He began to climb, the enclosure of the rock giving a welcome, if false, sense of security.

Every few feet, he glanced down between his legs, his view now obscured by the rock surrounding him, but he could still see that thing out in front, moving effortlessly between the second and third ledges up a section of the wall where Ethan had struggled.

Twenty feet up the crack, seventy above the canyon floor, his thighs burning.

Couldn’t tell how much farther he had to go to reach that piece of metal that had gotten him into the shit to begin with. On the other hand, if he’d been down in the canyon when those things had shown up, they’d be eating him right now. So maybe in retrospect that shimmering metal that prompted this ballsy climb had actually prolonged, if not saved, his life.

The monster reached the third ledge and, without a moment’s hesitation to rest or consider its next move, leaped off the narrow shelf of rock.

A single talon at the end of its left arm caught on a square millimeter of surface just inside the opening to the crack, and in a feat of brute strength, it pulled itself up with one arm and squeezed into the chute.

Ethan locked eyes with the monster as it began to climb on foot- and handholds so insignificant Ethan had disregarded them, traveling at least twice as fast as Ethan could manage.

Nothing to do but keep climbing.

He struggled up another five feet.

Ten.

The monster twenty-five feet away and close enough that Ethan could see the pink pounding of its massive heart, obscured through its skin as if tucked behind thick, frosted glass.

Ten more feet and then the crack appeared to lead out onto flat, vertical, horrifying wall.

The handholds near the top looked good, Ethan realizing that if he kept chimneying that thing was going to reach him before he made it out.

He switched to hand-over-hand climbing, racing up the last ten feet.

Just before the top, one of the holds broke loose and he nearly lost his balance.

Caught himself before he fell.

He could feel the wind streaming across the opening to the chute.

Glimpsed something catching sunlight straight above.

Froze.

Looked down.

He’d almost blown the chance to save himself.

With the monster fifteen feet away and two more trailing close behind it in the chute, Ethan reached down, the loose handhold that had nearly killed him just within reach.

He tore the chunk of rock from its housing, hoisted it over his head.

It was a handful, even bigger than he’d thought—two pounds of quartz-laced granite.

He wedged himself between the rock, took aim, and let it fly.

It struck the creature dead center of its face just as it was reaching for a new handhold.

Its grip failed.

It plunged down the chute.

Talons scraping rock.

Its velocity too great to self-arrest.

It hit the one beneath it at a high enough rate of speed to knock it from its perch, the pair crashing as one into the third, and then all three screaming for two long seconds as they shot out of the bottom of the chute, bounced off the third ledge, and accelerated toward the rocks below where they slammed aground in a tangle of badly bent appendages and broken skulls.

Ethan emerged out of the chute squinting against the flash of brilliance now just a few feet above his head.

He was at least a hundred feet above the canyon floor, and his stomach churned. From his new vantage point, he could now see that the opposite wall climbed another five or six hundred feet to a razor ridge, which in itself looked impassable.

If his wall did the same, he might as well jump off now, because he didn’t have it in him to climb another hundred feet, much less five.

The two remaining creatures on the wall snapped him out of the despair. Instead of following the others up the chute, they had climbed around, one on each side—slower going, but they were still alive and now thirty feet below Ethan.

He reached up and grabbed a ledge under the shiny metal, got both elbows onto the widest shelf of rock he’d seen, and hauled himself up, face-to-face with a steel vent protruding several inches out of the rock. It was square, approximately twenty-four inches across, the blades of a fan spinning counterclockwise directly behind it.

Talons clicked on the rock below.

Ethan gripped the sides of the vent, pulled.

It didn’t budge—it had been welded to the duct.

He stood up on the ledge and ran his hands over the surface of the wall until he came to what he was after—a large, twenty-pound wedge of granite that looked poised to fall.

He lifted it and smashed it down on top of the vent where it joined the duct.

The alloy disintegrated, the upper left-hand edge of the vent popping loose.

The creatures were ten feet below him now, so close he could smell the decay of their last kill wafting off them like some savage cologne.

He raised the rock again, brought it down in a crushing blow to the right-hand corner.

The vent snapped free and clanged down the cliff, bouncing off the rock and nearly striking one of the creatures on its descent.

All that stood between Ethan and the darkness of a ventilation shaft were the spinning blades of the air intake.

He rammed the rock into them and brought their revolutions to a halt.

Three hard blows completely detached the unit from its mount, Ethan reaching in, grabbing it by the blades, and slinging it over the cliff.

He picked up the rock, held it high, and dropped it on the closest creature as its talons reached for the ledge.

It fell screeching.

Its partner watched until it hit the ground, and then looked back at Ethan.

Ethan smiled, said, “You’re next.”

The thing studied him, its head tilting like it could understand or at least wanted to. It clung to the rock just below the ledge, within easy reach, Ethan waiting for it to make its move, but it held position.

Ethan spun around, searching the cliff wall within reach for another loose rock and coming up empty.

When he turned back, the monster was still perched on the wall.

Settling in.

Ethan wondered if he should climb on until he came across another sizeable rock.

Bad idea. You’d have to down-climb to get back to this ledge.

Ethan crouched, unlaced his left boot. Pulled it off, and then did the same with his right.

He held it—not nearly the heft of a rock, but perhaps it could do the job. Grasping it by the heel, he made a dramatic show of cocking back his arm as he stared down into the monster’s milky eyes.