He looked worried. “I’m sorry—I do not mean to be.”

She laughed again. “It’s fine!” She paused, then added: “It’s attractive.”

Ezio didn’t know how to respond to that, so he concentrated on the food. “This looks delicious.”

“Why, thank you.”

Ezio smiled. He didn’t want to break the mood, but a shadow had fallen over his thoughts. He mustn’t celebrate—or hope for anything—prematurely. He looked at her more seriously, and she immediately caught his frame of mind.

“Any luck with the final code?” he asked, as casually as he could.

“Ah, the code,” she replied, still a little playful, and Ezio was relieved. “Yes, I’ve solved it. A few hours ago. But you’ll have to be patient. You will get it soon enough.”

And she looked at him then in a way that broke down any defenses Ezio had left.

FIFTY-THREE

The last book was located in a place more difficult to get to. Niccolò Polo had managed to conceal it high on the front façade of the mosque of Haghia Sofia itself, above the great curved arch that stood before the principal dome of the former basilica.

Ezio chose to complete his mission in the wee hours before dawn, as then there would be the smallest number of people about. He reached the building unchallenged and carefully made his way to the exonarthex, looking up at the cliff of stone he had to climb. There were few crevices for his hookblade to get a grip, but after several unsuccessful attempts, he managed to climb to the spot Sofia had pinpointed. There, he found a weathered wooden panel, overhung with cobwebs.

He managed to belay himself to some nearby pipework which, after testing it, he found solid enough to take his weight, and he used the hookblade again to pry the panel open. The wooden board fell away, falling to the ground beneath with what to Ezio’s ears was a deafening, echoing clatter, and he hung there in the grey light of false dawn silently, praying that no one had been alerted by the noise. But after he had waited for three whole minutes, and there was no reaction, he reached into the cavity the board had concealed and from it drew the book he sought.

Once back on the ground, he sped away and found a quiet spot in the very park where he had dined with Sofia only the day before, and there examined his find. The book was a copy of Luitpold of Cremona’s Mission to Constantinople. He allowed himself to imagine for a moment Sofia’s pleasure at the sight of such a rarity, before turning to its front.

The blank pages glowed about as brightly as the thin streaks of dawnlight he could see away to the east across the Bosphorus. And a map of the city appeared, which, as he watched hopefully, resolved itself into focus, and on it appeared another light, brighter than the rest, clearly marking the Forum of the Ox.

Following the trail indicated in the book, Ezio made his way to the Forum, away in the west of the city, past the Second and Third Hills, and about midway between the Aqueduct of Valens to the north and the Harbor of Theodosius to the south. It was quite a walk, but when he arrived, it was still too early for anyone to be about. Ezio scanned the huge, deserted square for some kind of clue, but the marked spot in the book gleamed sharply, and he remembered the system of subterranean cisterns beneath the city. He concentrated his search and located, after a little time, a manhole, from which stone steps descended into the bowels of the earth.

Ezio closed the book and stowed it safely in his satchel. He replaced his hookblade with his pistol, checked his hidden-blade, and warily made his way downward.

He soon found himself in a vaulted cavern, on a stone embankment by which an underground river ran. Lit torches stood in sconces on the walls, and, as he crept quietly through a narrow, damp corridor, he heard, above the sound of rushing water, voices echoing, raised above the din the river made. Following the sound of them, he came upon two Byzantine Templars.

“What have you found?” one said. “Another key?”

“A door of some kind,” his comrade answered. “Bricked up with hard stone.”

Edging closer, rounding a corner, Ezio saw a number of soldiers a short distance away, standing on an old pier that jutted into the river. One of them was rolling a barrel off one of two waiting rafts.

“That sounds promising,” the first of the nearer Templars said. “The first key was found behind a similar door.”

“Is that so? And how did they open that door?”

“They didn’t. The earthquake did.”

On a signal from the men closer to Ezio, the other soldiers came up with the barrel, which they proceeded to lodge in place against the door. Ezio could now see that the opening was sealed with close-fitting blocks of some hard black stone, cut by a master mason.

“The earthquake! That was helpful,” said the second Templar. “And all we have is a few barrels of gunpowder.”

“This one should be big enough for the job,” replied the first.

Ezio’s eyes narrowed. He quietly released his gun and pulled back the hammer.

“If it isn’t, we’ll just get more,” the first Templar continued.

Ezio raised his arm and took aim, but the barrel of the gun caught the light of a torch as he did so and glinted, the unusual flash of light catching the eye of one of the soldiers.

“What?” he snapped.

He saw the gun and leapt in front of the barrel at the same moment that Ezio fired. The ball struck him, and he fell dead instantly.

Ezio swore to himself.

But the soldiers were onto him.

“It’s the Assassin! Let’s get out of here!”

Ezio tried to reload, but the soldiers were already making their way back toward the rafts. He followed them, desperate to stop them before they could raise the alarm. But as he reached the pier, they were already pushing off. By the time Ezio had leapt onto the second raft and was struggling to loose its moorings, the soldiers were in midstream, floating away.

He had cast off and was in pursuit when the thought struck him—were they scared of him, or were they leading him on? Well, it was too late now. He’d have to play this to the end.

As his raft was lighter, the current began to carry him closer. The soldiers seemed to be in a panic, but that didn’t stop them from priming bombs and loading muskets.

“We have gunpowder aboard, we should use it!” one cried.

“We’ll blast him out of the water,” said another, throwing a bomb, which exploded as it hit the water barely a foot ahead of Ezio’s prow.

“Give me some room,” yelled another soldier, trying to steady himself to take aim with his musket.