Nowhere to hide, it seemed. Rustem took a deep breath.

"I also smelled it elsewhere in this room, great lord. Before I put the herbal scent to the fire."

There was a silence.

"I thought that might be so." Shirvan the Great looked coldly up at him. "Where?" One word only, hard as a smith's hammer.

Rustem swallowed again. Tasted something bitter: the awareness of his own mortality. But what choice did he now have? He said, "On the hands of the prince, great king. When he bade me save your life, at risk of my own."

Shirvan of Bassania closed his eyes briefly. When he opened them, Rustem saw a black rage in their depths again, despite the drug he had been given. "This… distresses me," said the King of Kings very softly. What Rustem heard was not distress, however. It suddenly occurred to him to wonder if the king had also detected kaaba on the arrowhead and shaft. He had been ingesting it for twenty-five years. If he had known the poison, he had allowed three physicians to handle it today without warning them, and had been about to let Rustem do the same. A test of competence? When he was on the brink of dying? What sort of man…? Rustem shivered, could not help himself.

"It seems," said Great Shirvan, "that someone besides myself has been protecting himself against poisons by building up a resistance. Clever. I have to say it was clever." He was silent a long time, then: "Murash. He would have made a good king, in fact."

He turned away and looked out the window; there was nothing to see in the darkness. They could hear the sound of the wind, blowing from the desert. "I appear," the king said. "to have ordered the death of the wrong son and his mother." There was another, briefer silence. "This distresses me," he said for a second time.

"May these orders not be rescinded, great lord?" Rustem asked hesitantly.

"Of course not," said the King of Kings.

The finality in the quiet voice was, Rustem would later decide, as frightening as anything else that day.

"Summon the vizier," said Shirvan of Bassania, looking out upon night. "And my son."

Rustem the physician, son of Zorah, wished ardently in that moment to be home in his small house, shuttered against the wind and dark, with Katyun and Jarita, two small children peacefully asleep, a late cup of herbed wine at his elbow and a fire on the hearth, with the knocking of the world at his door something that had never taken place.

Instead, he bowed to the man lying on the bed and walked to the doorway of the room.

"Physician," said the King of Kings.

Rustem turned back. He felt afraid, terribly out of his depth.

"I am still your patient. You continue to be accountable for my well-being. Act accordingly." The tone was flat, the cold rage still there.

It did not take immense subtlety to understand what this might mean.

Only this afternoon, in the hour when a wind had arisen in the desert, he had been in his own modest treatment room, preparing to instruct four pupils on couching simple cataracts according to the learned devisings of Merovius of Trakesia.

He opened the door. In the torchlight of the corridor he saw a dozen tired-looking courtiers. Servants or soldiers had brought benches; some of the waiting men were sitting, slumped against the stone walls. Some were asleep. Others saw him and stood up. Rustem nodded at Mazendar, the vizier, and then at the young prince, standing a little apart from the others, his face to a dark, narrow window-slit, praying.

Vinaszh the garrison commander-the only man there that Rustem knew-raised his eyebrows in silent inquiry and took a step forward. Rustem shook his head and then changed his mind. You continue to be accountable, the King of Kings had said. Act accordingly.

Rustem stepped aside to allow the vizier and the prince to walk into the room. Then he motioned for the commander to enter as well. He said nothing at all, but locked eyes with Vinaszh for a moment as the other man went in. Rustem followed and closed the door.

'Father!" cried the prince.

"What is to be has long ago been written," murmured Shirvan of Bas-sania calmly. He was propped up on pillows, his bare chest wrapped in the linen bandages. "By the grace of Perun and the Lady, the designs of Black Azal have been blighted for a time. The physician has removed the arrow."

The vizier, noticeably moved, passed a hand before his face and knelt, touching the floor with his forehead. Prince Murash, eyes wide as he looked at his father, turned quickly to Rustem. "Perun be exalted!" he cried, and, striding across the floor, he reached forward and seized both of Rustem's hands in his own. "You shall be requited, physician!" exclaimed the prince.

It was with a supreme act of self-control and a desperate faith in his own learning that Rustem did not violently recoil. His heart was pounding furiously. "Perun be exalted!" Prince Murash repeated, turning back to the bed and kneeling as the vizier had done.

"Always," agreed the king quietly. "My son, the assassin's arrow rests there on the chest beneath the window. There was poison on it. Kaaba. Throw it in the fire for me."

Rustem caught his breath. He looked swiftly at Vinaszh, meeting the soldier's eyes again, then back to the prince.

Murash rose to his feet. "Joyfully will I do so, my father and king. But poison?" he said.'How can this be?" He crossed to the window and reached carefully for a swath of linen that lay beside Rustem's implements.

"Take it in your hands, my son," said Shirvan of Bassania, King of Kings, Sword of Perun. "Take it in your bare hands again."

Very slowly the prince turned to the bed. The vizier had risen now and was watching him closely.

"I do not understand.You believe I handled this arrow?" Prince Murash said.

"The smell remains on your hands, my son," said Shirvan gravely. Rustem cautiously took a step towards the king. The prince turned- outwardly perplexed, no more than that-and looked at his hands and then at Rustem. "But then I will have poisoned the doctor, too," he said.

Shirvan moved his head to look at Rustem. Dark beard above pale linen bandages, the eyes black and cold. Act accordingly, he had said. Rustem cleared his throat. "You will have tried," he said. His heart was pounding. "If you handled the arrow when you shot the king then the kaaba has passed through your skin and is within you by now. There is no menace to your touch, Prince Murash. Not any more."

He believed this was true. He had been taught that this was so. He had never seen it put to the test. He felt oddly light-headed, as though the room were rocking slightly, like a child's cradle.

He saw the prince's eyes go black then-much like his father's, in fact. Murash reached to his belt, whipped out a knife, turned towards the bed.

The vizier cried out. Rustem stumbled forward, unarmed.

Vinaszh, commander of the garrison at Kerakek, killed Prince Murash, third of the nine sons of Shirvan the Great, with his own dagger, flung from near the doorway.

The prince, a blade in his throat, dropped his weapon from lifeless fingers and slowly toppled across the bed, his face to his father's knees, his blood staining the pale sheets red.

Shirvan did not move. Neither did anyone else.

After a long, frozen moment the king turned from gazing down at his dead son to look over at Vinaszh and then at Rustem. He nodded his head slowly, to each of them.

"Physician, your father's name was…?" A tone of detached, mildly curious interrogation.

Rustem blinked. "Zorah, great lord."

"A warrior-caste name."

"Yes, lord. He was a soldier."

"You chose a different life?"

The conversation was so implausible it was eerie. Rustem felt dizzied by it. There was a dead man-a son-sprawled across the body of the man with whom he was speaking thus. "I war against disease and wounds, my lord." What he always said.