She followed him as he led the way to the back of the house and into a small room opening onto a garden. Cupboards and chests of carved wood lined three walls, and a worn wooden table stood in the center with brass scales and weights and a mortar and pestle. There were pieces of Egyptian paper and oiled silk in piles, and long-handled spoons of silver, bone, and ceramic set neatly beside glass vials.

“From Nicea?” Shachar repeated curiously. “And you come to practice in Constantinople? Be careful, my friend. The rules are different here.”

“I know,” she answered. “I use them”-she indicated the cupboards and drawers-“only when necessary to heal. I’ve learned all my saints’ days appropriate to every illness, and every season or day of the week.” She looked at him, searching his face for disbelief. She knew too much anatomy and far too much of Arabic and Jewish medicine to believe, as Christian doctors did, that disease was due solely to sin, or that penitence would cure it, but it was not something the wise said aloud.

There was a flicker of understanding in Shachar’s eyes, but the dark, subtle amusement did not reach his lips. “I can sell you most of what you need,” he said. “What I do not have, perhaps Abd al-Qadir can supply.”

“That would be excellent. Do you have Theban opium?”

He pursed his lips. “That is one for Abd al-Qadir. Do you need it urgently?”

“Yes. I have a patient I am treating and I have little left. Do you know a good surgeon if the stone does not pass naturally?”

“I do,” he replied. “But give it time. It is not good to use the knife if it can be avoided.” He worked as he spoke, weighing, measuring, packing things up for her to take, everything carefully labeled.

When he was finished, she took the parcel and paid him what he asked.

He studied her face for a few moments before making his decision. “Now let us see if Abd al-Qadir can help you with the Theban opium. If not, I have some that is less good, but still perfectly adequate. Come.”

Obediently she followed, looking forward to meeting the Arab physician and wondering if perhaps he was the surgeon Shachar would recommend for Basil. How would her very Greek patient accept that? Perhaps it would not be necessary.

ZOE CHRYSAPHES STOOD AT THE WINDOW OF HER FAVORITE room and stared across the rooftops of the city to where the sunlight streamed onto the Golden Horn till the water was like molten metal. Her hands caressed the stones in front of her, still warm in the last glow of the day. Constantinople was spread out below her like a jeweled mosaic. The ancient magnificence of the Aqueduct of Valens was behind her, its arches sweeping in from the north like a Titan from the Roman past, an age when Constantinople was the eastern pillar of an empire that ruled the world. The Acropolis, far to the right, was far more Greek and therefore more comfortable to her, her language, her culture. Although its great days had been before she was born, the elderly woman still felt a pride in the thought of it.

She could see the tops of the trees that hid the ruins of the Bukoleon Palace, where her father had taken her as a child. She tried to bring back those bright memories, but they were too far away and slipped out of her grasp.

The radiance of the setting sun momentarily hid the squalor of the unmended walls, covering their scars with a veil of gold.

But Zoe never forgot the pain of the enemy invasion, of ignorant and careless feet trampling what had once been beautiful. She looked at the city now and saw it as exquisite and defiled, but still throbbing with a passion to taste every last drop of life and drain it to the lees.

The light was kind to her. She was past seventy, but the skin was smooth over her cheekbones. Her golden eyes were shadowed and hooded under her winged brows. Her mouth had always been too wide, but the curve of it was full. The luster of her hair was less than it had been and closer to brown than chestnut-there was only so much that herbs and dyes could do-but it was still beautiful.

She stared a few moments longer at the glittering skyline of Galata as the torches were lit. The east was fading rapidly, and the harbor was masked in purple. The spires and domes were sharper against the enamel blue of the sky. In thought she communed with the heart of the city, that part of it that was more than palaces or shrines, more even than the Hagia Sophia or the light on the sea. The soul of Constantinople was alive, and that was what she had seen raped by the Latins when she was a small child.

As the sun slid behind the low clouds and the air grew suddenly cold, she turned away at last. She stepped back into the room and its dazzling torchlight. She could smell the tar burning, see the faint shimmer of the flames in the draft. Between two of the finest tapestries in dark reds, purples, and umber, there was a gold crucifix more than a foot’s length from top to bottom. She walked over and stood in front of it, staring at the Christ in agony. It was exquisitely wrought: Every fold of His loincloth, the sinews of His limbs, His face hollowed by pain, all were perfect.

Gently she reached up, eased it off its hook, and held it in her hands. She did not need to look at it, knowing as she did every line and shadow of the images on each of the four arms. Her fingers felt them now, going over them softly, like faces of those she loved; except that it was hate that moved Zoe, the envisioning over and over again of revenge: exquisite, slow, and complete.

On the top, above the Christ, was the family emblem of the Vatatzes, who had ruled Byzantium in the past. It was green, with a double-headed eagle in gold, above each head a silver star. They had betrayed Constantinople when the crusaders had come, fleeing the invaded city and taking with them priceless icons, not to save them from the Latins, but to sell for money. They had run like cowards, thieving from the holy sanctuaries as they went, abandoning to fire and the sword what they could not carry.

On the right arm was the emblem of the Doukas family, also rulers until more recently. Their arms were blue, with an imperial crown, a two-headed eagle with a silver sword in each claw; they were traitors as well, plunderers of those already robbed, homeless, and helpless. They would know in time what it was to starve.

On the left arm was the emblem of the Kantakouzenos, an imperial family older still; their arms were red, with the double-headed eagle in gold. They had been greedy, blasphemous, without honor or shame. To the third and fourth generation, they would pay. Constantinople did not forgive the violation of her body or her soul.

On the main trunk, against which hung the figure of Christ, was the emblem of the worst of them all, the Dandolo of Venice. Their coat of arms was just a simple lozenge horizontally halved, white above, red below. It was Doge Enrico Dandolo, over ninety years old and blind as a stone, who had stood in the prow of the leading ship of the Venetian fleet, impatient to invade, despoil, and then burn the Queen of Cities. When no one else had had the courage to be the first ashore, he had leapt down onto the sand, sightless and alone, and charged forward. The Dandolo family would pay for that as long as the scorch marks of ruin scarred the stones of Constantinople.

She heard a sound behind her, a clearing of the throat. It was Thomais, her black serving woman, with her close-cropped head and beautiful, fluid grace. “What is it?” Zoe asked without taking her eyes off the cross.

“Miss Helena has come to see you, my lady,” Thomais replied. “Shall I ask her to wait?”

Zoe carefully replaced the cross on the wall and stepped back to regard it. Over the years since her return from exile, she had put it back up there hundreds of times, always perfectly straight.