“Maybe not,” he said.

“What do you mean?”

“See those quicksilver currents in the fog? I think they are emanating from a nearby source. This mountain is riddled with caves and tunnels, some natural, some human-engineered. Don’t know about you, but I’d rather spend the night inside a cavern than outdoors.”

Sierra watched him with a cautious expression. “What quicksilver currents?” She glanced around at the fog-choked woods. “This mist is infused with enough paranormal heat to make it glow but I don’t see any currents in it.”

North contemplated the stream of energy pouring through the fog. “There are two possibilities here. Either I’m hallucinating again or my talent is back in good working condition.”

“You’re not sure?”

“My senses feel normal again, but there’s one way to find out if that quicksilver energy stream is real. If I’m right, it’s powerful. You’ll probably be able to sense it if you get close to it. But we should maintain physical contact. Hold on to my belt.”

“Okay.” She reached under his leather jacket and took a grip on his belt. “For what it’s worth, I don’t think you’re hallucinating,” she said. “I took a look at your aura in the car mirror a couple of times on the way up here. You’re stable.”

Her faith in him fortified him as nothing else could have at that moment. He tightened his grip on the tuning machine and waded into the energy stream. The waves of quicksilver glowed like moonlight in the green fog. Sierra followed close behind.

She caught her breath. “I can’t see them, but I can definitely feel the currents now.”

“I’ve been told that the caverns and tunnels are the source of the paranormal energy in these mountains. Some of it is natural. Lucas Pine says that’s probably the reason the site was chosen as a location for one of the labs. But the heavy stuff is most likely the result of all the experiments and research that were done inside the caves. I’m betting that a strong river of heat like this indicates a nearby lab tunnel.”

“That sounds reasonable.”

“I can’t tell you how relieved I am to hear you say that.”

“Because it means I don’t think you’re unstable?”

“It’s the small things in a relationship.”

“Absolutely.”

The currents of the quicksilver energy got stronger and more intense. North discovered that it required an increasing amount of effort from all of his senses, normal and paranormal, to forge ahead.

“I feel like a salmon trying to swim upstream,” Sierra said.

“Bad analogy. Salmon that swim upriver usually come to a bad end.”

“Oh, right. The spawn-and-die thing.”

“That’s assuming they don’t get caught in a fishing net or eaten by a bear along the way.”

Night was coming on fast now. He knew that theoretically they could survive outside in the damp, disorienting fog, but it would be an ordeal. Olivia had warned them that people who got trapped in the mist tended to hallucinate. They got disoriented and they got lost, often permanently. North figured he’d had enough of ghostly visions.