“We’ve all got lights,” Caleb said. He pulled an elastic band over his head and centered a light between his eyebrows. “Red or white, Mom?”

“Red for now,” Victoria said. “White after we’re outside.” The thought of the light hadn’t occurred to her. She pulled hers out of its assigned pocket in her rucksack and slipped it over her head, centering the light itself in the middle of her forehead.

The sky blinked white—like a distant lightning strike—and the Suburban died.

“Shit!” Copley cursed. “It’s gone. Steering, engine, everything.” He stood hard on the brakes to bring them to a stop.

“What just happened?” Luke asked.

“It’s begun,” McCrea said. “The first detonation.”

As he spoke, the sky lit up again. And again.

“We’ve gotta go,” he said. “First Sergeant, grab the gear out of the back.”

“Are we there?” Victoria asked.

“As close as we’re going to get,” McCrea explained as he pushed his door open. “We really need to move, folks.”

“Grab your stuff and let’s go,” Victoria said to the boys. Caleb opened the door on his side while Victoria opened hers.

Luke followed his brother. From the other side, she heard him yell, “What happened to the car?”

“EMP,” Copley explained. “Electromagnetic pulse. Nuclear explosions cause it, and they wipe out everything that has advanced circuitry.”

“But my headlight is still working,” Caleb said.

“No integrated circuitry,” Copley said. He was at the back of the Suburban with McCrea, pulling out their own gear.

The sky lit up again, this time with staccato flashes, five or six of them in rapid succession. A few seconds later, they heard what might have been thunder, and the ground trembled under their feet.

“We are out of time,” McCrea said. “First Sergeant Copley, you are the last to see a map. Lead on, please.”

Copley took off at a fast jog, heading up the road in the direction they were originally headed. Caleb was next in line, followed by his brother, while Victoria, then McCrea, brought up the rear. The terrain here was steep, probably every bit of 10 percent incline. Victoria didn’t think the boys would have difficulty keeping up, thanks to their soccer and lacrosse experience, but she’d have been lying if she said she wasn’t concerned about the burn she felt in her own legs.

“Don’t think about the pain,” McCrea said, as if reading her thoughts. “It’s not about the last step, it’s about the next one. Left, right, left, right. Pick ’em up and put ’em down.”

Three more flashes erupted in the sky—the brightest ones yet. Ten seconds later—maybe less—the pulse of a mostly spent pressure wave hit them with enough force to cause her to stagger-step to the side.

“Mom! They’re getting close!”

“Keep running!”