* * *

Some mistakesyou can never make good.

Ann Clayborne sat in the back of Michel’s rover, sprawled across three seats, feeling the wheels rise and fall over the rocks. Her mistake had been in coming to Mars in the first place, and then falling in love with it. Falling in love with a place everyone else wanted to destroy.

Outside the rover, the planet was being changed forever. Inside, the main room was lit by floor-level windows, which gave a snake’s eye view out under the skirt of the rover’s stone roof. Rough gravel road, scattered rockfall in the way. They were on the Noctis Highway, but a lot of rock had fallen on it. Michel wasn’t bothering to drive around the smaller samples; they rolled along at about sixty kmph, and when they hit a big one they all jounced in their seats. “Sorry,” Michel said. “We have to get out of the Chandelier as soon as possible.”

“The Chandelier?”

“Noctis Labyrinthus.”

The original name, Ann knew, given to it by the terran geologists staring at Mariner photos. But she didn’t speak. The will to speech had left her.

Michel talked on, his voice low and conversation, reassuring. “There’s several places where if the road were cut it would be impossible to get the cars down. Transverse scarps that run from wall to wall, giant boulder fields, that kind of thing. Once we get into Marineris we’ll be okay, there’s all kinds of cross-country routes there.”

“Are these cars supplied for a drive down the whole canyon?” Sax asked.

“No. We’ve got caches all over the place, though.” Apparently the great canyons had been some of the principal transport corridors for the hidden colony. When the official Canyon Highway was built it had caused them problems, cutting off a lot of their routes.

From her corner Ann listened to Michel as attentively as the rest; she couldn’t help being curious about the hidden colony. Their use of the canyons was ingenious. Rovers designed to stay down in them were disguised to look like one of the millions of boulders that lay in great talus piles sloping out from the cliffs. The roofs of the cars actually were boulders, hollowed out from below. Heavy insulation kept the rock roof of the car from heating up, so there was no IR signal, “especially since there’s still any number of Sax’s windmills scattered around down here, and they confuse the picture.” The rover was insulated on its underside as well, so that it left no snail’s track of heat to reveal its passing. The heat from the hydrazine motor was used to warm the living quarters, and any excess was directed into coils for later use; if they built up too much while moving, the coils were dropped into holes dug under the car, and buried with regolith mixed with liquid oxygen. By the time the ground over the coil warmed up, the rover was long gone. So they left no heat signal, and they never used the radio, and they moved only at night. During the day they sat in place among other boulders, “and even if they compared daily photos and saw we were new in the area, we would just be one in a thousand new boulders that had fallen off the cliffs that night. Mass wasting has really accelerated since you started the terraforming, because it’s freezing and thawing every day. In the mornings and evenings there’s something coming down every few minutes.”

“So there’s no way they can see us,” Sax said, sounding surprised.

“That’s right. No visual signal, no electronic signal, no heat signal.”

“A stealth rover,” Frank said over the intercom from the other car, and laughed his harsh bray.

“That’s right. The real danger down here is the very rockfall that’s hiding us.” A red light on the dash went off, and Michel laughed. “We’re going so well we’ll have to stop and bury a coil.”

“Won’t it take a while to dig a hole?” Sax said.

“There’s one already dug, if we can get to it. Another four kilometers. I think we’ll make it.”

“You have quite a system here.”

“Well, we’ve been living underground for fourteen years now, fourteen martian years I mean. Thermal disposal engineering is a big thing for us.”

“But how do you do it for your permanent habitats, assuming you have any?”

“We pipe it down into the deep regolith, and melt ice for our water. Or else we pipe it out to vents disguised as your little windmill heaters. Among other methods.”

“Those were a bad idea,” Sax said. From the next car Frank laughed at him. Only thirty years late with that realization, Ann would have said if she were speaking.

“But no, an excellent idea!” Michel said. “They must have added millions of kilocalories to the atmosphere by now.”

“About an hour from any of the moholes,” Sax said primly.

He and Michel began to discuss the terraforming projects. Ann let their voices drift into glossolalia; it was amazingly easy, conversations these days were always right on the edge of meaninglessness for her, she had to exert herself to understand, rather than the reverse. She relaxed away from them, and felt Mars bounce and jumble under her. They stopped briefly to bury a heating coil. The road got smoother when they started again. They were deep in the labyrinth now, and in a normal rover she would have been looking through the skylights at tight steep canyon walls. Rift valleys, enlarged by slumping; there had been ice in this ground, once upon a time, now all migrated down to the Compton aquifer at the bottom of Noctis, presumably.

Ann thought of Peter and shuddered helplessly. One couldn’t assume things, but the fear gnawed at her. Simon watched her surreptitiously, the worry plain on his face, and suddenly she hated his doggy loyalty, his doggy love. She didn’t want anyone to care for her like that, it was an unbearable burden, an imposition.

At dawn they stopped. The two boulder rovers parked at the edge of a patch of similar boulders. All day they sat in one of the cars together, lingering over small rehydrated or microwaved meals, trying to find TV or radio transmissions. There weren’t any to speak of, only the occasional burst in a number of languages and encryptions. An ether junkyard, adding up to an incoherent mash. Harsh blasts of static seemed to indicate electromagnetic pulses. But the rover’s electronics were hardened, Michel said. He sat in a chair as if meditating. A new calm for Michel Duval, Ann thought. As if he were used to waiting out his days in hiding. His companion, the youth driving the other car, was named Kasei. His voice had a permanent tone of grim disapproval. Well, they deserved it. In the afternoon Michel showed Sax and Frank where they were, on a topo map he clicked onto both cars’ screens. Their route through Noctis was to run a course southwest to northeast, along one of the biggest canyons of the labyrinth; emerging from that it zigzagged eastward, dropping steeply until they were at the big area between Noctis and the heads of Ius and Tithonium Chasms. Michel called this area the Compton Break, and it was chaotic terrain; and until they had crossed it, and gotten down into Ius Chasm, Michel would not feel comfortable. For without their surreptitious road, he said, the area was basically impassable. “And if they figure we went this way out of Cairo, they may bomb the route.” They had traveled nearly five hundred kilometers the previous night, almost the whole length of Noctis; another good night and they would be down into Ius, and beyond their complete reliance on a single route.

It was a dark day, the air thick with brown fines, the winds high. Another dust storm, no doubt about it. Temperatures were plummeting. Sax sniffed at a radio voice which claimed the dust storm was going global. Michel, however, was pleased. It meant they could travel during the day as well, cutting their travel time in half. “We’ve got five thousand kilometers to go, and most of it off-road. It will be wonderful to be able to travel by day, I haven’t done that since the Great Storm.”