Once more she glanced outside. Solo and Illya were on their feet, guns drawn. The rumble increased.

Mei gripped the door frame tensely, watching.

After a long moment she relaxed.

"They are going on."

"It is only a temporary respite," said Ah Lan. "A terrible journey awaits us tomorrow."

Three

In single file, the four of them struggled upward through knee-deep snow.

They had departed from the crossroads at first light, encountering no more Chinese soldiers en route. The first few hours hadn't been difficult. The terrain was rocky, sloping upward, but footing was sure. Gradually, however, conditions grew worse as they climbed.

Light veils of cloud began to drift around them. The clouds obscured the pale sun. The last vegetation vanished when they reached the snow line. The snow began to deepen and the wind intensified. For the past hour the snow had been up to their knees. And there seemed to be little immediate prospect of relief. Up they went, up and higher.

On either hand rose immense and stark walls of rock, their tops lost in clouds of whirling, billowing snow. Solo realized that they must be in the pass proper. But how long it would take them to reach the crest, he didn't know. He stumbled ahead, kicking up great gouts of the white stuff.

The wind screamed.

The snow began to take on a grayish cast. Solo wondered if his eyes were going bad. He had a recurring vision. He saw a sumptuous, oversized bed in a tropical resort hotel. Angrily he shook his head to drive the vision out. If he fell prey to that sort of hallucination, he was in trouble. It would be all too easy to lie down in the snow and forget everything.

Blinking again, Solo halted this side of a deep drift. He peered around. No sane man would believe the time of day was noon.

The vista before him was one of unrelieved white-flecked gloom. The wind howled so loudly the effect on the ears was like sitting on top of an operating fire siren. Solo realized abruptly that he had lost sight of Mei's fur-clad figure ahead.

He could see nothing except snow and the sheer walls on either hand.

He lifted his fur-wrapped right arm and tore the rags from his mouth. The snow struck his bare face with little needles of pain. He shouted the name of his companions. Only the howling wind answered.

With much twisting and writhing, he managed to get his hand beneath the various layers of snow clothing which Ah Lan had provided. He located the butt of his pistol within the folds of his lama robe. He pulled the pistol out into the snowy air and fired it three times.

"That'll bring them." He stuffed the gun away and pulled on his mitten.

Soon, Napoleon Solo concluded that he had committed a grievous error in judgment. Instead of the shouts of his friends coming to his rescue, he heard a sinister rumbling overhead.

The rumbling grew louder. Solo looked up, shielded his eyes. His gut tightened. The echoes of the shots bouncing back and forth between the rock walls had dislodged a small avalanche. Even as Solo stared, practically hypnotized by the awful sight, several thousand tons of the stuff came hurtling downward toward him.

Solo threw himself backwards. An instant later a huge, wet mass slammed down onto him like a white sledgehammer. The world rocked and roared.

Solo clawed and sputtered. Snow surrounded him, buried him. He fought upward like a swimmer. The snow pressed against his face, weighed down on the back of his neck.

With a herculean lunge, he fought to its surface.

A few large chunks of snow crashed down like oversized projectiles. One whizzed past Solo by a margin of about two feet. The force of it dug a deep, deep hole in the drift holding him prisoner.

Suddenly a furry figure appeared, crashing and lurching toward him. Two others followed. More gigantic snowballs cascaded down. The rocky walls of the pass shook.

Illya, the old Tibetan and his daughter reached Solo, knelt, seized his arms. Illya shoved him to his feet. Ah Lan dragged Mei toward the far wall of the pass, crying:

"Seek shelter, quickly! The avalanche is coming!"

Like people demented, they ran, floundered, leaped, and crawled as best they could. They reached the pass wall and huddled against it as the air filled with thousands of great balls of snow. The balls suddenly solidified into a curtain of the stuff. Solo wrapped his arms around the trembling girl and pulled her head down against his chest.

Presently the white cascade stopped. The old, less alarming shriek of the blizzard returned. Ah Lan raised his seamed face and pointed. "The gods in their infinite

mercy chose to protect us."

The others looked up. A triangular ledge jutting from the rock above their heads was all that had saved them from being buried alive.

All of them were panting an floundering at an abysmally slow pace when Solo suddenly realized that the going had become easier.

He shouted, "I think the snow's sloping downward. Yes, look. The clouds have thinned up ahead. I see sunlight."

Ah Lan managed a smile. The worst is behind."

Their speed increased as the snow became less and less deep. Now it was possible to see the slate walls of the pass in sharper detail. The wind dropped off. Only a few snowflakes danced before their faces. And a breeze from a different quarter seemed to be shredding the misty gloom which had enveloped them for so many hours.

Solo and Mei tramped faster, Illya and the old Tibetan close behind. Shortly blazing sunlight struck their faces. The sky overhead spread frosty blue and cloudless. Illya tossed away the rags around his parka hood as Solo circled some tumbled boulders and

pulled up short, gasping.

"Now I believe it," he said as the others crowded wearily up behind him. "There really is a Shangri-La."

Four

The foothills of the peaks dropped gently away toward sparkling green rice fields. A bird sang somewhere. Trees bent in a gentle wind. Wind-ruffled water gleamed. Directly below them was some sort of orchard, the fruit-laden trees standing in neat rows. It was an altogether idyllic and beautiful scene, marred only by several structures far out in the center of the valley.

These were low, black-painted buildings of stone. Several had no windows. Others had a few, and resembled barracks. Behind this complex an airstrip bisected the lush landscape like a raw concrete wound.

"They don't take siestas in Tibet," Illya said. "Where is everyone?"

"I believe many of the laboratories and facilities are underground, Mr. Solo," Mei said. She had thrown back her parka. Her dark hair shone like a sleek bird's wing.

The look she gave Solo was warm and worshipful. Illya made a resigned face.

Grumpily Illya climbed out of his two sets of coats and trousers. He stowed them behind a rock and adjusted his priest's robe and headgear. In a moment the transformation of the whole group was complete. They were now two priests with darkly-hued faces and slanted eyes, plus an elderly farmer and his daughter.

They crouched behind rocks while Solo surveyed the valley with field glasses which he had taken from his robe. "That big building close to the far end of the airstrip looks like a hangar. But I still don't see a single human being anyplace."

"It will be too dangerous to attempt to approach during daylight," Ah Lan said.

Solo nodded. "But there's enough cover for us to go as far as that orchard. From there we can watch till nightfall."

Ah Lan peered toward the barracks-like structures. "Surely our entrance to the valley cannot have gone unobserved. Yet it appears that it did. As my daughter told you, much of the facility is believed to be built under the earth. Perhaps THRUSH feels itself so secure that guards are unnecessary.