But the girl made no move to leave. She appeared to be waiting for something. She glanced around, her eyes pulled into a squint, as if noticing for the first time that the bus was empty, a ruin. Then she rose, drawing her pack onto her shoulders, and climbed out through the window.

The bunker was just where Hollis had promised.

He led them to a spot where the third mountain stood between the other two, turned east again, and in half a click he stopped. “This is it,” he announced.

They were facing a wall of rock. Behind them, the setting sun cut a final sliver of light across the horizon.

“I don’t see anything,” Alicia said.

“You’re not supposed to.”

Hollis slung his rifle and began to scramble up the wall. Peter watched him with a hand over his eyes against the reflected glare. Ten meters up he disappeared.

“Where did he go?” Michael said.

The face of the mountain began to move. A pair of doors, Peter realized, made to blend with the surface as camouflage: they backed into the face of the hillside, revealing a dark cavern and the figure of Hollis standing before them.

It took Peter a moment to absorb the full dimensions of what he was seeing: a vast vault, carved from the mountain itself. Rows of shelving extended into its dark recesses, stacked with pallets of crates that reached high above their heads. A forklift was parked near the entrance, where Hollis had opened a metal panel in the wall. As the group moved inside, he flipped a switch and the room suddenly thrummed with light, issuing from a network of glowing ropes on the walls and ceiling. Peter heard the airy hum of mechanical ventilation coming on.

“Hollis, these are fiber optics,” Michael said, his voice lit with amazement. “What’s the power source?”

Hollis flipped a second switch. A yellow warning beacon sprang to life, swiveling with a mad urgency over the doors. With a clunk of gears engaging, the doors began to slide from their pockets, dragging blades of shadow across the floor.

“You can’t see them the way we came,” Hollis explained, lifting his voice over the racket, “but there’s a solar array on the south face of the mountain. That’s how Demo found the place.”

A hard bang as the doors closed, the echo ricocheting deep within. They were sealed away now, in safety.

“The stack won’t hold much of a charge anymore, but you can run straight off the panels for a few hours. There are some portable generators too. There’s a fuel depot just a short walk north of here. Gas, diesel, kerosene. If you bleed it off right it’s still usable. There’s more than we could ever use.”