Willow tightened her grip on my hand, but the tunnel became too narrow to walk side by side, and she had to fall behind me. I hated not being able to see her, but I wasn’t going to let her walk across any ground my weight hadn’t tested this far into the mine.

The air stirred from ahead, and Dad’s light bounced as he nodded. “See?” He pointed to the tunnel that appeared on our right as the path leveled out and widened into another large chamber. “This is an offshoot of one of the 1930s.”

“It’s not on any of the maps,” I said to myself as I took in the expansive tunnel and its sturdy beams. To the left were dozens of smaller chambers, some with wooden half walls, trimmed and topped with vertical iron bars and swinging doors made of the same, and some barren, left from exploratory blasts.

“I know it’s on at least one map,” Dad replied. “I just can’t remember where it is.” He touched his forehead. “I thought I gave it to you, but that can’t be right.”

Apprehension landed in my stomach like a brick. “Dad, are you okay?”

“Yeah. Of course. I’m fine.” But the lines in his forehead told me otherwise.

“How deep do you think we are?” Gideon asked.

“Sublevel three,” Dad declared, his headlamp illuminating the expanse of wall that was dotted with mined alcoves stretching as far as the light could reach on either side as the chamber narrowed to two tunnels that ran to either side. “Found a vein down here that wasn’t worth much, but something was better than nothing. But the miners needed air.”

His headlamp shone right, then left. Where the hell did we go from here?

“Them and me both,” Gideon said, walking past my dad and following the curve of the tunnel.

“Are you okay?” I asked Willow, noting that the rise and fall of her chest had increased.

“I just want to start screaming her name.”

“I’d hold off on that,” Gideon said, shining his light on a rubble pile in the back left of the chamber. “The entire thing is caved in over there.”

“Been like that for years,” Dad muttered. “Don’t just stand there—start looking. Don’t go moving rocks around or causing another cave-in.”

“Left or right?” Gideon asked.

My throat tightened.

“Doesn’t matter,” Dad stated, his headlamp swaying as he shook his head. “It’s a fifty-fifty shot. Pick one and start looking.”

“It matters,” I countered as Willow slipped her hand into mine.

“Split up but stay in this section,” Dad ordered. “We can search twice as fast.”

Left or right? There was no obvious choice as I looked both ways. It was a coin-flip dilemma.

“Left,” Willow said, her lamp shining on the barred chambers.

“You sure?” I asked.

“Left,” she repeated, quieter this time.