The monk bent over to the hole and murmured something in a low voice. Then he turned to listen. Minutes passed, and Pendergast heard the faintest whisper from within. The monk straightened up, apparently satisfied, and gestured for Pendergast to step close. Pendergast did as requested, watching the stone slip back into position, guided by an unseen hand.

All of a sudden, a deep scraping sound seemed to come from within the rock next to the stone cell, and a seam opened up. It enlarged to become a stone door, which grated open on some unseen mechanism. A peculiar scent of some unknown incense wafted from within. The monk held out his hand in a gesture for Pendergast to enter, and when the agent had passed over the threshold, the door slid shut. The monk had not followed—Pendergast was alone.

Another monk appeared out of the gloom, holding a guttering candle. During the past seven weeks at Gsalrig Chongg, as well as in his previous visits, Pendergast had come to know the faces of all the monks—and yet this one was new. He realized he had just entered the inner monastery, whispered about but never confirmed—the hidden sanctum sanctorum. Such access—which, he’d understood, was absolutely forbidden—was apparently guarded by the immured anchorite. This was a monastery within the monastery, in which a half dozen cloistered monks passed their entire lives in the profoundest meditation and unceasing mental study, never seeing the outside world or even coming in direct contact with the monks of the outer monastery, guarded by the unseen anchorite. They had so withdrawn from the world, Pendergast once heard it said, that the light of the sun, should it fall upon their skin, would kill them.

He followed the strange monk down a narrow corridor, leading into the deepest parts of the monastic complex. The passages became rougher and he realized that they were tunnels cut out of the living rock itself: tunnels that had been plastered and frescoed a thousand years before, their paintings now almost obliterated by smoke, humidity, and time. The passage turned, and turned again, passing small stone cells containing Buddhas or thangka paintings, illuminated by candles and drifting with incense. They passed no one, saw no one—the warren of windowless rooms and tunnels felt hollow, damp, and deserted.

Finally, after what felt like an endless journey, they came to another door, this one bound in bands of oiled iron, riveted into thick plates. Another key was brandished, and with some effort the door was unlocked and opened.

The room beyond was small and dim, illuminated by a single butter lamp. The walls were lined in ancient, hand-rubbed wood, meticulously inlaid. Fragrant smoke drifted in the air, pungent and resinous. It took Pendergast’s eyes a moment to adjust to the extraordinary fact that the chamber was packed full of treasure. Against the far wall sat dozens of caskets in heavy repoussé gold, their lids tightly locked; next to them stood stacks of leather bags, some of which had rotted and split, spilling their contents of heavy gold coins—everything from old English sovereigns and Greek staters to heavy gold mughals. Small wooden kegs were stacked around them, the staves swollen and rotted, spilling out raw and cut rubies, emeralds, sapphires, diamonds, turquoises, tourmalines, and peridots. Others seemed filled with small gold bars and oval Japanese kobans.

The wall to his right contained a different kind of treasure: shawms and kangling horns made of ebony, ivory, and gold, and encrusted with gems; dorje bells of silver and electrum; human skullcaps trimmed in precious metals and glowing with turquoise and coral inlay. In another area stood a crowd of statues in gold and silver, one adorned with hundreds of star sapphires; nearby, nestled in wooden crates and straw, he could see translucent bowls, figures, and plaques of the finest jade.

And to his immediate left, the greatest treasure of all: hundreds of cubbyholes stuffed with dusty scrolls, rolled thangkas, and bundles of parchment and vellum tied in silk cords.

So astonishing was the display of treasure that it took Pendergast a moment to realize a human being was sitting, cross-legged, on a cushion in the near corner.

The monk who had brought him now bowed, hands together, and withdrew, the iron door clanging behind him, the lock turning. The cross-legged monk gestured toward a cushion beside him. “Please sit down,” he said in English.

Pendergast bowed and seated himself. “A most remarkable room,” he replied. He paused a moment. “And a most unusual incense.”

“We are the guardians of the monastery’s treasures—the gold and silver and all other transitory things the world considers wealth.” The man spoke in a measured and elegant English, with an Oxbridge accent. “We are also stewards of the library and the religious paintings. The ‘incense’ you note is the resin of thedorzhan-qing plant—burned ceaselessly to keep the worms at bay—ravenous woodworms indigenous to the high Himalayas that seek to destroy everything in this room made of wood, paper, or silk.”

Pendergast nodded, taking the opportunity to examine the monk more closely. He was old, but wiry and astonishingly fit. His red-and- saffron robes were tightly wound, and his head was shaven. His feet were bare and almost black with dirt. His eyes gleamed in a smooth, ageless face that radiated intelligence, anxiousness, and grave concern.

“No doubt you’re wondering who I am, and why I have asked you to come,” the monk said. “I am Thubten. Welcome, Mr. Pendergast.”

“Lama Thubten?”

“We have no distinguishing titles here in the inner temple.” The monk leaned toward him, peering closely at his face. “I understand that your business in life is to—I am not sure how to put it—to pry into the affairs of others, to put right what has been wronged? To solve riddles, shine light onto mystery and darkness?”

“I have never heard it put quite that way. But yes, you’re correct.”

The monk sat back, relief evident on his face. “That is good. I feared perhaps I was mistaken.” Then his voice fell almost to a whisper. “There is a riddle here.”

There was a long silence. Then Pendergast said, “Go on.”

“The abbot cannot speak of this matter directly. That is why they have asked me to do so. Yet even though the situation is dire, I find it . . . difficult to talk about. ”

“You have all been kind to me and my ward,” said Pendergast. “I welcome the opportunity to do something in return—if I can.”

“Thank you. The story I am about to tell you involves revealing some details of a secret nature.”

“You can count on my discretion.”

“First I will tell you a little of myself. I was born in the remote hill country of Lake Manosawar in western Tibet. I was an only child, and my parents were killed in an avalanche before my first birthday. A pair of English naturalists—a husband-and-wife team doing an extensive survey of Manchuria, Nepal, and Tibet—took pity on such a young orphan and informally adopted me. For ten years I stayed with them as they traveled the wilds, observing, sketching, and taking notes. Then one night a roving band of soldiers came upon our tent. They shot both the man and the woman, and burned them with all their possessions. I alone escaped.

“Losing two sets of parents—you can imagine my feelings. My lonely wanderings took me here, to Gsalrig Chongg. In time I took a vow and entered the inner monastery. We devote our lives to extreme mental and physical training. We occupy ourselves with the deepest, the most profound, and the most enigmatic aspects of existence. In your study of Chongg Ran, you have touched upon some of the truths that we plumb to an infinitely greater depth.”