Tsomo pulled Shan by the arm as the nun led an awestruck Yeshe along the manuscripts, away from the door. They moved up more steps to an inner chamber deep inside the mountain. It had the air of a classroom. There were only two lamps in the room, both on a small altar. At the far end were shelves of pottery, most of which was broken; above the pottery were symbols painted on the wall. There was a carpet on the floor, and seat cushions on which two monks sat.

One of the monks was facing away from them toward the altar. The other, an older, austere man with twinkling eyes, greeted them with a slight bow from his waist. "You are most persistent, Xiao Shan," the monk said in Mandarin. There was the sound of bare feet scampering behind him. Three boys in the robes of students moved inside and sat behind the monk who spoke. They looked at Shan with round, bewildered expressions.

"You have presented us with quite a dilemma, you know," the old lama continued.

"I am only investigating a murder." Shan's eyes moved back to the symbols above the pottery. With a start he realized he had seen them before, made in chalk at the ledge above the Dragon Throat Bridge.

"Yes. We know. The prosecutor was killed not far from here. Sungpo the hermit is detained. The 404th is on strike. Seventeen priests have been tortured. A prisoner has been executed. The Public Security Bureau is poised for another atrocity."

"You know more about the 404th than I do," Shan said in wonder. "Are you the abbot of this place?"

The man's smile seemed to cover his entire face. "There is no abbot here. My name is Gendun. I am just a simple monk." As he spoke his fingers worked rosary beads carved of dark reddish wood. "Will they send you back there, when it is done?"

Shan paused, considering the man, not the question. "Unless they choose a worse place."

Another boy appeared with a pot of buttered tea and filled bowls in silence. From somewhere came the sound of tsingha, the tiny, chimelike cymbals of Buddhist worship.

"You said I was a dilemma," Shan said as he accepted one of the bowls.

"Yerpa is the secret room of a house never seen, built in a land of shadow. Three hundred years ago one of our scholars wrote that in a book." Gendun paused and smiled at Shan. "We write books for each other sometimes, since no one else can see them. He said we were between worlds here. A stopping-over place. Not of the earth, not of the beyond. He called it the mountain of dreams."

"The eye of the raven," the other priest said, still with his back to them. Something in his voice sounded familiar.

Tsomo smiled. "In the library there is a poem, about the dead of winter. Among a hundred snowy mountains, it says, the only thing moving is the eye of the raven."

Shan realized that Gendun was looking at Feng's wristwatch. Shan extended his arm.

"What do you call this?" the monk asked.

"A watch. A small clock." Shan removed it and handed it to him.

Gendun looked at it with wonder in his eyes and held it to his ear. He smiled and shook his head. "You Chinese," he grinned, and handed it back.

Tsomo left his side with a small reverent bow, and knelt beside the second monk, who still faced the altar.

"Even before the armies came from the north this place was known only to the few who needed to know," the old monk continued. "The Dalai Lama. The Panchen Lama. The Regent. It is said to be one of the caves of the great Guru Rinpoche," he said. "It is a world in itself. Usually those who come never leave. It was as you see it five hundred years ago. It will be like this five hundred years from now," he said with absolute confidence.

"I am sorry. But if we do not go back soldiers will come. We mean no harm."

"The tunnel can be sealed against searchers. It has been done in the past. For years at a time when necessary."

"He could teach us the way of the Tao," Tsomo interjected. "We could better understand the books of Lao Tze."

"Yes, Rinpoche. It would be wonderful to have such a teacher." Gendun turned to Shan. "Are you able to teach these things?"

Shan did not hear until he was asked the second time. The monk had called the boy Rinpoche, the term for a venerated lama, a reincarnated teacher. "An old abbot once said to me, 'I can recite the books. I can show you the ceremonies. But whether you learn them is up to you.' "

Tsomo gave a small laugh of victory, then rose and poured Shan more tea. "They say in parts of China it is impossible to separate the Tao from Buddha's way."

"When I lived in Beijing I visited a secret temple every day. On one side of the altar sat a figure of Lao Tze. On the other sat Buddha."

Tsomo's eyes grew round again. "Things always seem so far away from the top of a mountain. We have much to learn."

The moment was magical. No one spoke. The sound of the tsingha grew closer. A boy appeared, the small cymbals dangling in front of him. Behind him came two women, nuns, one carrying a tray with two covered bowls and the second a large pot of tea. They set the objects before the altar, and the monk who knelt there, his back still to Shan, began a ritual of blessing.

Shan knew he had heard the voice before, but there were so few monks he knew outside the 404th. Had he seen this man at Saskya? At Khartok, perhaps? He strained to see the man through the dim light as the nuns and monks spoke in turns, ceremonial words that Shan did not understand. When it was over the monk at the altar stood and straightened, then turned to face Shan.

"Are you ready?" he asked. It was Trinle.

They studied each other in silence. Shan felt strangely overwhelmed. For some reason he felt unable to ask how Trinle had spirited himself out of the camp, or why he had laboriously masqueraded as a pilgrim to reach Yerpa. Instead he followed them, Trinle and Tsomo and the two nuns, as they began climbing still another set of steep stairs, a narrow twisting passage worn, like the others, from centuries of use. After a minute's hard climb they reached a landing. The stairs continued ahead, but a dimly lit passage led to the left, toward the heart of the mountain. Along its sides several heavy wooden doors could be seen before the passage curved out of sight.

The group continued up the stairs, climbing in silence for at least five minutes. Twice Shan had to stop and lean against the wall, not from fatigue but from a strange overwhelming sense of passing through something, of straining against a barrier. He seemed to be hearing something but there were no sounds. He seemed to be seeing swarms of shadows shifting on the wall but there was only one steady lamp, carried far ahead. It was as though each step took them not toward another part of the mountain but toward another world. Each time he paused, Trinle was waiting with his serene smile.

They reached a landing with a thick wooden door, intricately carved with faces of protective demons and fastened with a heavy wrought-iron latch. Tsomo waited for them to gather on the landing and form a single-file procession, then opened the door, and led the way into the chamber with a low prayer.

There was no one inside. It was a sparse, square room, perhaps thirty feet to a side, furnished with one rough-hewn table and two chairs, a large iron brazier for holding coals, and several shelves of manuscripts. One wall was covered with an intricate mural of the life of Buddha. The opposite wall was of cedar planks, with a central wooden panel that seemed to match the door but it had no hinges or latches. It was held fast with huge hand-wrought bolts, fastened with nuts nearly the size of Shan's fist. On the floor beside it was one of the illuminated manuscripts, just below a black rectangular panel, perhaps ten inches high and twenty inches long.