A door opened, and then another one. The others seemed to be as sickened as he was, but they came into the hallway. He saw that the first one was Ortega. He was carrying a rifle, probably one of the rifles that Duquesne had brought here. The next two had pistols. Duquesne said, “We’ve got to get air in here.” Then he looked around. “Where’s—” He couldn’t remember the name of the man who was missing. “Bysantski!” he shouted. “Matt! Get up!”

He had noticed that after a time standing, he felt better, and the others seemed to be reviving a little too. The gas, whatever it was, must be heavier than air, lingering thickest near the floor. “Come on. We’ve got to get outside.”

He staggered toward the front door.

“Wait!” shouted Ortega. He pushed Duquesne aside and stepped to one of the narrow windows that looked like gun ports, lifted the latch, and pulled the window inward.

“What are you doing?” It was Bysantski’s voice. Had he been up all along?

Ortega had his eye to the window.

“That’s not enough air. We’ve got to go out,” said Bysantski.

Ortega ignored him. He stepped back a pace so the rifle muzzle wouldn’t protrude out the window. “I’m going to fire off a few rounds. If they’re out there, they’ll fire back. If they don’t, we’ll know it’s safe.”

In the very dim light Paul Duquesne saw Ortega’s finger move into the trigger guard and begin to pull back. “Don’t!”

The round fired and the muzzle flash ignited the propane gas that had filled the concrete house.

From beside the water tank, Leah saw all the narrow glass windows blown outward at once. Cracks appeared in the concrete walls, but they were so heavily built that most of the force of the blast burst upward through the roof. Wooden beams jutted up over the walls, and terra-cotta roof tiles shattered and flew everywhere. The plywood sheets beneath the tile layer were blown apart, and flames from the inside billowed upward into the night sky.

After about ten seconds, the rounds of ammunition hoarded in the house began to cook off and fire in all directions, most of them pounding against the concrete walls and caroming everywhere until their energy was expended.

Leah dropped to her stomach and aimed her rifle at the back door. The door was shut. She waited for it to open. She waited a full minute, then another, then got up and backed away.