It was an awesome and claustrophobic experience. The mouth, hidden behind boulders on the side of a cliff, was an irregular hole barely large enough to wriggle through. It opened out into a large chamber. Just enough sunlight came in through the narrow opening to show that the floor held the charred logs of burned-out campfires and the shards of several dozen beer bottles. “Hey, we should have brought some beer,” Rip said. Shining their flashlights up, they saw the rock walls were covered with spray-painted names and dates. The oldest, “Dave” and “QT,” were written in charcoal. Dave and QT, whoever they were, must have been the first to discoverer the cave. At least their signatures, dated 2015, ten years ago, were the earliest dates on the wall.
Out of five of them, two had refused to venture any further into the cave than the distance that they could see the light from the mouth. The remaining three Brandon, Rip, and Kaipo—squeezed through a vertical cleft between two boulders at the back and into the real darkness. Only a few names were painted here, in smaller letters. In twenty feet, the passage had turned enough times that, with their flashlights off, it was pitch dark. “A maze of twisty, narrow passages, all alike,” Kaipo said.
It would have been smart of them to have brought a GPS, or even a compass, but they had not originally intended to go far into the cave. But none of the three of them wanted to be the one who suggested turning back. Instead, at each branching they marked their path on the walls with a piece of chalk that Rip had had the foresight to bring.
Carlsbad was only a hundred miles or so further on; they had all hoped that the unnamed cave they were exploring might have wonders to rival its vast chambers and arching pillars. But this one seemed to be a labyrinth of rough passages, branching and winding in all directions, only rarely opening into cramped, dome-ceilinged rooms. Sometimes they had to crawl on their bellies, and they never quite dared to stand fully upright. But when one passage came to a blind end, they always found a branch that went on, that might go on to open out into some large chamber just ahead.
After several hours, Kaipo admitted what they had all been thinking: That’s enough. Their flashlight beams were growing yellow, and by unspoken agreement they were already beginning to conserve, never shining more than one light at a time. They had better get back while they still had enough light in them to pick out the chalk marks. Rip quickly agreed, and the two of them turned and shone their flashlights back the way they’d come.
“Hey, why are you going that way?” Brandon had asked.
“The chalk marks, you dimwit,” Kaipo said.
“But—” He started to point, and then suddenly realized that it was senseless for him to point when none of them were shining their flashlights in his direction. “The entrance is just a little way over here,” he concluded.
“No way,” Kaipo said. “We’re miles away from the entrance by now.”
“You’re lost, Brandon,” Rip said.
“The hell I am.”
In the end, he convinced them to follow him a little way farther, probably for no other reason than that they wanted to gloat over him when he failed to get to the entrance. A hundred feet farther, they came into the chamber with the graffiti.
It had seemed no big deal to him. Over several hours, and several miles underground, through twisting passages, Brandon had always known unerringly where he was. On the surface of the Earth, for his entire seventeen years of life, Brandon’s sense of direction had never failed him, not even for a moment.
That was why Mars was such a shock.
3
At the Top
In fact, it had taken longer than expected to climb the cliff. Once at the top, it was their task to raise the rockhopper up, but the winching operation was slow and painstaking, and the sun touched the horizon with the rock-hopper less than halfway up. Rather than risk damaging it against an unseen protuberance, Ryan called a halt.
“Can we just leave it there, dangling like that?” Brandon asked.
“Sure, it’ll be fine,” Ryan said.
Brandon was still dubious. “What if the wind picks up over the night?”
“At this atmospheric pressure? Don’t worry about it. It would take a hurricane just to get it to budge.”
“What about earthquakes?”
Ryan laughed. “It will be fine, Trevor. Don’t worry.”
“Brandon,” he said.
“Oh, yeah. Right. I forgot. It will be fine, Brandon. Just fine. Don’t worry.”
As usual, in the morning Brandon was the first one up, and started the day by suiting up and walking around the campsite while the others were still getting up. This time Ryan didn’t even bother to remind him not to forget the suit checklist, and so Brandon was the first one to look down. The rover was covered by a fine white fuzz. He looked down at it in horror, for a moment too startled to speak. Then he keyed on his radio. “Ryan, come quick,” he called. “The rockhopper—it’s covered with mold!”
Ryan was checking the winch.
The rockhopper was easy to spot; it gleamed brilliantly white, almost bloody in the red morning sunlight. Fine, fuzzy tendrils seemed to grow out of it and reach up the invisible line of the superfiber cable. Ryan walked cautiously to the cliff edge and looked down. For a moment Ryan seemed disconcerted. Then he laughed. He went back to the winch.
“Well?” Brandon said. “What is it?”
“Frost,” Ryan said. “Only frost. No big deal.”
“Frost?” Brandon sounded doubtful. “Frost on Mars?”
Ryan spoke us he continued checking the winch. “The rover cooled down more than the rocks. Lower heat capacity. Suspended in the air—I expect it reached minus one-fifty, easy. Water condensed out on it. That’s all.”
“But I thought Mars was dry.”
“Yep, it’s pretty dry,” Ryan agreed. “But there’s still a little water in the atmosphere. More at lower altitudes. No surprise that it would condense on the rover.”
By the time they had winched it to the top of the cliff, the frost had sublimed away from the rockhopper. The frost bath had failed to clean it, though; it was still coated with a layer of yellowish dust.
They headed north and west. The ground they drove across was rocky, with a fine soil packing all the cracks and packed into the angles between rocks. Brandon saw Tana, driving the dirt-rover ahead, fighting to keep the dirt-rover under control on the smooth rock.
In the cabin of the rockhopper they still wore the chest-carapaces of their suits, but they all had their helmets and gloves off. It was beginning to smell rank, like the inside of a gym locker; they spent too much time in their suits.
Brandon clutched his fossil, rubbing the tips of his fingers over the smooth stone. Back at the bottom of the cliffs, Estrela had given him her rock hammer. Commander Ryan had complained that they didn’t have time to collect specimens, but if Ryan had found it himself, Brandon expected that he would have found the time. So while they had worked on setting up the winch, Brandon had carefully chipped it out of the rock to bring with them.
With his bare fingers, he could feel a lot more. It had fine, almost invisible ripples on the surface, like the pebbly skin of a lizard. It was relaxing to rub it.
Estrela was being quiet. She hadn’t been talking much since the accident, Brandon realized. She held her left arm awkwardly, bracing it with her right. He wondered if her arm still hurt.
“Hey, Estrela,” Brandon said. “How you doing?”
She turned to him. Her eyes had red rims, he suddenly noticed. His own eyes hurt just looking at her.
“Lousy.” Estrela’s voice was no louder than a whisper. “Go away. Leave me alone.”