Naismith edges forward, the darkness broken only by the glow of his headlamp, one hand on the wall to his right. Sheets of slime mold squeak under his boots. Water trickles loudly through narrow channels in the rock.

Kepler's structure is riddled with canyons and caverns, still largely unexplored. All the geologists are desperately curious about them. He'll get a thesis out of this for sure.

Only it's a lot easier to make plans than it is to inch through narrow passages so deep that ground radar couldn't map them.

Especially when Naismith doesn't know what's making the scraping sounds behind him.

"We have no record of any fauna down here large enough to harm someone," he reassures himself, his voice thin in the wavering light.

The scraping gets louder. Skkkrrch-skrrch, it says, light and quick.

Skrrrrrch. Skrch.

Naismith pushes forward, but it's slower than he wants to, as though he's slogging through water. As though time is reluctant to pass.

Skkkkkrrrrrrrrrchhhhh.

The scraping sound is elongated, distorted—as if played back on a recording at half speed without pitch correction.

Naismith breaks into a painfully slow, shuffling run.

The narrow corridor widens abruptly just as an unseen rock catches his feet. Naismith trips, falls, smacks his head against the ground. He lifts his eyes and gazes into absolute blackness.

It's a long moment before he understands that something isn't wrong with his vision: his headlamp is broken. It's a much shorter moment before he realizes how badly he's screwed.

Naismith scrambles to his feet, reaching out blindly. No wall at his side to guide his way back. No light. No way to know where he is.

Behind him, drawing closer and closer, pitch deepening into the infinite like the drop of a continental shelf…

Skkkrchhhhhhhhhhhhh.

In the dark, Naismith screams.