“Not that I’m complaining,” he continued. “I’d be dead several times over if this place didn’t exist. The very first time I got stuck in the caves, of course. And now, we’d never be able to hide out here without it. With no hiding place, we’re all dead, right?”

He nudged me with his elbow, a conspiratorial gesture.

“Mighty convenient, how it’s laid out. Couldn’t have planned it much better if I’d sculpted it myself out of play dough.”

His laugh cleared a section of mist, and I saw the room for the first time.

Two rivers flowed through the dank, high-domed space. This was the chatter that filled my ears—the water gushing over and under the purple volcanic rock. Jeb spoke as if we were alone because we were.

It was really only one river and one small stream. The stream was closest; a shallow braided ribbon of silver in the light from above, coursing between low stone banks that it seemed constantly in danger of overrunning. A feminine, high-pitched murmur purred from its gentle ripples.

The male, bass gurgle came from the river, as did the thick clouds of vapor that rose from the gaping holes in the ground by the far wall. The river was black, submerged under the floor of the cavern, exposed by wide, round erosions along the length of the room. The holes looked dark and dangerous, the river barely visible as it rushed powerfully toward an invisible and unfathomable destination. The water seemed to simmer, such was the heat and steam it produced. The sound of it, too, was like that of boiling water.

From the ceiling hung a few long, narrow stalactites, dripping toward the stalagmites beneath each one. Three of them had met, forming thin black pillars between the two bodies of flowing water.

“Got to be careful in here,” Jeb said. “Quite a current in the hot spring. If you fall in, you’re gone. Happened once before.” He bowed his head at the memory, his face sober.

The swift black eddies of the subterranean river were suddenly horrible to me. I imagined being caught in their scalding current and shuddered.