Barbarians they might have been, but the Mongols lived by strict laws and had much the same kind of police system that any civilized city did. Faster and more efficient than most, in fact. We had hardly finished dressing when a military officer rapped on the front door and opened it, without waiting for us to open it for him.

He questioned me, ignored Agla. I told him exactly what happened, leaving out only Agla’s “examination” of the two corpses.

“Who might have sent assassins against you?” the officer asked. He seemed truly concerned. Things like this did not happen often in the Mongol capital.

I kept my opinion to myself. “I have no way of knowing,” I told him. “We arrived here only yesterday.”

“Who are your enemies?”

I shook my head. “I am a stranger here, from a faraway land. I did not think I had any enemies here. Perhaps they mistook me for another.”

He looked unconvinced, but he said, “Perhaps. Stay here until notified otherwise. You will be guarded by my men.”

House arrest is what it amounted to. The Mongols did not like trouble in their midst, and they intended to get to the bottom of this. Two warriors parked themselves outside our door. Servants brought food and fresh clothes to us. As usual, they could find no boots large enough to fit me. I kept my sandals. They had stood me in good stead all these weeks, even when I had had to wrap them with skins and furs as we rode through the high passes of the Tien Shan.

“It is the Dark One,” Agla brooded, once we were alone. “He seeks your death.”

She insisted on tasting the food that the servants brought before letting me eat it. She even inspected the clothing for hidden charms or potions.

“A man can be poisoned through the skin,” she warned me. “I know of a poultice that can kill a strong warrior, once it touches his skin for a few moments.”

Nerve poisons in the thirteenth century? I deferred to her superior knowledge of the time. My attention focused on another matter. I agreed with Agla that no one except Ahriman could possibly want to kill me. But why? Why were we both here? My mission was to kill him, I knew. Was he under the same compulsion? Was it our destiny to hunt each other through all of time, playing an eternal prey-and-predator game for the amusement of Ormazd and whatever other gods there be?

I refused to believe that I was nothing more than an elaborate toy. Ahriman sought to kill me not merely for the sport of it, but to prevent me from thwarting his plans. He sought nothing less than the destruction of the whole human race, forever, for all of time and space, even if it meant destroying the very fabric of the continuum and demolishing the entire universe of space-time. My unalterable mission was to prevent him from doing that, and the only way I could accomplish it, unfailingly and permanently, was to kill Ahriman.

I am not an assassin, I told myself. I am not a murderer. I am a soldier, fighting for the life of the entire human race against a ruthless alien who would snuff us out like a candle flame. If I must kill Ahriman, it is because only his death can ensure the life of humankind.

But still I was troubled. No matter how hard I tried to convince myself, it still boiled down to what Ormazd had told me so long ago in the future: my mission is to find Ahriman and kill him.

How many times? I suddenly wondered. When is a man finally, unquestionably dead? Ahriman had killed Aretha in the twentieth century, and yet Agla lived here beside me. I myself had died, but still breathed and moved and loved. Is the cycle endless?

I sank onto the soft mattress of our bed, too soul-weary to contemplate an eternity of hunting Ahriman, of death after death, murder after murder. Agla, sensing my despair, tried to comfort me.

Then someone knocked at our door. A polite but firm tapping, three distinct raps.

I went to the door and opened it. It was night now, and the whole inner compound of the ordu was lit by the crackling flames of the twin bonfires. Ogotai’s silken tent swayed in a breeze that was not interrupted by hill or tree for hundreds of miles.

Standing in front of me was an elderly, slender Chinese in exquisite robes of sky blue and silver. In his high, peaked hat he was almost my height. With the bonfires at his back, it was difficult for me to make out the features of his face.

“I am Ye Liu Chutsai, advisor to the High Khan,” he said in the soft, high voice of an old man. “May I enter?”

The mandarin stood patiently at the doorway. The two Mongol guards were squatting on the bare ground a few yards from the door, gobbling their supper from wooden bowls. Their lances and bows were on the ground next to them, their swords at their sides.

“Yes, of course,” I said to the mandarin. “Please come in.”

He had the trick of walking so smoothly that it looked as if he was standing on a small rolling cart, under his floor-length robes, and was actually being wheeled across the threshold. I introduced him to Agla, who bowed very low to him, then busied herself building the fire higher in the hearth.

Ye Liu Chutsai looked older than any man I had seen among the Mongols. His wispy beard and mustache were completely white, as was the long queue that hung down his back. He stood in the middle of the bare little room, hands tucked inside his wide sleeves.

I gestured to the only chair in the room, a heavy, stiff thing of wood. “Please sit down, sir.”

He sat. Agla ducked into the bedroom and brought out two cushions. She offered them to the mandarin, who refused them with a slight shake of his head and a small smile. She and I sat on them, at the feet of the elderly Chinese.

“I should begin by explaining who I am,” he said so softly that I had to strain slightly to hear him over the crackle of our fire. Its warmth felt good on my back.

Agla said, “Your name is known as the right hand of the High Khan.”

He bowed his head again in acknowledgment.

“Since the original High Khan was still called by his birth name, Timujin, I have served the Mongols. I was only a youth when they swept through the Great Wall and ravaged Yan-king, the city where I was born. I was taken into slavery by the Mongols because I was a scribe. I could read and write. Although the Mongol warriors did not appreciate that, Timujin did.”

“It was he who became Genghis Khan?” I asked.

“Yes, but to use either of these names before the Mongols is not wise. He is called the High Khan. He was the father of Ogotai, the current High Khan. He was the man who directed the Mongol conquest of China, of High Asia, of the hosts of Islam. He was the greatest man the world has known.”

It was not my place to contradict him. The elderly mandarin did not seem like the kind who would bestow praise foolishly or insincerely. He believed what he said, and for all I knew he may have been right.

“Today the empire of the Mongols stretches from the China Sea to Persia. Hulagu is preparing to conquer Baghdad. Subotai is already on the march against the Russians and Poles. Kubilai, in Yan-king, dreams of subduing the Japanese on their islands.”

“He should forego that dream,” I said, recalling that Kubilai’s invasion fleet was wrecked by a storm that the Japanese called The Divine Wind, Kamikaze.

Ye Liu Chutsai looked sharply at me. “Why do you say that?” he demanded. “What do you prophesy?

Agla gave me a warning glance. Prophets trod a dangerous path among these people.

“I prophesy nothing,” I replied, as offhandedly as I could manage. “I merely made a comment. After all, the Mongols are horse warriors, not sailors. The sea is not their element.”

The mandarin studied my face for long moments. At last he replied, “The Mongols are indeed the fiercest warriors in the world. They are not sailors, true. But neither are they administrators, or scribes, or artisans. They use captives for those tasks. They will find sailors enough among the Chinese.”