Within half an hour, they seemed lost in a landscape so barren, it might have been the moon. Great snow-covered peaks towered on every side and Kerensky, handling the plane with genius, moved through a maze that seemed to have no ending. Beyond the peaks, the stars were like diamond chips set in a black velvet cushion, brighter than Chavasse had ever known.

On several occasions, they dropped in air pockets. Once, as they curved from one pass into another, Chavasse could have sworn that their right wingtip touched the rock wall, but they flew on, Kerensky’s great hands steady on the controls.

Suddenly, they skimmed over the shoulder of a mountain and three hundred feet below, a lake glittered in the moonlight.

“Pangong Tso!” Joro shouted above the roar of the engine.

The great pass lifted to meet them. Kerensky eased back the stick slightly, but as the plane rose, so did the frozen earth beneath.

Chavasse held his breath and waited for the crash, but it didn’t come. With fifty feet to spare, they were over the hump and flashing between rock walls on one side and a glacier on the other.

Beneath them, a dark plateau rolled away into the distance as far as the eye could see. Kerensky turned and smiled in the dim light thrown out by the instrument panel. “Thought you might like to know we’re now over Tibet,” he shouted. “I’m altering course slightly to bypass Rudok. No sense in advertising.”

The plane banked sharply to the east and then resumed level flight. The view was spectacular as the rolling steppes stretched away to the horizon. Here and there, hollows and valleys lay dark and forbidding, thrown into relief by the white moonlight, which picked out the higher stretches of ground.

And then a lake appeared, and a few moments later, another. Joro tapped Kerensky on the shoulder and the Pole nodded and took the plane down.

The sand flat at the eastern end of the lake gleamed white in the moonlight and Kerensky circled once and started to put the plane’s nose down for a landing. Suddenly he banked sharply and started to climb.

“What’s wrong?” Chavasse cried.

“Thought I saw a light down there,” Kerensky said. “Just over the hill from the shore. I’ll go down and take a look.”

He took the plane round once more, but there was no sign of a light. “What do you think?” he said over his shoulder.

Chavasse looked enquiringly at Joro and the Tibetan shrugged. “If there was a light, it could only have been a herdsman’s fire. Chinese soldiers wouldn’t dare to spend a night in the open in this area.”

“That settles it.” Chavasse tapped Kerensky on the shoulder. “Put her down.”

Kerenksy nodded and circled the lake once more before turning into the wind for a perfect landing on the shore. Chavasse didn’t waste any time. As the plane taxied to a halt, he opened the door, jumped to the ground and turned to help Joro down with the guns and ammunition.

Sand, whipped up by the propeller, enveloped him in a cloud of stinging particles, but within a few moments the boxes were on the ground and Joro was beside him.

Kerenksy reached over to close the door. “One week from now, same time, same place,” he shouted above the roar of the engine. “And be here on time. I don’t want to hang around.”

Chavasse and Joro quickly dragged the boxes out of the way and stood back and watched as Kerenksy taxied along to the other end of the strand and turned into the wind.

As he moved forward, the engine note deepened, and a few moments later the plane banked away across the lake, gaining height all the time, and disappeared towards the northwest.

His ears still ringing with the sound of the plane’s engine, Chavasse turned to Joro. “We’d better find somewhere to dump this little lot until your pals from Yalung Gompa can pick it up.”

He moved across the sand towards a narrow gully which cut into the side of the hill about forty yards away. Strange how the sound of the engine still rang in his ears, but the gully looked just the place.

He turned to call Joro and a jeep appeared on the crest of the hill as if by magic.

In that first frozen moment of panic he was aware of the peak caps of the soldiers and the long ugly barrel of the machine gun mounted on a swivel, and then he was running into the open, one hand reaching for his Walther.

“Look out, Joro,” he cried in English.

The heavy barrel of the machine gun was already swinging towards the Tibetan, and ribbons of fire stabbed through the night, kicking up the sand in great fountains.

Joro flung himself sideways, rolling desperately, and Chavasse dropped to one knee and got off a couple of shots to draw their fire.

Joro scrambled to his feet and disappeared into the shelter of a jumbled mass of boulders at the water’s edge as the barrel of the machine gun turned towards Chavasse. He retreated into the mouth of the gully, flinging himself flat on his face as bullets hammered the rocks beside him.

A splinter cut his cheek and when he got to his feet and tried to move farther into the sheltering darkness, a bullet sliced across his left shoulder. He hugged the earth again and waited and when the bullets at last stopped coming, the silence was even harder to bear. He cautiously scrambled to his feet again, and immediately there was a muffled explosion and the gully was bathed in a hard white light.

He looked up at the descending flare and waited, because there was no place to run to. After a while, stones rattled down and two Chinese soldiers appeared on the rim of the gully, burp guns ready. As he raised the Walther to fire, a third man appeared between them.

He stood on the edge of the gully, a slight smile on his face, so close that Chavasse could see the feather in his Tyrolean hat and the fur collar of his hunting jacket.

“Don’t be a damned fool,” the man said calmly in English. “That thing’s going to do you no good at all.”

Chavasse looked up at him in astonishment and then, in spite of the pain in his shoulder, he laughed. It had, after all, been a night for surprises.

“You know, I think you’ve got something there,” he said, and tossed the Walther across and waited for them to come for him.

The wind from the steppes moved down into the hollow, touching Chavasse with icy fingers. He shivered and pulled his sheepskin shuba up about his face with one hand.

The pain in his shoulder had lapsed into a slow, dull ache, the raw flesh anesthetized by the bitter cold, and he had a splitting headache and a slight feeling of nausea. Probably something to do with the fact that he hadn’t had sufficient time to become acclimatised to the altitude.

He sat with his back propped against one of the wheels of the jeep and a few feet away, a spirit stove flared in the wind in front of a small pup tent. The two Chinese soldiers crouched beside it. One of them held his burp gun across his knees and smoked a cigarette while the other heated coffee in an aluminum pan.

Chavasse wondered about Joro. At least he’d managed to get away in one piece, so something had been salvaged from the mess, but for the moment, he could look for no help in that direction. Without arms and alone, the Tibetan could accomplish nothing. If he managed to contact some of his men, that would be another story.

The tent flap opened and the man in the Tyrolean hat and hunting jacket crawled out carrying a first-aid box.

He crouched down beside Chavasse and grinned sympathetically. “How do you feel?”

Chavasse shrugged. “I’ll survive, if that’s what you mean.”

The man produced a packet of cigarettes. “Try one of these. It might help.”

He was about thirty-five, tall and well-built, and the match flared in his cupped hands to reveal a strong, sensitive face and mobile mouth.