A scraping and thumping in the passage breaks the silence. Anders sighs and drops my hand.

“Hello, Eric. Were we gone five seconds longer than anticipated?”

“More like five minutes.” Dalton’s headlamp floods the cavern with light as we flick ours on.

“God forbid,” Anders mutters.

“I got worried.”

“That what? We’d been devoured by cave bears?”

“We need to get back before dark, and Petra still wants to show Casey something.”

Another deep sigh, and Anders moves into the lead. As he passes Dalton, he murmurs, “Thanks, boss. I was worried. Those cave bears, you know. Dangerous and unpredictable.”

Dalton grunts and motions for me to follow Anders out.

What Petra wants to show me is a chute leading off a huge cavern known as the Cathedral.

“It seems too tight for the guys, so they won’t risk it,” she says. “I fit, but you know Eric—either we stay within sight or we need a buddy.”

“Cave bears,” Anders says.

“Basic safety,” Dalton says. He turns to me. “If you want to try the chute, go ahead. If Petra fits, you definitely will.”

“Thanks,” Petra says.

He ignores her. “But it’s up to you. As always.”

I stick my head into the chute. It’s called that because it goes, well, down. Like a laundry chute. I can’t even see what’s at the bottom.

“It looks like a small cavern,” Petra says. “With branching passages. We won’t go far, but it would be nice to map a little more.”

When I put my head in farther, my chest constricts, as if I can feel the walls pressing in. It looks impossible to fit through. But while Dalton may have been a little impolitic in pointing it out, Petra is bigger than me. Bigger bust. Bigger hips. If she can get through, I can.

“Let’s do it,” I say.

She lets out a whoop and taunts the guys. Then she goes through, headfirst. I wait until she calls, “In!” and then it’s my turn. Mick crouches and gives me a few tips for the tighter passages. He’s barely said a full sentence during the trip—he’s not exactly a chatty guy—but he takes the time to be helpful, and I appreciate that.

The first section is easy. Then the chute angles slightly, and this is the “squeeze”—the part that keeps the guys out. I wriggle my head and shoulders through. Then my hips get stuck and my breathing picks up, as I see that now-familiar image of me trapped forever in a chute. I can hear Mick’s voice, as if he’s whispering in my ear.

If Petra got through, so can you. Once your shoulders make it, the rest is fine. Relax and wriggle and be patient. Back out if you have to, but remember that’ll be harder than going straight on.

I’m finally through. It may be a chute, but it has enough of an angle that I don’t tumble out headfirst. When I see the end coming, I put out my arms, and it’s like sliding into home base. Very, very slowly sliding … as I propel myself with my knees and feet and hips. Apparently this looks hilarious. Or so Petra’s peals of laughter suggest as I finally touch down.

“You make it look so much tougher than it is, Casey,” she says as I get up. “I really wish I had my sketch pad.”

“Yeah, yeah.” I brush off my knees. Which is a mistake, because I definitely have sliced one open and I only rub dirt into the cut.

I look up to see I’m crouched in a small cavern.

“Check this out,” Petra says, waving her headlamp at an alcove to the side. Inside, there are what I’ve come to know as soda straws—baby stalactites.

“Ten minutes,” Dalton calls down the chute. “I’m timing it.”

“I forgot my watch,” I call back. “If we’re late, just come down and get us.”

Petra snickers. Dalton says something I don’t catch. I won’t give him grief. I check my watch—yes, I’m wearing it—and make a mental note of our deadline.

“Which way first?” I ask Petra.

There are three options. She bends to check the narrowest and declares it too narrow. I move to the biggest of the three. It’s almost a straight drop, but wide enough to go feet first. When I shine my headlamp down, I can see the bottom, less than ten feet below, and the walls are rough and angled enough to climb back up.

“Can I go first?” I ask.

She grins. “Getting into the explorer spirit?”

“I am. Also, I’m the one with the gun because, you know, cave bears.”

“Of course. The chute is yours. Virgin territory awaits.”

I slide down. The wider passage actually makes it a little tougher, because I can’t just leap down the chute or I’d bang myself all to hell. I use my arms and legs as braces and find foot- and handholds and slowly lower myself until I’m in the cavern. Then I drop the last few feet.

The cavern ceiling is only about three feet off the ground. Which means I have to wriggle down until I’m crouching. My helmet finally comes out of the chute and my light shines on …

An arm.

I’m staring at a human arm.

There’s a moment where my brain says no. Just no. In the past two weeks, I’ve seen severed legs, a skull, and an intestine nailed to a tree. This just isn’t possible. It’s too much. I must be seeing a weirdly-shaped stone or a bleached-out branch, and after so many damn body parts, I mistake it for an arm.

But that’s not the answer. I wish it was. God, I really fucking wish it was, because when I see that arm—the light-brown skin, the slim fingers, the nails with chipping purple polish … I know who it is: the girl who celebrated her twenty-first birthday two months ago. Who went missing a few days later.