Page 6

Nothing happened.

“Oh, no. No, no, no. Don’t you dare.”

She pulled off her helmet and turned it over in her hands, running her fingers along the housing by touch. The lamp was still attached, but when she tilted it towards the faint blue light she could see a jagged crack across the lens. Water had seeped in behind it. She shook the helmet gently and heard a tiny, hopeless slosh.

She took a deep breath and then another. She had worked on job sites for eight years. She had fixed equipment in dust storms and in dark mine shafts. Once, memorably, she had fixed it in the back of a moving rover while the driver took corners like he was trying to kill them both. A cracked lamp was not going to beat her.

She pried the lens loose with her thumbnail and tipped the water out. She wiped the inside of the housing as dry as she could with the cuff of her coveralls. Then she dug hopefully through the pockets on her harness until she found the roll of repair tape she always carried. Ethan had laughed at the tape on the first day of the survey. He had asked if she was planning to fix the entire lava tube with it.

“Guess who’s laughing now,” she muttered, and wrapped a careful strip around the cracked lens to hold it together.

She pressed the switch again. The lamp flickered once, twice, and then steadied into a weak but beautiful white beam.

She laughed out loud, a shaky sound that echoed back to her from the darkness, and immediately regretted it when her side twinged. She put her helmet back on anyway, grinning like a fool beneath her mask, and turned her head slowly to look around.

Wow. The light swept across the cavern. It didn’t reach far, but it didn’t need to. Even the small circle it cast was enough to make her breath catch in her throat.

She was sitting on a long bar of dark gravel at the edge of a wide, churning pool. Behind the pool, a curtain of water poured down out of the darkness overhead and crashed into the surface in a thick white column, throwing up a fine, cold spray that drifted across her face. At the far end of the pool, the water ran away into the dark in a broad, fast stream, rippling over the stones and disappearing around a bend in the rock. Everywhere she looked, the walls were covered with patches of the same soft blue glow she had seen on the ledge above. In some places long, pale strands that looked almost like vines hung down from cracks in the stone.

It hadn’t been a dream, then. She had half-believed that it would be.

She climbed stiffly to her feet and limped down to the edge of the pool. She crouched and put her hand in the water, and for a long moment she just watched it run over her glove.

Liquid water didn’t exist on Mars. Not naturally. Not flowing freely through a cavern in the dark as if it had every right to be there. But this water was flowing. It was cold, and it was moving, and it was real.

She checked the thermometer on her wrist unit and frowned at the numbers. It was warmer than it had been in the lava tube, warmer than the surface would be at night. But it was barely warm enough for liquid water. And yet here was a river of it, pouring out of the dark.

If the water was liquid, there was a reason for it. Something was heating it. Geothermal activity, maybe, or pressure from the rock above. There had to be a rational explanation. She just didn’t know what it was yet.

She pulled a sample vial from her kit, filled it, and sealed it carefully. Then, because she was curious and because she wasn’t sure how much longer the kit would last, she ran a quick test on another few drops.

The results made her sit back on her heels. It was clean. Mineral-heavy, a little high in iron and sulfur, but clean.

“Well,” she said out loud. “That’s one problem solved.”

Then she assessed the rest of her situation. She made herself do it properly, the way she would have on any other job site. She started with an inventory, emptying her emergency pack onto a level stretch of gravel above the waterline. She set everything out in a neat row where she could see it. One thermal blanket, silver and crinkly and folded into a square the size of her palm. A small first-aid kit. A folding multi-tool, a coil of thin cord, two emergency flares and her sample kit. Her locator beacon. The spare battery pack for her helmet lamp.

And six protein bars, two of them the terrible peanut-flavored kind that nobody liked. She lined the bars up last and looked at them for a long time.

The water would keep her alive for a while. The mask would too, but her full-face mask was still packed neatly in the equipment case back in the lava tube. She was wearing the ordinary kind, the same small nose mask every settler on Mars wore when they stepped outside a dome. It would go on filtering the thin air and concentrating what little oxygen there was for as long as she needed it. But it had been designed for walking from one building to another, not for extensive physical exertion.

When she had tried to hurry along the gravel bar earlier, her head had started to swim after a few dozen steps. She’d had to stop and lean against the wall until the black spots cleared from her eyes. That meant she would have to take everything slowly.

And six protein bars weren’t going to last long. She did the arithmetic in her head, because she couldn’t not do it, and then did it again because she didn’t like the answer the first time. If she ate half a bar twice a day, she had six days before she ran out. The battery for her lamp would give out sooner than that, unless she spent most of her time sitting in the dark.

Her wrist unit showed an oxygen reading for the cavern air, and she frowned at that too. It was higher than on the surface. Not by much, and nowhere near enough to breathe without the mask, but higher. It didn’t make any sense. None of this made any sense.

“Six days,” she said quietly. “Okay. People have done a lot with six days.”

She picked up the beacon next. It was a small, sturdy block of GenCon-issue plastic, supposedly designed to send a signal through half a kilometer of solid rock. She had tested it herself at the start of the survey and it had worked perfectly, which was more than she could say for most of the equipment GenCon issued to its field staff.

She turned it on, and the little green light blinked obediently. The display screen searched and searched and finally flashed a single discouraging message at her.

No signal.

She stood up and walked slowly along the gravel bar, holding the beacon over her head like an offering. She tried the far end of the bar, then the edge of the pool, then a narrow ledge beside the falls where she had to press her back against the wet rock and hold her breath. The green light kept blinking. The screen kept saying the same thing.

She had no idea how far she had fallen. She remembered the ledge, and the long drop, and then nothing but water. The cavern above her was so high that her lamp couldn’t find the ceiling. If she was within half a kilometer of the surface, the beacon should have been able to reach someone. If she was deeper than that, or if there was too much iron in the rock between her and the surface, it might as well have been a paperweight.