Quite a few dorsa were hollow, their hosts told them. Lava tunnels. There were many of them on Terra, but the usual two-magnitude scale jump obtained, and this tube was in fact a hundred times bigger than the biggest Terran tube. When the lava streams had flowed, a young woman named Ariadne explained to Art, they had cooled and hardened at their edges, and then on their surfaces — after which hot lava had continued to run through the sleeve, until the flows had stopped, and the remaining lava had emptied out onto some lake of fire, leaving behind cylindrical caves that were sometimes fifty kilometers long.

The floor of this particular tunnel was approximately flat, and now it was covered by rooftops and grassy parks, ponds, and hundreds of young trees, planted in groves of mixed bamboo and pine. Long cracks in the roof of the tunnel had served as the basis for filtered skylights, made of layered materials which gave off the same visual and thermal signals as the rest of the ridge, but let into the tunnel long curtains of sunny brown air, so that even the dimmest sections of the tunnel were only as dim as a cloudy day.

Dorsa Brevia’s tunnel was forty kilometers long, Ariadne informed them as they walked down a staircase, although there were places where the roof had caved in, or plugs of lava almost filled the cavity. “We haven’t closed off the whole thing, of course. It’s more than we need, and more than we could keep warm and pumped anyway. But we’ve closed off about twelve kilometers now, in kilometer-long segments, with tent-fabric bulkheads between them.”

“Wow,” Art said again. Nirgal felt just as impressed, and Nadia was clearly delighted. Even Vishniac was nothing compared to this.

Jackie was already near the bottom of the long staircase that led from the garage lock to a park below them. As they followed her Art said, “Every colony you’ve taken me to I’ve figured has to be the biggest one, and I’m always wrong. Why don’t you just tell me now if the next one is going to be like all of Hellas Basin or something.”

Nadia laughed. “This is the biggest one I know of. Bigger!”

“So why do you all stay in Gamete, when it’s so cold and small and dim? Couldn’t the people from all the sanctuaries fit into this space?”

“We don’t want to all be in one place,” she replied. “As for this one, it wasn’t even here a few years ago.”

Down on the floor of the tunnel they appeared to be in a forest, under a black stone sky rent by long jagged bright cracks. The four travelers followed a group of their hosts to a complex of buildings with thin wooden walls and steep roofs upturned at the corners. In one of these they were introduced to a group of elderly women and men in colorful baggy clothing, and invited to share a meal.

As they ate they learned more about the sanctuary, mostly from Ariadne, who sat beside them. It had been built and occupied by the descendants of people who had come to Mars and joined the disappeared in the 2050s, leaving the cities and occupying small refuges in this region, aided in their efforts by the Sabishiians. They had been heavily influenced by Hiroko’s areophany, and their society was described by some as a matriarchy. They had studied some ancient matriarchal cultures, and based some of their customs on the ancient Minoan civilization and the Hopi of North America. Thus they worshipped a goddess who represented life on Mars, something like a personification of Hiroko’s viriditas, or a deification of Hiroko herself. And in daily life the women owned the households, and would pass them on to their youngest daughters: ultimogeniture, Ariadne called it, a custom of the Hopi. And as with the Hopi, men moved into their wives’ houses on marriage.

“Do the men like it?” Art asked curiously.

Ariadne laughed at his expression. “There’s nothing like happy women for making happy men, that’s what we say.” And she gave Art a look that seemed to pull him right over the bench toward her.

“Makes sense to me,” Art said.

“We all share the work — extending the tunnel segments, farming, raising the children, whatever needs doing. Everybody tries to get good at more than just their specialty, which is a custom that comes from the First Hundred, I think, and the Sabishiians.”

Art nodded. “And how many of you are there?”

“About four thousand now.”

Art whistled his surprise.

That afternoon they were taken down the tunnel through several kilometers of transformed segments, many of them forested, and all containing a large stream that ran down the floor of the tunnel, widening in some segments to form big ponds. When Ariadne brought them back up to the first chamber, called Zakros, almost a thousand people showed up for an open-air meal in the largest park. Nirgal and Art wandered around talking to people, enjoying a plain meal of bread and salad and broiled fish. The people there appeared receptive to the idea of a congress of the underground. They had tried something like it years before, but had not gotten many takers at the time — had lists of the sanctuaries in their region — and one of the older women said, with authority, that they would be happy to host it, as they had a space large enough to handle a great number of guests.

“Oh, that would be marvelous,” Art said, glancing at Ariadne.

Later Nadia agreed. “It will help a lot,” she said. “A lot of people will be resistant to the idea of a meeting, because they suspect the First Hundred of trying to take charge of the underground. But if it’s held here, and the Bogdanovists are behind it…”

When Jackie came over and heard of the offer, she gave Art a hug. “Oh, it’s going to happen! And it’s just what John Boone would have done. It’s like the meeting he called on Olympus Mons.”

They left Dorsa Brevia and headed north again, on the east side of the Hellas Basin. During the nights of this drive Jackie often brought out John Boone’s AT, Pauline, which she had studied and cataloged. She played back selections from his thoughts about an independent state, thoughts disorganized and rambling, the reflections of a man with more enthusiasm (and omegendorph) than analytic ability; but sometimes he would get on a roll, and ad-lib in the manner of the famous speeches, and that could be fascinating. He had had a knack for free association which made his ideas sound like logical progression even when they weren’t.

“See how often he talks about the Swiss,” Jackie said. She sounded like John, Nirgal noticed suddenly. She had been working with Pauline extensively for a long time, and her manner had been affected by it. John’s voice, Maya’s manner; in such ways they carried the past with them. “We have to make sure some Swiss are at the congress.”

“We’ve got Jurgen and the group at Overhangs,” Nadia said.

“But they’re not really so Swiss, are they?”

“You’ll have to ask them,” Nadia said. “But if you mean Swiss officials, there are a lot of them in Burroughs, and they’ve been helping us there, without ever even talking to us about it. About fifty of us have Swiss passports now. They’re a big part of the demimonde.”

“As is Praxis,” Art put in.

“Yes yes. Anyway, we’ll talk to the group at Overhangs. They’ll have contacts with the surface Swiss, I’m sure.”

Northeast of the volcano Hadriaca Patera, they visited a town that had been founded by Sufis. The original structure was built into the side of a canyon cliff, in a kind of high-tech Mesa Verde — a thin line of buildings, inserted into the break point where the cliffs imposing overhang began to slope back out and down to the canyon floor. Steep staircases in walktubes ran down the lower slope to a small concrete garage, and around the garage had sprung up a number of blister tents and greenhouses. These tents were occupied by people who wished to study with the Sufis. Some came from the sanctuaries, some from the cities of the north; many were natives, but quite a few were newcomers from Earth. Together they hoped to roof the entire canyon, using materials developed for the new cable to support an immense spread of tent fabric. Nadia was immediately drawn into discussions of the construction problems such a project would encounter, which she happily told them would be various and severe. Ironically, the thickening atmosphere made all dome projects more difficult, because the domes could not be floated by the air pressures underneath them to the extent they once had been; and though the tensile and load-bearing strengths of the new carbon configurations were more than they would need, anchoring points that would hold such weights as they had in mind would be almost impossible to find. But the local engineers were confident that lighter tent fabrics and new anchoring techniques might serve, and the walls of the canyon, they said, were solid. They were in the very upper reach of Reull Vallis, and ancient sapping had cut back into very hard material. Good anchoring points should be everywhere.