"I have encountered it before," he said. "I was trained in Ispahani, my lord, where the plant grows."

"I know where it grows," said the King of Kings. "What else do you have to tell me, physician?"

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.