Pitt’s satisfaction was short-lived. Eyeing a green-tiled wall on the opposite side of the prayer hall, he spotted a man in sunglasses looking in his direction. It was the same man who had gawked at Loren outside the hotel.

Without saying a word, Pitt slowly herded Loren toward the exit, consciously staying close to a group of German tourists on a guided tour. He casually surveyed the crowd scattered about the mosque, trying to discern whether Sunglasses had any partners. Pitt noticed a thin Persian man with a bushy mustache shuffling along nearby, a serious scowl on his face. He appeared incongruous among the other tourists standing with their necks craned toward the ceiling. It seemed unlikely that the Topkapi thieves would have tracked them down so quickly, though Pitt recalled the threatening words of the woman in the cistern. He decided to find out for sure.

Following the Germans out of the prayer hall, Pitt and Loren pulled on the shoes they had removed earlier and followed the tour group into the courtyard. Pitt watched from the corner of his eye as the Persian followed suit.

“Stay here,” Pitt told Loren, then turned and quickly strode across the marble tile toward the man.

The Persian immediately turned, pretending to study a nearby column behind him. Pitt strode right up and gazed down at the man, who stood a head shorter.

“Excuse me,” Pitt said. “Can you tell me who’s buried in Atatürk’s tomb?”

The man at first avoided Pitt’s gaze, peering instead toward the prayer hall exit where Sunglasses now stood. Spotting a shake of the head, he turned and faced Pitt with a look of contempt.

“I wouldn’t know where that dog lies,” he spat, his eyes glistening with an arrogant intimidation born of a hardened life in the streets. An undercover police agent he was clearly not. When Pitt noticed the telltale bulge of a holstered handgun under the man’s loose shirt, he decided not to press the issue. He gave the man a cold, knowing look, then turned and stepped away. Walking back to Loren, he half expected a bullet in the back and silently hoped the crowds and mosque security were sufficient deterrents to spare an immediate attack.

“What was that about?” Loren asked as he returned.

“Just checking the time. Come on, let’s see if we can catch a cab.”

The German tour group was slowly moving toward the courtyard exit, but Pitt grabbed Loren’s hand and dragged her past them, slipping out before they converged on the doorway. Pitt didn’t bother looking back, knowing full well that Sunglasses and the Persian would be in pursuit. Prodding Loren to the street, he got lucky and commandeered a cab that was off-loading an elderly pair of tourists out front.

“To the Eminönü ferry docks, as fast as you can,” he directed the cabdriver.

“Why all the rush?” Loren asked, slightly agitated at being hustled into the car.

“I think we are being tailed.”

“That man you spoke to inside the mosque?”

Pitt nodded. “And another fellow wearing sunglasses who I saw earlier outside our hotel.”

As the cab pulled into traffic, Pitt looked out the back window. A small orange sedan screeched up to the curb with a lone driver inside. Pitt looked across the mosque grounds to see the German tourist group still congregated around the mosque exit. He smiled as he spotted the Persian clumsily fighting his way through the thick crowd.

“Why don’t we go to the police?” Loren asked, a rising note of alarm in her voice.

Pitt flashed a reassuring grin. “What, and ruin our one and only relaxing day in Istanbul?”

The yellow taxi quickly melted into traffic, leaving the domed mosque and its minarets in the rearview mirror. Had the driver turned north and wound through the crowded maze of the historic old city, he would have easily lost the orange sedan to thick traffic. But the judicious cabdriver, thoughtful to make good time, instead turned south and headed toward a divided motorway called the Kennedy Caddesi.

The pursuers desperately attempted to catch up. The orange sedan sped away from the mosque after picking up its two passengers, nearly getting sideswiped by a tourist bus as it wove through traffic.

“I think they turned right,” the driver said in a hesitant voice.

“Go,” Sunglasses directed from the front passenger seat while nodding at the driver to follow his instincts.

The car turned south, bolting through a red light, before slowing behind a procession of crawling vehicles. Seated in the backseat, the Persian suddenly pointed down the road, spotting a yellow cab two blocks ahead turning onto the Caddesi.

“I think that is their cab,” he shouted.

The driver nodded, his knuckles tightening around the steering wheel. There was little he could do to prod his way through the clogged traffic, and he anxiously cursed the surrounding vehicles while the seconds ticked by. Finally spotting a break in oncoming traffic, he burst down the left lane for a block, then nosed back into the right lane. The traffic moved forward, and he quickly entered the Caddesi, flooring the accelerator and weaving down the highway like a Formula 1 racer.

The highway looped around the eastern boundary of Topkapi, hugging the Bosphorus shoreline. Traffic moved briskly as the road turned north then west along the Golden Horn, a natural water inlet that divided the European sector of Istanbul. Pitt looked down at the waterway, admiring a large green dredge ship that was churning the waters off the shoreline. As the cab approached the Galata Bridge, which stretched north over the Golden Horn into the district of Beyoğlu, a throng of cars and buses suddenly materialized, impeding movement to a crawl. The cab exited the Caddesi at the first opportunity, snaking down to a ferry dock near the base of the bridge.

“Boğaz Hatti dock at Eminönü,” the cabdriver announced. “The next ferry departure will be right over there,” he added with a wave of his arm. “If you hurry, you can just catch it.”

Pitt paid the driver, adding a healthy tip, then surveyed the road behind them as he exited the cab. Seeing no sign of the orange sedan, he casually escorted Loren to the ticket window.

“You just can’t stay away from the water, can you?” Loren said, eyeing several large ferryboats on the waterfront.

“I thought a relaxing cruise on the Bosphorus was just what the doctor ordered.”

“Actually, that does sound enticing,” she admitted, relishing some fresh-air sightseeing. “Just so long as we’re alone and there’s lunch involved.”

Pitt grinned. “Lunch is guaranteed. And I think we’ve lost our friends.”

Purchasing their tickets, they walked down one of the busy docks and boarded a modern passenger ferry, grabbing some seats by a window. A triple blast of the ship’s horn signaled its departure before the gangway was pulled aside.

On the road out front, the orange sedan screeched to a halt, its two passengers flying out of the side doors. Bypassing the ticket booth, they sprinted down to the dock, only to watch the ferryboat churn into the strait. Panting to catch his breath, Sunglasses stared at the ferry, then turned to the Persian.

“Find us a boat,” he hissed. “Now!”

At twenty miles in length and seldom more than a mile wide, the Bosphorus Strait was at once one of the world’s busiest and most scenic waterways. Dividing the heart of Istanbul, it had been a historic trading route, utilized by the ancient Greeks, Romans, and Byzantines. In modern times, it had become a major conduit for Russia, Georgia, and other countries bordering the Black Sea. Tankers, freighters, and containerships constantly clogged the narrow waterway that split the European and Asian continents.

The ferryboat steamed north at a comfortable clip, easing past the hilly skyline of Istanbul under a clear blue sky. The vessel soon passed under the Bosphorus Bridge and later the Fatih Sultan Mehmet Bridge, both towering suspension bridges that rose high above the waterway. Pitt and Loren sipped hot tea while surveying the neighboring boat traffic and the hillside architecture. The crowded shoreline slowly receded into a line of stately waterfront mansions, diplomatic missions, and former palaces that resided against a green forested backdrop.