“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. Kasei’s 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 Chasmas. Michel called this area the Compton Break. It was chaotic terrain, and until they had crossed it, and gotten down into Ius Chasma, Michel would not feel comfortable. For without their rough 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 500 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.”
So he and Kasei began driving round the clock, taking shifts of three hours at the wheel followed by a half hour off. Another day and they were down the Compton Break, and into tight-walled Ius Chasma, and Michel relaxed.
Ius was the narrowest of all the canyons in the Marineris system, only twenty-five kilometers wide when it left the Compton Break, dividing Sinai Planum from Tithania Catena. The canyon was a deep slash between these two plateaus, its side cliffs a full three kilometers high; a long, narrow giant of a rift. But they only saw the walls in glimpses, through bubbles of open air in the blowing dust. They continued to follow a level but rock-strewn route, making good progress through all of a long dim day. It was quiet in the car, the radio turned down to decrease the irritation of the static. The cameras’ views, higher than the windows, were of dust whipping past them so that it seemed they hardly moved. Often it looked as if they were slewing sideways. It was hard driving, and Simon and Sax spelled Michel and Kasei, following their directions. Ann was still not talking, and they did not ask her to drive. Sax drove with one eye on his AI screen, which was giving him atmospheric readouts. She could tell from across the car that the AI was indicating that the impact of Phobos was thickening the atmosphere a great deal, projected to as much as a fifty-millibar addition, an extraordinary amount. And the newly smashed craters were still outgassing. Sax noted this change with his owlish satisfaction, oblivious to the death and destruction that came with it. He noticed her glare and said, “Like the Noachian Age, I suppose.” He nearly added more, but Simon silenced him with a look, and changed the subject.