Stepping into the sunlight, he trekked across the court toward the southeast arcade. The façade above the keel-shaped arches featured a series of ornate roundels and niches cut into the stucco, which he noticed had become favored roosting spots for some local pigeons. He walked toward a protruding central arch topped by a high rectangular panel, which signified the entrance to the prayer hall.

The call to midday salat , or prayer, had occurred nearly an hour earlier, leaving the expansive prayer hall nearly empty. Outside the foyer, a small group of students sat cross-legged on the ground, listening to a university instructor lecture on the Qur’an. Skirting around the group, the man approached the hall entry. There he met a bearded man in a white robe, who eyed him sternly. The visitor removed his shoes and quietly offered a blessing to Muhammad, then proceeded in with a nod from the doorman.

The prayer hall was an open expanse of red carpet punctuated by dozens of alabaster pillars that rose to a beamed ceiling. As in most mosques, there were no pews or ornate altars to provide orientation. Cupola-shaped patterns in the carpet, outlying individual positions of prayer, pointed toward the head of the hall. Noting that the bearded doorman no longer paid him any attention, the man made his way quickly along the pillars.

Approaching several men kneeling in prayer, he spotted the mihrab across the hall. An often unassuming niche carved into a mosque’s wall, it indicated the direction of Mecca. Al-Azhar’s mihrab was cut of smooth stone and arched with a wavy black-and-ivory stone inlay that had a nearly modern design.

Moving to a pillar closest to the mihrab , the man slipped off his backpack, then lay prone on the carpet in prayer. After several minutes, he gently pushed his pack to the side until it wedged against the base of the pillar. Spotting a pair of students walking in the direction of the entrance, he rose and followed them to the foyer, where he retrieved his shoes. Passing the bearded elder, he muttered, “Allahu Akbar,” then quickly stepped into the courtyard.

He pretended to briefly admire a rosette in the façade, then quickly made his way to the Barber’s Gate, which led out of the mosque compound. A few blocks away, he climbed into a small rental car parked on the street and drove in the direction of the Nile. Passing through a dingy industrial neighborhood, he turned onto the lot of a crumbling old brickyard and pulled behind its abandoned loading dock. There he pulled off his loose trousers and shirt, revealing a pair of jeans and silk blouse underneath. The eyeglasses were removed, along with a wig, and then the fake beard. The male Muslim student was no more, replaced by an attractive, olive-skinned woman with hard dark eyes and stylishly layered short black hair. Ditching her disguise in a rusty garbage bin, she hopped back into the car and rejoined Cairo’s sluggish traffic, crawling away from the Nile to the Cairo International Airport on the northeast side of town.

She was standing in line at the check-in counter when the backpack exploded. A small white cloud rose over al-Azhar Mosque as the prayer hall roof was blown off and the mihrab shattered into a pile of rubble. Though the explosion had been timed to detonate between daily prayers, several students and mosque attendants were killed and dozens more injured.

After the initial shock subsided, the Cairo Muslim community was outraged. Israel was blamed first, then other Western nations were targeted when no one claimed responsibility for the blast. In a few weeks, the prayer hall would be repaired and a new mihrab quickly installed. But to Muslims across Egypt and around the world, the anger at the assault on such a sacred site lasted much longer. Few could have recognized, however, that the attack was only the first salvo in a strategic ploy that would attempt to transform the very dominance of the entire region.

“Take the knife and cut it free.”

An angry scowl covered the Greek fisherman’s face as he handed his son a rusty serrated knife. The teenage boy stripped down to his shorts, then leaped off the side of the boat, the knife held firmly in one hand.

It had been nearly two hours since the trawler’s fishing nets had first snagged on the bottom, much to the surprise of the old Greek, who had safely dragged these waters many times before. He ran his boat in every direction, hoping to work the nets free, cursing loudly as his frustration mounted. Try as he might, the nets held firm. It would be a costly loss to cut away a portion of his nets, but the fisherman grudgingly accepted the occupational hazard and sent his boy over the side.

Though windswept on the surface, the waters of the eastern Aegean Sea were warm and clear, and at thirty feet down the boy could faintly see the bottom. But it was still well beyond his ability to free-dive, so he halted his descent and attacked the dangling nets with his knife. It took several dives before the last strand was cut free and the boy yanked to the surface with the damaged nets, exhausted and out of breath. Still cursing over his loss, the fisherman turned the boat west and putted off toward Chios, a Greek island close to the Turkish mainland, which rose from the azure waters a short distance away.

A quarter mile farther out to sea, a man studied the fisherman’s plight with curiosity. His frame was tall and lean yet robust, his skin deeply tanned from years in the sun. He lowered an old-fashioned brass telescope from his brow, exposing a pair of sea-green eyes that flickered with intelligence. They were reflective eyes, hardened by adversity and numerous brushes with death, yet they softened easily with humor. He rubbed his hand through thick ebony hair flecked with gray, then he stepped onto the bridge of the research vessel Aegean Explorer .

“Rudi, we’ve surveyed a good chunk of the bottom between here and Chios, haven’t we?” he asked.

A diminutive man with horn-rimmed glasses looked up from a computer station and nodded his head.

“Yes, our last grid ran within a mile of the eastern shore. With the Greek island situated less than five miles from Turkey, I don’t even know whose waters we’re in. We had about ninety percent of the grid complete when the AUV’s rear sensor blew a seal and flooded with salt water. We’ll be down at least two more hours while our technicians repair the damage.”

The AUV, or autonomous underwater vehicle, was a torpedo-shaped robot packed with sensing equipment that was dropped over the side of the research ship. Self-propelled and preprogrammed with a designated survey path, the AUV would cruise above the seafloor collecting data that was periodically relayed back to the surface ship.

Rudi Gunn resumed tapping at the keyboard. Dressed as he was in a tattered T-shirt and plaid shorts, nobody would have guessed he was the Deputy Director for the National Underwater and Marine Agency, the prominent government organization responsible for the scientific study of the world’s oceans. Gunn was normally confined to NUMA’s Washington headquarters rather than stationed aboard one of the turquoise-colored research vessels that the agency used to gather information on marine life, ocean currents, and environmental pollution. An adept administrator, he relished escaping the hubris of the nation’s capital and getting his hands dirty in the field, especially when his boss had escaped likewise.

“What sort of bottom contours have we seen in the shallows around here?”

“Typical of the local islands. A sloping shelf extends offshore a short distance before abruptly plunging to thousand-foot depths. We’re in about a hundred and twenty feet of water here. As I recall, this area has a fairly sandy bottom, with few obstructions.”