“God bless global warming,” he muttered, and laughed at his own wit.

People thought they were scared now? They thought they were terrified by Lear’s plague of madness? Wait until they saw their crops, their home, their car and its gas, their dogs and cats and cows and pigs, all chewed up, masticated by trillions of nanobots that did little but crap out more nanobots.

Wait until they realized how hopeless it was. How powerless they were. Wait until they saw the little sore on their ankle become a bleeding hole and endured the agony of being eaten alive, consumed, like a beetle being swarmed by fire ants. It would be like leprosy on fast forward. It would be like flesh-eating bacteria on meth.

Sure, maybe in places there would be pockets of a few scattered humans who would hold out for as long as six months. But it wouldn’t matter. The nanobots would eat the algae out of the sea and every oxygen-producing plant on the land and then, inexorably, the atmosphere itself would become fatal to life.

Dirt. Water. That would be planet Earth. Just dirt and water and a vast, inconceivably vast swarm of nanobots. Mindless. Without soul or sin. Efficient, relentless, unstoppable killers without malice, without meaning, without moral judgment. Without guilt—that most destructive, weakening, sickening, disabling of emotions.

Yes, his babies would obliterate without guilt.

He pulled up the picture he’d found of Lystra Reid and gave it the finger.

“Game, set, match, Lear. Death or madness? I got a little hint for you, sweetheart. The answer is death. Death, brought to you by Karl Burnofsky.”

Out in the lab he heard a disturbance: raised voices, a bustling movement, chairs scuffling. The door to his office was locked. He drew the pistol.

Someone banged hard on his door: a cop’s knock.

“Damn,” he said. “I’d have liked to hit a billion first.”

“Burnofsky! Come out here. The bosses want you.”

“I’m busy,” Burnofsky yelled.

“Don’t think they care, Dr. B. You’ve got about ten seconds.”

The Twins wanted him, did they? Well, why not? It would be worth a laugh. And he had something special for them, just for them, something ever so special.

“Give me a second!” he yelled. In his desk, all the way at the back, he found the little vial he’d prepared against this very moment. He slipped it into his pocket along with the remote control that could unleash Armageddon and opened the office door for what he suspected would be the last time.

The area within the force field continued to fill with his children.

Keats had his biot back on Caligula’s optic nerve. He was again seeing what the killer saw. Caligula seemed to be sitting, perhaps with his back against a wall. His legs were stretched out before him. He stared at his missing fingers, bleeding freely, unbandaged. He leaned down to rub a spot of mud from his boot, glanced at the timer—six minutes and nine seconds—then apparently coughed as his head jerked violently and his hand came up to his mouth.

Just six minutes until the natural gas flooding the basement would achieve sufficient density that a spark would bring down the entire building. The gas was invisible dynamite being stacked, ton upon ton. Caligula’s eye glanced toward the ruptured pipe. He had a picture of something in his hand, a photograph of a serious little girl slumped in a busted-webbing lawn chair outside a shabby trailer. There was a Ferris wheel in the background.

Caligula coughed again and drew something out of his bag. Keats saw a small steel cylinder, a clear plastic hose smeared with Caligula’s blood, and a clear plastic mask with elastic straps. It reminded him of the lecture aboard an airplane: Should there be a sudden loss of cabin pressure … Caligula pulled the mask on, and now the plastic partly filled Keats’s view. Caligula was determined to wait out the—

No, he was up, up and staggering, but not toward the rupture, or toward the elevators. Keats saw a steel door. Caligula’s eye went to the handle, then his hand as it touched the metal of the door.

“He knows your guys are burning through,” Keats said dully.

“Jindal!” Charles yelled in response.

Jindal talked into his phone and reported, “They say they’ll be through any second.”

Caligula glanced back toward the bomb. Glanced at the gun in his hands. Suddenly they trembled. He seemed to be struggling to hold on to the weapon; his mutilated hand was still bleeding freely, but even the fingers on his good hand looked stiff, uncooperative.

The gun fell from his grip. The picture, too, was facedown on the floor.

“He’s having a stroke,” Keats reported. Go on, he told himself, just keep watching. Until the end. Be the good boy. No freaking out, no last-minute pleas. Tough, that’s how his brother Alex had always been. “He’s stroking out from the artery I cut.”

Sadie was looking at him, her eyes ashamed, horrified.

“Not your fault,” he said to her. “None of this is your fault.”

“But it is,” she said.

“He’s picked up a crowbar. His fingers can barely hold it. He’s dropped it. He’s staring at it.”

“For God’s sake, evacuate the building!” Plath shrieked at the Twins.

Burnofsky, disheveled but animated, came in with guards on either side. His rheumy eyes sparkled. “Ah, ah, ah!” he said on spying Plath and Keats and Wilkes. “So, that’s the panic.” He seemed pleased and relieved.

“Help me get these idiots to evacuate the building,” Plath pleaded. “Caligula’s flooding the basement with natural gas. In six minutes this whole place goes up!”