The door opened. His escort waved him forward, stepping aside and allowing Painter to pass. Once he was through, the door closed behind him.

The room was paneled in dark mahogany and smelled vaguely of pipe tobacco. A matching mahogany desk stood in the center. Behind it, Tony “The Tiger” Rector rose to shake his hand. He was a large man, not fat, but someone who had once been well muscled now gone a little soft as he crossed his sixtieth year. But flesh was all that was soft about the man. His eyes were blue diamonds, his hair slicked and silver. His grip was iron as he shook Painter’s hand and nodded him to one of the two leather chairs.

“Have a seat. I’ve called up Dr. McKnight. He’ll be joining us.”

Dr. Sean McKnight was Sigma’s founder and director, Painter’s immediate superior, an ex–Navy SEAL who had gone on to earn a Ph.D. in both physics and information technology. If Dr. McKnight was being called in, then all the big boys were coming to play. Whatever was going down was significant.

“May I ask what this is in regard to, sir?”

The admiral settled into his own chair. “I heard about the bit of unpleasantness up in Connecticut,” he said, sidestepping the question. “The boys down in the Advanced Technology Office are waiting for that spy’s suitcase computer to be delivered. Hopefully, we’ll be able to retrieve the plasma weapons data from it.”

“I’m sorry we—I failed to obtain the password.”

Admiral Rector shrugged. “At least the Chinese won’t be getting their hands on it. And considering all you faced, you did a fine job up there.”

Painter held back asking about his former partner. Cassandra was most likely heading to a secure site to be interrogated. From there, who knew? Guantánamo Bay, Fort Leavenworth, or some other military prison? It was no longer his concern. Still, an ache throbbed in his chest. He hoped it was only indigestion. He certainly had no reason to feel any pangs over Cassandra’s fate.

“As to your question,” the admiral continued, drawing him back to the moment, “something was brought to our attention by the Defense Sciences Office. There was an explosion over at the British Museum last night.”

Painter nodded, having listened to the news on CNN on the way here. “Lightning strike.”

“So it’s been reported.”

Painter heard the denial and sat straighter. Before he could inquire, the door opened. Dr. Sean McKnight strode into the room, a gale barely suppressed. His face was red, his brow damp, like he’d run all the way here.

“It’s been confirmed,” he said quickly to the admiral.

Admiral Rector nodded. “Take a seat, then. We don’t have much time.”

As his boss sat in the remaining leather chair, Painter glanced over. McKnight had worked with DARPA for twenty-two years, including a stint as the director of its Special Projects Office. One of his first “special projects” had been the formation of Sigma Force. He had envisioned a team of operatives who were both technologically savvy and militarily trained—“brains and brawn,” as he liked to say—who could operate with surgical precision to secure and protect classified technologies.

Sigma Force was the result.

Painter had been one of the first recruits, handpicked by McKnight after Painter had sustained a broken leg during a mission in Iraq. While he had been recuperating, McKnight had taught him the value of honing his mind as well as his body, putting him through an academic boot camp that was tougher than his BUDS training to become a Navy SEAL. There was no person on the planet whom Painter held in higher esteem.

And now to see him so shaken…

McKnight sat near the edge of his seat, back straight. It looked like he had slept in the charcoal suit he wore, appearing all his fifty-five years at the moment: his eyes crinkled with worry, lips tight, sandy gray hair uncombed.

Something was clearly wrong.

Admiral Rector swiveled a plasma monitor on his desk toward Painter. “Commander Crowe, you should view this footage first.”

Painter shifted closer, ready for some answers. The screen’s desktop filled with a black-and-white video.

“This is the security surveillance for the British Museum.”

He sat silently as the video rolled. A guard appeared on the screen, entering a museum gallery. It didn’t take long. As the explosion ended the tape, whiting out the screen, Painter sat back. His two superiors studied him.

“That luminous sphere,” he said slowly. “That was ball lightning, if I’m not mistaken.”

“Indeed,” Admiral Rector confirmed. “It was the same assessment that drew the attention of a pair of researchers with the Defense Sciences Office who were in London. Ball lightning has never been caught on film.”

“Or been that destructive,” Dr. McKnight added.

Painter recalled a lecture he’d heard during his Sigma Force training in electrical engineering. Ball lightning had been reported from the times of the early Greeks, seen by groups of people and reported in many places. Its rarity had kept it a mystery. Theories for its formation varied from free-floating plasma caused by the ionization of air during thunderstorms to the vaporization of silicon dioxide from the soil after lightning struck the ground.

“So what happened at the British Museum?” he asked.

“This.” Admiral Rector had removed an object from a desk drawer and placed it on his blotter. It looked like a blackened piece of rock, about the size of a softball. “We had it shipped on a military jet this morning.”

“What is it?”

The admiral nodded for him to pick it up. He did and found the object unusually heavy. Not rock. It felt dense enough to be lead.

“Meteoric iron,” Dr. McKnight explained. “A sample from the artifact that you saw explode a moment ago.”

Painter placed the chunk back on the desk. “I don’t understand. Are you saying the meteor caused the explosion? Not the ball lightning.”

“Yes and no,” McKnight answered cryptically.

“What do you know of the Tunguska explosion in Russia?” Rector asked.

The sudden shift in subject caught Painter off guard. His brow furrowed as he dredged up old history. “Not much. Something about a meteor strike, back in 1908, somewhere up in Siberia, caused a big blast.”

Rector leaned back. “ ‘Big’ is a bit of an understatement. The explosion uprooted a forest for forty miles around, over an area about half the size of Rhode Island. The blast liberated the energy equivalent of two thousand atomic bombs. Horses were knocked over four hundred miles away. Big just doesn’t quite cover the extent of the explosion.”

“There were other effects, too,” McKnight said. “A magnetic storm created a vortex for six hundred miles all around. For days afterward, the night skies were luminescent from the amount of dust, bright enough to read a newspaper by. An EM pulse wrapped itself halfway around the world.”

“Christ,” Painter mumbled.

“Those who witnessed the blast from hundreds of miles away reported seeing a streaking bright light in the sky, as brilliant as the sun, trailing a tail of iridescent colors.”

“The meteor,” Painter said.

Admiral Rector shook his head. “That was one theory. A stony asteroid or comet. But there are several problems with that theory. First, no meteor fragments have ever been found. Not even any telltale iridium dust.”

“Carbonaceous meteors usually leave an iridium fingerprint,” McKnight said. “But such a finding was never unearthed in Tunguska.”

“And there was no crater,” the admiral added.

McKnight nodded. “The force of the blast was forty megatons. Prior to that, the last meteor to even come close to such force struck Arizona some fifty thousand years ago. And it was only three megatons, a mere fraction of Tunguska, and it left a massive crater a mile wide and five hundred feet deep. So why no crater, especially when we so clearly know the epicenter of the blast due to the radial felling of the trees outward from ground zero?”

Painter had no answer to this…or to the more immediate question in his mind: What did any of this have to do with the British Museum?

McKnight continued. “Since the time of the explosion, there have also been interesting biological consequences noted in the region: an accelerated growth of certain ferns, an increase in the rate of mutations, including genetic abnormalities in the seeds and needles of pine trees and even ant populations. And humans have not escaped the effect. The local Evenk tribes in the area demonstrate abnormalities in their Rh blood factors. All clear indications of some radiological exposure, most likely gamma in origin.”

Painter tried to wrap his mind around a craterless explosion, unusual atmospheric effects, and residual gamma radiation. “So what caused all this?”

Admiral Rector answered, “Something quite small. About seven pounds.”

“That’s impossible,” he blurted.

The admiral shrugged. “If it was ordinary matter…”

The mystery hung in the air for a long moment.

Dr. McKnight finally spoke. “Newest research as of 1995 suggests that what struck Tunguska was indeed a meteor—but one composed of antimatter.”

Painter’s eyes widened. “Antimatter?”

He now understood why he had been called into this briefing. While most folks considered antimatter to be the realm of science fiction, it had become reality in the past decade with the production of antimatter particles in laboratories. Leading the forefront in this research was CERN Laboratories in Geneva, Switzerland. The lab had been producing antimatter for close to two decades using a subterranean Low Energy Antiproton Ring. But to date, an entire year’s production of antiprotons by CERN would produce only enough energy to flicker a lightbulb for a few moments.

Still, antimatter was intriguing. A single gram of antimatter would produce the energy equivalent of an atomic bomb. Of course, someone would first have to discover a cheap, readily available source of antimatter. And that was impossible.