The Judas Strain (Sigma Force 4)

Gray leaned closer, beginning to understand the direction of Vigor's track. "And Hebrew is read opposite from English. From right to left."

Seichan traced a finger across the paper and read backward. "H. A. G. I. A."

"Hagia," Vigor pronounced carefully. "The word means 'divine' in Greek."

Gray's eyes had narrowed—then widened with sudden understanding.

Of course.

"What?" Siechan asked.

Kowalski scratched the stubble on his head, equally clueless.

Vigor stood and drew them all up. He walked them to face the city. "On his journey home, Marco Polo crossed through Istanbul, named Constantinople at the time. Here is where he crossed from Asia and finally reentered Europe, a significant crossroads of sorts."

The monsignor pointed out to the city, toward one of the ancient monuments. Gray had noted it before. A massive flat-domed church, half covered in black scaffolding as restoration work was under way.

"Hagia Sophia," Gray said, naming the structure.

Vigor nodded. "It was once the largest Christian church in all the world. Marco himself commented on the wonders of its airy spaces. Some people mistake Hagia Sophia to mean 'Saint Sophia,' but in fact, the true name of the structure is the Church of Divine Wisdom, which can also be interpreted as the Church of Angelic Wisdom."

"Then that's where we must go!" Seichan said. "The first key must be hidden there." She swung away.

"Not so fast, young lady," Vigor scolded.

The monsignor returned to his backpack, reached inside, and drew out a cloth-wrapped object. Gently resting it on the table, he peeled back the layers to reveal a flat bar of dull gold. It appeared very old. It bore a hole at one end, and its surface was covered in a cursive script.

"Not angelic," Vigor said, noting Gray's attention to the lettering. "It's Mongolian. It reads, 'By the strength of the eternal heaven, holy be the Khan's name. Let he who pays him not reverence be killed.'"

"I don't understand," Gray said, crinkling his brow. "Did this belong to Marco Polo? What is it?"

"In Chinese, it is called apaitzu. In Mongolian, a gerege."

Three blank faces stared back at Vigor.

Vigor nodded to the object. "In the modern vernacular, it's a VIP passport. A traveler bearing this superpassport could demand horses, supplies, men, boats, anything from the lands governed by Kublia Khan. To refuse such aid was punishable by death. The Khan granted such passes to those ambassadors who traveled in his service."

"Nice," Kowalski whistled—but from the glint in the man's eyes, Gray suspected it was the gold more than the story that had won the man's awe.

"And the Polos were given one of these passports?" Seichan asked.

"Three of them, in fact. One for each Polo. Marco, his father, and his uncle. In fact, there is an anecdote concerning these passports. A famous one. When the Polos arrived back in Venice, it was said no one recognized them. The trio came worn, tired, in a single ship. Looking little better than beggars. None would believe them to be the long-vanished Polos. Upon stepping to shore, the trio sliced open the seams of their clothes, and a vast wealth of emeralds, rubies, sapphires, and silver spilled out. Included in this treasure trove were the three golden paitzus, described in great detail. But after this story, the golden passports vanished away. All three of them."

"The same number as the map's keys," Gray commented.

"Where did you find this?" Seichan asked. "In one of the Vatican museums?"

"No." Vigor tapped the open notebook with the angelic script. "With the help of a friend, I discovered it under the marble tile upon which this inscription was written. In a secret hollow beneath the marble."

Like the friar's cross, Gray realized. Buried in stone.

Seichan swore slightly. Again the prize had been right under her nose all along.

Vigor continued, "I believe this is one of the very paitzus granted to the Polos." He faced them all. "And I believe this is the first key."

"So the clue leading to Hagia Sophia . . ." Gray began.

"It's pointing to the second key," Vigor finished. "Two more missing passports, two more missing keys."

"But how can you be so sure?" Seichan asked.

Vigor flipped the gold bar over. Inscribed in great detail, a single letter adorned the back side. An angelic letter.

Vigor tapped the letter. "Here is the first key."

Gray knew he was right. He glanced up, toward the massive church. Hagia Sophia. The second key had to be hidden there, but it was a huge structure. It would be like finding a golden needle in a haystack. It could take days.

Vigor must have read his worry. "I already have someone scouting ahead at the church. An art historian from the Vatican who helped me back at the Tower of Wind with the angelic riddle."

Gray nodded. As he studied the single letter, he could not shake a deeper worry. For his two friends. Monk and Lisa. Already in harm's way. If he could not contact Washington safely, perhaps there was another way he could help his friends: by beating the Guild to whatever lay at the end of this mystery.

To find the City of the Dead, to discover the cure.

Before the Guild did.

As he stared toward the sunrise, Gray remembered Vigor's words about Istanbul being the crossroad of Marco's journey. In fact, since its founding, the ancient city had been the crossroads of the geographic world. To the north lay the Black Sea, to the south the Mediterranean. The Bosporus Strait, a major trade route and seaway, flowed between them. But more important to history, Istanbul straddled two continents. It had one foot in Europe, the other in Asia.

The same could be said about the city's place in the gulf of time.

One foot in the present, one in the past.

Forever at a crossroads.

Not unlike himself.

As he pondered this, a cell phone chimed to the side. Vigor turned and fished his phone out of the backpack's front pocket. He studied the caller ID with a frown. "It's a D.C. area code," Vigor said.

"Must be Director Crowe," Gray warned. "Don't mention anything. Stay on as short as possible to avoid any trace. In fact, we should pull the cell's battery afterward so it's not passively tracked."

Vigor rolled his eyes at his paranoia and flipped his phone open. "Pronto," he greeted.

Vigor listened for a few moments, his brow growing more and more furrowed. "Chi "Parla?" he asked with a bit of heat. Whatever he heard seemed to shake him up. He turned and held the phone out for Gray.