"Not a pet," he heard himself say in a near whisper. "In the China of my boyhood you never had enough food to keep your own belly full. Pets never survived. But when I was young my father and I would go to the river and watch the world go by. In the fall farmers would bring ducks to market from far inland. They would clip the wings of the ducks, thousands of ducks, and herd them downriver like vast flocks of sheep, the shepherds in sampans wearing black shirts and straw hats. Once I cried because I realized all the ducks were going to be killed and eaten." He sighed and looked toward the stars. "My father said don't be sad, that for a duck, it was a grand adventure, to float hundreds of miles out into the world, that the ducks would have chosen the river even if they knew their fate. Then he looked all about, very serious, to be sure no one listened, and told me a big secret. That sometimes ducks escaped and made it all the way to the sea and became famous pirate ducks."

No one spoke. No one laughed. He glanced at Marco, who was just nodding toward the horizon, as if he knew all about pirate ducks.

"After that," Shan continued, "every time we went to the river we took paper and inkstones and brushes. We wrote poems sometimes, about the grandeur of the river and how the moon looked when it rose over the silver water. Sometimes I just wrote directions to the sea. Then we folded the paper into little boats and sailed them into the duck herds."

They watched the stars. After a few minutes Marco outlined with his finger the constellations and challenged the Americans to tell the English names. The Northern Bushel they instantly knew as the Big Dipper, and the White Tiger as Orion the Hunter. The game continued good-naturedly. The Porch Way was Cassiopeia, and the Azure Dragon, Sagittarius.

Lokesh wandered from the group and sat on the sand twenty feet away, facing the darkness. He seemed to be looking at something, or at least toward something. Shan considered the direction and noted the position of the small mountain they sat beside. His friend was looking toward the Well of Tears. Lokesh had heard lost souls there.

"Xu had a file on Americans," Shan said suddenly. He was reluctant to break the mood, but the words had to be spoken. Everyone seemed to freeze, and they all watched him intently now. "A list of visiting groups." He looked at Abigail Deacon. "She has your name."

She shrugged. "I was in a delegation. A group of professors, looking at the ruins of the Silk Road market towns. The Marco Polo tour, they called it."

"But only one name was circled on the list. Yours."

The American woman looked at him uncertainly, almost resentfully, as if Shan were accusing her.

"There could be a dozen reasons, Warp," her husband said. "Your flight connections were delayed."

"Sure," Dr. Najan confirmed. "They had to arrange a special car for you to catch up. That's when we first met, the day you caught up with us. Warp, she always wanted to do things not on the itinerary. Asked for a guide to take her to some of the old watch towers on the mountains. Asked for special food." He looked at Shan as if scolding him. "So they circle a name. Lots of reasons."

"Lots of reasons," Shan agreed woodenly. Good reasons. And bad reasons. He surveyed the team that lived in the little outpost. So far from the world, so absorbed in the grand mystery of their science, it would be easy to forget the bad reasons. The Public Security reasons. The Ministry of Justice reasons.

"The killer," Marco said. "He's hiding far away by now. With Sui murdered, he'll know the knobs will be angry as hornets."

"No," Shan said, and he pulled from his pocket the list of names that Jakli had retrieved from Lau's office. "He killed a third boy," he reminded them. "He has a plan." Shan handed the paper to Deacon, who produced a tiny flashlight. His wife held the paper as Deacon held the light and the others gathered around.

"Twenty-three names," Shan explained. "The zheli. The list is from the school records, the official roll of participants. Anyone could get it. You could print it from a government computer in Urumqi or Lhasa or Beijing if you wanted. Eleven girls. Twelve boys, nine left alive. First Suwan-" Shan pointed to the center of the list, then to two others. "Alta, and Kublai."

"But there's no logic, no way to know what the killer is thinking," Marco said.

"Wrong." Shan pulled a pencil from his pocket and reached for the paper, then handed pencil and paper to Jakli. "Eliminate the girls," he said.

She studied the paper and quickly drew lines through eleven names.

"Then Suwan," he said, and she put an X by the boy's name. "And the boy with the dropka parents who was killed-" Jakli made another mark. "And then Kublai." She made a third mark and returned the paper to the American woman.

The first X was on the center of the page. The next two were the top two names of boys.

"That's his great logic?" Marco asked skeptically, as if he thought little of Shan's discovery. "Just go down the list?"

"He targeted Suwan, and when Suwan proved not to have what he wanted he started from the top of the list."

Abigail Deacon gasped and grabbed her husband's leg tightly. "Micah!" she said in alarm, pointing to a name midway down the list. The fourth boy from the top. After Kublai came a boy named Batu, then Micah Karachuk.

"You can't run to him," Marco warned as he watched the Americans. "It may be what the knobs expect. They're watching everywhere. It must be why they haven't acted on Sui's murder, hoping you'll come out of hiding. You're too conspicuous. You'd be seen in the mountains, reported. Then Micah-" Marco shrugged. "Micah needs you to stay where you are."

Deacon nodded. "We made up the name," the American said in a near whisper as he stared at the list, then began to explain their decision to entrust their son to Lau. Soon after they had arrived in the desert it had become clear that their cavern at Sand Mountain was no place for a ten year old. He had met some of the zheli, had met Khitai, at a horse festival in the spring. Micah spoke Mandarin, as did most of the children, and was quickly picking up enough of the Turkic tongue to get by. He loved animals. The zheli was the perfect answer. He would be well protected, watched over by Lau and the nomads. "Besides," Deacon said, trying to lighten his wife's mood, "He's such a mischievous pup, the discipline of the sheep camps would be great for him. He loves it. Been with four different families so far."

"Lau knew this?" Shan asked.

"She suggested it. But kept it secret from the others. So Micah was just a Kazakh boy from a distant part of Xinjiang. Several of the children only spoke Mandarin, because they had been raised in government schools, so his not speaking the clan's tongue was not suspicious."

"So none of the children knew?" Shan asked.

"Not supposed to. But you know ten-year-old boys. Last month, Lau told us Micah had bragged about his parents, then at a class he handed around a jar of American peanut butter. We didn't know he had taken one. Then when I went to see him, he surprised me with three of his friends. Made me promise to come to some classes just before we left Xinjiang, to talk about our discoveries."

Shan stared at Deacon a moment. The Americans were planning to leave soon. Had the boys' killer learned this, and been forced into desperate action?