tended to strike the young a bit more than the old anyway, and many of the natives had taken off very enthusiastically. So some were paying for it now, with headaches and nausea felling quite a few. But the cars reported success so far taking in the ones on the edge of vomiting, and escorting the rest. And the rear of the column was keeping a steady pace.

So Nadia trudged on, sometimes hand in hand with Maya or Art, sometimes in her own world, her mind wandering in the biting cold, remembering odd shards of the past. She remembered some of the other dangerous cold walks she had taken over the surface of this world of hers: out in the great storm with John at Rabe Crater … searching for the transponder with Arkady … following Frank down into Noctis Labyrinthus, on the night they escaped from the assault on Cairo… On that night too she had fallen into an odd bleak cheerfulness — response to a freeing from responsibility, perhaps, to becoming no more than a foot soldier, following someone else’s lead. Sixty-one had been such a disaster. This revolution too could devolve into chaos — indeed it had. No one in control. But there were still voices coming in over her wrist, from everywhere. And no one was going to strafe them from space. The most intransigent elements of the Transitional Authority had probably been killed outright, in Kasei Vallis — an aspect of Art’s “integrated pest management” that was no joke. And the rest of UNTA was being overwhelmed by sheer numbers. They were incapable, as anyone would be, of controlling a whole planet of dissidents. Or too intimidated to try.

So they had managed to do it differently this time. Or else conditions on Earth had simply changed, and all the various phenomena of Martian history were only distorted reflections of those changes. Quite possible. A troubling thought, when considering the future. But that was for later. They would face all that when they came to it. Now they only had to worry about getting to Libya Station. The sheer physicality of the problem, and of the solution to the problem, pleased her immensely. Finally something she could get her hands on. Walk. Breathe the frigid air. Try’ to warm her lungs from the rest of her, from the heart — something like Nirgal’s uncanny heat redistribution, if only she could!