I scramble on my hands and knees as Star pulls me deeper into the cave. My headlamp flashes around wildly, casting disorienting shadows through the tunnel and obscuring the others in front of me.

The drone of the vultures behind us fills the air with a sickening buzz. My hands and knees bang against hard, slippery rocks. When the top of my helmet slams against something above me, I duck down. The tunnel constricts around us, squeezing tighter and tighter.

I feel Star's grip on my arm release, but with just my headlamp I can hardly see what is going on ahead of me. I scoot along, practically on my stomach, to squeeze through as the tunnel gets narrower and narrower. My light flashes over the rough surface around us, illuminating the damp, reddish-pink mold covering the stones beneath my gloved hands.

Holding my breath, I squeeze through the tight passage like I'm swimming to the surface from somewhere deep underwater. The drone of the monsters chasing us rings through my ears, and the rocks and dirt constrict around me like the cave is closing in, preparing to swallow me whole. I feel like I'm crawling into the mouth of a serpent. I grit my teeth and pull myself along.

"Come on, Shawn," Star calls back to me as she crawls on ahead.

After shuffling a dozen steps on all fours, the space opens up on both sides and above me. I gasp in relief and push myself to my feet, but my back strikes the low ceiling before I can stand.

Buzzing and smacking echoes through the small entrance to the cave behind me. The swarm is closing in. Without missing a beat, I dive to my knees again, continuing to crawl behind the others. I whip my head around and glance over my shoulder. A ring of teeth barrels towards us, like a train through a tunnel, shining and flickering in the beam of my headlamp.

"Incoming!" I shriek.

With a thump, the monster collides into the face of the cliff. I brace myself as the entire cave shakes. Rubble and dirt tumble from above, coating me in a dusting of brownish pink.

The smacking sound intensifies, filling the entire tunnel with echoes. It's searching for us—seeing without eyes.

The worm's body pulses and writhes as it squirms through the small entrance. Its tentacles curl up along its side, pushing and thrusting its mass forward. When its wings reach the narrow part of the passage, they snap back. The joints contort so the wings lie flat against its body, allowing it to slink its way through. The maggots in its open mouth churn and gurgle like spaghetti in a blender.

"Oh my God! Oh my God!" I scream. My entire body shakes with fear.

"Don't stop, Shawn!" America yells from up ahead.

Grinding my teeth, I crawl behind the others. My ankle throbs each time my knee lands on the ground. It feels like the bones are sliding against each other, but I don't dare stop. The whacking and thrashing behind us pounds in my ears, driving me to keep moving.

Suddenly something wraps around my calf, like an octopus latching on to its prey. Pain explodes through my ankle. "Shit!" I scream. I roll over onto my back and kick my other foot at the huge tentacle squeezing my leg. "Get off!"

"Shawn!" Star shouts. The cave shakes around us—another one of the monsters colliding into the front of the cliff.

The grip on my ankle tightens as the tentacle snakes its way further up my calf, surrounding my knee. My headlamp flashes at it. The mouth consumes its entire face—a ring of chomping teeth with blood coated maggots twisting between them.

"I've got you!" Star yells. Her hand grabs me by the arm and pulls me back, but the monster yanks at my leg harder, and I'm tugged out of her grip and dragged a foot in the other direction—towards the monster.

"Help!" I scream. I throw my hands out and claw into the sides of the cave. I dig my gloved fingers into dirt as it drags me in. My right hand finally catches on a large rock. I struggle to grip it, my hand slipping over the smooth, mossy surface.

"Let me go!" I growl at it. I slam the heel of my free foot down on the tentacle as hard as I can. It squishes beneath me like a firm muscle. For a second, the pressure on my leg releases, and I tug it back. The suction cup-covered arm catches on the heel of my boot. I shake it frantically, finally, breaking free from the monster.

A hand grabs me and pulls me back, away from the monster. "Let's go!" Star shouts. Her eyes shine white as my headlamp reflects off them. The two of us rush down the tunnel. Ahead, Elias, Devin and America continue to squeeze their way along. America looks back at us over his shoulder, a grimace on his dirt-streaked face.

The cave shakes as another monster collides with the entrance. My breath catches in my throat, my pulse racing. I freeze where I am, bracing myself against the shower of stones and dirt. This one sounded bigger. Ahead of me, America crouches, covering his head to guard himself from the debris.

Another thump shakes the cave, even harder this time.

"Shit!" Star screams.

With a rumble, the ground beneath me releases like a landslide. I dig my fingers into the dirt to find a grip, but the rocks and stone slide out from under me like water slipping through my fingers. Gravity turns on its side, and my stomach drops to my feet.  Before I can process what's happening, I'm tumbling.

My side smacks against the ground, and I roll. The beam of my headlamp illuminates a tornado of spinning dirt and dust in front of me as I tumble. Pain shudders through my body each time I slam into the stony floor of the collapsing tunnel. Bracing myself with my elbows, I finally skid to a stop on my back. My ankle pounds, and my side stings and burns.

I pinch my eyes against the pain. My head spins. I'm too dizzy to move.

"What the fuck just happened?" Devin calls. The sound of his voice echoes around me. I can't place the source.

I blink. Beams of light flash around the cavern like police searchlights. Shaking, I push myself to my feet, resting all of my weight on my good leg.

As I get my bearings, I take in the scene. We're in a pit of some sort. The walls of dirt and stone slope up towards the rocky ceiling like the sides of a bowl.

America lies on the ground next to me, clasping his head and panting. Dirt and rubble sticks to a small, glistening bloody cut on the side of his cheek. A few yards away, Star helps Elias to his feet. Their space suites are now coated in dust and mold. Next to them, Devin crouches on his hands and knees, panting as he rubs his arm.

Something's missing.

The monster.

"Where did it go?" I gasp, my pulse rushing through my temples.

My eyes catch Star's for a second, but her gaze veers over my shoulder. She raises one shaking arm and points. "Behind you."

My heart skips a beat, and my hands clench into fists. I spin around, taking a step back from where she points.

When my headlamp lands on the monster, my jaw drops. Its ridged, earthworm-like body lies contorted in a mess of stones and rubble. Two long tentacles splay out next to it, still twitching with spasms like jolts of electricity are pulsing through them. The webbed wings fall in tangled heaps around it like a pair of broken umbrellas. Beneath a pile of large stones, its head has been crushed, leaving mushy black goo and dying maggots sprayed out across the pink dirt.

My stomach clenches, and I wretch. Luckily, it's been thirty-two years since I've eaten, so I don't have anything in my stomach to vomit up into my helmet.

"What about the rest of them?" I finally say. Sweat slicks my back, despite the fact that the air in this pit is frigid and damp. A chill rushes through me, and my good leg shakes uncontrollably. This creature might be dead, but if it could squeeze its fat ass through that tunnel, that means others could, too. They were banging against the cliff. It's only a matter of time until they get in, too. We have to find a place to hide.

I scan the area behind the monster, searching for the hole we fell through, but my headlamp only finds rocks and stone at the top of the slope. Plumes of dirt and dust dance in the beam of light like tiny flakes of pink snow.

Suddenly, a new fear creeps over me.

Where is the passage we came through? Did I get turned around when we fell? Did we come from the other direction?

I spin around, glancing behind the others frantically. "Which way did we come from?"

No one says anything.

"We got down here from somewhere," I say. I try to meet Devin's gaze, but he isn't paying me any attention. He just keeps rubbing his arm.

"Elias?" I ask. No response.

America finally raises his head, grimacing and shielding his face as the beam from my headlamp hits him in the eyes. "That is where we came from, Shawn," he says.

I swallow a lump in my throat, not sure if I'm relieved by his answer or horrified. "So . . . the tunnel fell in behind us?"

He nods.

"We're trapped down here?" My voice comes out quieter than I'd intended.

Silence.

"America?"

He doesn't say anything. Instead, he turns and spits something dark and red onto the ground. My stomach turns. I know it's blood.

"Look on the bright side, Shawn," Elias finally says. "At least this means those monsters are trapped up there."

We are all silent. The only sound is America's breathing and the respiration through the rest of our helmets echoing through the depths of the cavern.

"How far do you think we fell?" I whisper, finally breaking the silence. I listen for the sound of the monsters cawing or the pounding of their bodies against the cave, but there is no sign of it. "I can't even hear them anymore."

"Probably not as far as it felt," America replies.

"We need to get moving," Star cuts in. She paces away from us, down the sloping ground and towards the other end of the pit.

"What?" Devin asks. "Why? We're safe here."

"It looks like there is another tunnel over here." The dirt crunches under Star's feet as she reaches the back of the pit. She cocks her head, her light shining off and disappearing behind a turn in the walls. "There might be another way out of this cave."

"Are you fucking crazy?" Devin growls. "Those things are out there, and you want to find a way back up to the surface?"

"We're going to have to get out of here eventually." She crosses her arms over her chest. "And if there is another way out, that means there is another way in too."

"She's right," America pushes himself to his feet. He brushes some of the dust off his knees but gives up when he realizes he is absolutely coated in it. "If there is another way for those things to get in, we need to know about it. And not only that, this tunnel just collapsed under us. There might be another cave in soon, and I don't want us ending up under it."

Devin grimaces. "Fine," he finally says. He grips at his arm, hissing between his teeth. "Fuck."

"Is your arm okay, Devin?" Elias asks. "One of them bit you, didn't it?"

"My arm's fine," Devin growls. "It just itches a bit. Fucking thing took a good hunk out of me."

"Can I take a look?" Elias asks. "Check it out for you?"

"I said it's fine," Devin snaps. "Let's just get moving."

Elias hesitates for a moment, but finally he nods. "All right," he says. "But if it gets any worse, let us know."

Devin mimes a salute. "Will do, boss." Without another word, he turns on his heels and leads the way down the tunnel.

The fact that the path Star found goes down makes me uneasy. We want to reach the surface, not bury ourselves deeper beneath the planet. But, it's our only option right now. Other than stay here and wait for something else to find us first, we have no choice but to take it.