Page 2 of River Dragon’s Song

“I know.”

“I just wish you’d believe the rest of us are good at it too.”

He didn’t wait for an answer, which was probably just as well because she didn’t have one. She watched his light move away down the tube until it merged with the others, three small glowing points in the blackness, and then she was alone.

The silence settled around her as soon as their footsteps faded. It wasn’t a true silence. Lava tubes were never completely quiet. There was always the faint hiss of air moving through the cracks, the tiny click of cooling stone, the soft rasp of her breathing through the mask. But without the others’ voices in her ear, the dark seemed a great deal larger.

She took a deep breath of the thin, metallic air from her mask and got to work. She liked this part more than she wanted to admit. There was something soothing about working her way along a wall with a lamp and a hammer, testing each anchor in turn. She carefully marked the questionable ones with a stripe of bright yellow paint and replaced the ones that were actually failing. The rock always told the truth if she listened to it long enough. People were a lot harder to read.

Marker twelve came out easily, far too easily, and she frowned at the fine crumbled stone clinging to the threads. The basalt around the hole wasn’t cracked. It was rotten, pitted with tiny holes like a sponge, and when she pressed her glove against it, a thin crust flaked away and drifted slowly to the floor in the low gravity.

“That’s not right,” she murmured.

She set a new anchor two hands’ width to the left, in rock that rang properly when she struck it, and moved on to the next one. That one was fine. So was the next. But when she reached marker fifteen she found the same honeycombed stone around the bolt, and the rock face beneath it was damp.

Frankie stopped.

She slowly brushed her fingertips over the stone. Her gloves were too thick to feel much, but the lamp showed a faint dark sheen that had nothing to do with the natural gloss of the basalt. When she pulled her hand away, the fingertips of the glove were darker too.

Water. Her breath caught as she stared at it. It wasn’t impossible, exactly. Everybody knew there was ice beneath the surface of Mars. The settlements drilled for it, melted it and pumped it through their domes and greenhouses, and every homesteader on the planet had a water drill somewhere on their claim. But the ice was frozen solid. Down here, where the temperature never changed and the sun never reached, it should have been as hard as the rock around it. Liquid water didn’t just seep out of a lava tube.

She checked the thermometer on her wrist unit and frowned. The reading was several degrees warmer than it had been at the base of the access shaft. Not warm enough to matter to anyone who wasn’t paying attention. But she was paying attention.

“Ethan,” she said. “Can you hear me?”

A burst of static answered, and then his voice, faint and broken. “…at the… chamber. Tanjiri’s… readings are…”

“There’s moisture in the wall at marker fifteen. Liquid moisture. And the temperature’s rising.”

More static. She thought she heard him say something about the relay, and then nothing at all.

She tapped the side of her helmet as if that would help and immediately felt ridiculous. The comms had been patchy all day. Lucas had grumbled about the iron content in the basalt interfering with the signal and had promised to put in another relay once they reached the lower chamber. They were probably just out of range. She would finish the section, catch up with them, and tell Ethan in person. He could roll his eyes at her in person too.

She had turned back to the wall when she felt a soft touch of air across her cheek, just above her mask, and lifted her face into it without thinking. The air in a lava tube moved, but it moved in predictable ways, sighing in and out of the cracks as the pressure on the surface changed. This was different. It came from somewhere to her left, from a low opening in the side of the tube. She had marked it yesterday as too small and too unstable to explore. And it was warm, not just warm for Mars but truly warm.

She crouched down in front of the opening and shone her lamp inside. The side passage was little more than a crack at first, barely wide enough for her shoulders, but it opened out a few meters in and sloped steeply downwards. The rock on either side was dark and glistening, and the warm air flowed steadily past her face, carrying a faint scent she couldn’t place. It wasn’t the usual dull metallic tang of dust and stone. It smelled almost green.

And beneath the hiss of the air, so faint that at first she thought she was imagining it, she heard something else.

Running water.

She held her breath and listened. The sound didn’t go away. It was a soft, constant murmur she hadn’t heard since she left Earth. It was coming from somewhere below her, deep in the dark at the bottom of the passage.

Except that there was no running water on Mars.

Just an auditory anomaly, she told herself. Something to do with the way the air flowed through the chambers below.

She knew exactly what she should do. She should mark the opening, finish her section, and go and get the others. She should write it up in her report with every measurement and every reading. And she should let GenCon decide whether it was worth risking anyone’s neck to find out what was down there. That was the procedure. That was what she told every construction crew on every job site, usually while they were rolling their eyes at her.

But the others were fifty meters ahead in the lower chamber, too excited about Tanjiri’s anomaly to answer their comms. By the time she dragged them back here, Ethan would have decided it was a leaking ice seam. Tanjiri would be halfway down the passage without a safety line. And this time, Frankie wanted to see it first. Just a look. Just a few meters, enough to be sure she wasn’t imagining it.

She hummed under her breath as she set an anchor at the mouth of the passage, a tuneless little habit she’d never quite managed to break. Her mother used to tease her that she sang to her homework. Her training instructors hadn’t been nearly as amused. She clipped a line to the anchor and then to her harness, tugged it twice, and tested the rock around the bolt with her hammer until it rang clean.

“Ethan, I’m checking a side passage near marker fifteen,” she said into the mic, in case any of it got through. “There’s a warm draft and what sounds like water. I’m on a line. I’ll be ten minutes.”

Static hissed in her ear.

“I’ll take that as a yes.”