He was standing there looking up, sick to his stomach, knowing what was to come, when the key grated in the lock and the door was thrown open.

The little sergeant stood in the entrance, hands on hips, and smiled gently. Chavasse moved outside. The two privates were waiting, and they escorted him along the corridor. When the sergeant unlocked the door at the far end, a flurry of rain greeted them as they moved out into the night.

The sergeant walked through the darkness towards a truck parked by the guardroom and Chavasse waited in the centre of the courtyard with the two privates, the wind from the steppes like a bayonet in his back.

He wondered wearily what was going to happen next and then twin shafts of light from the truck picked him out of the night.

The sergeant returned, took out the automatic and made a sign to his two men, who withdrew into the darkness. Chavasse waited. For the moment, he and the sergeant seemed to be alone. He slid one foot forward cautiously, his eye on the automatic, and was deluged with ice-cold water from behind.

It hit with the force of a physical blow. He swung round and received another wave full in the face. The two soldiers stood laughing at him, buckets in their hands.

His whole body seemed to be gripped in a great vice which squeezed the air from his lungs as the wind cut through his soaked clothing, burning into his very flesh. He managed one faltering step towards them, his hands coming up, before the sergeant hit him a blow in the kidneys. As he went down, they moved in, boots and fists thudding into his defenceless body.

He was conscious of lying there in the centre of the yard, his face pillowed against the wet cobbles. He opened his eyes and the lights from the truck hurt them, and then he heard voices and was lifted from the ground and carried towards the lighted doorway.

It was with no sense of surprise that he found himself outside Colonel Li’s office, supported by the two privates. The sergeant knocked at the door, opened it and they went in.

They stood in front of the desk and for the second time that night Chavasse examined himself in the long, gold-framed mirror. He presented an extraordinary sight. Black hair was plastered across his high forehead. One eye was half-closed and the right side of his face was swollen and disfigured by a huge purple bruise. His mouth was smashed and bleeding and the front of his shirt was covered in blood.

Colonel Li looked up at him and sighed. “You are a very stubborn man, my friend, and to what purpose?” The whiskey bottle and glasses were still there, and he filled one and pushed it across the table. The soldiers lowered Chavasse into the chair and the sergeant held the glass to his lips.

Chavasse moaned in pain as the liquor burned into his raw flesh, but after a moment, a warm glow began to spread throughout his entire body and he felt a little better.

“You put on quite a show,” he croaked.

Li’s face creased in anger. “Do you imagine I enjoy this sort of thing?” he demanded. “Do you think I am a barbarian?” He pressed a buzzer on his desk. “Enough of this childish game of cat and mouse. I know who you are. I know all about you.”

The door opened and a young Chinese woman orderly entered with a file, which she placed on his desk. Chavasse noticed in a detached sort of way as she went out that her uniform fitted her like a glove, leather Russian boots setting off trim legs.

“It is all here,” Colonel Li said, holding up the file. “I’ve been in touch with Lhasa and they contacted our intelligence headquarters in Peking at once. Don’t you believe me?”

Chavasse shrugged. “That remains to be seen.”

Colonel Li flicked open the file and started to read.

“Paul Chavasse, born in Paris 1930, father French, mother English, so has dual nationality. Educated at Sorbonne and Cambridge and Harvard Universities. Ph.D. in modern languages. Lecturer at Cambridge University until 1955. Since then employed as an agent by the Bureau, a secret organization used by the British government in its constant underground war against the free Communist states.”

Chavasse was aware of no particular sense of shock that they knew so much. He was not even afraid. His entire body seemed to ache with pain and it was all he could do to keep his eyes open.

“You’ve certainly got one hell of a vivid imagination,” he said.

Colonel Li jumped to his feet angrily. “Why do you make me treat you like this? Is it the way for intelligent people to behave?” He moved round the desk and sat on the edge, a couple of feet away from Chavasse. When he spoke, his voice was gentle, as if he were trying to reason with a stubborn and wilful child. “Tell me what you are doing here, that’s all I want to know. Afterwards, you can have a doctor, a meal, a warm bed. Anything you desire.”

Everything was slipping away from Chavasse. To keep his eyes open was an effort and Li’s face seemed to swell to enormous proportions. He tried to open his mouth, but no sounds would come out.

The colonel moved close. “Tell me what I want to know, Chavasse. That’s all you have to do. I will take care of the rest, I promise you.”

Chavasse managed to spit in his face once before coloured lights exploded in his head and a great pool of darkness moved in on him.

Trudging along in the rain at the end of the column, Chavasse presented an extraordinary picture. His eyes had withdrawn into dark sockets, his hair was filthy and matted and his gaunt body was covered by an ancient and verminous sheepskin shuba.

His wrists were tied tightly together in front of him and the other end of the long rope was looped over the pommel of his guard’s high wooden saddle.

He was beginning to feel tired. The rain, blown against his face by the high wind, was icy cold and his stomach ached for food. He slowed a little, and immediately his guard tugged sharply on the rope, sending him stumbling forward onto his face.

The man screamed angrily in Chinese and Chavasse got to his feet painfully and started to hobble forward again. “All right, you bastard,” he shouted in English. “Keep your bloody hair on.”

He could see Colonel Li riding at the front of the column of thirty men, all mounted alike on wiry Tibetan horses, submachine guns across their backs, and he wondered again at the strange mixture of the old and the new that seemed so typical of the Chinese.

Despite the size of the area under his supervision, Colonel Li had only three jeeps and one truck, and when he made his rounds of the villages on the high plateau, where security was bad and he needed a strong escort, he was compelled to use cavalry.

The rain increased in force and Chavasse trudged on, feeling utterly miserable, the coldness seeping into his very bones.

He was perhaps at the lowest point in his life, and he knew that the fact that he admitted this even to himself was extremely dangerous. Colonel Li would have been surprised if he’d known how close he’d been to cracking. He raised his bound hands to wipe rain from his face and stumbled on.

For almost three weeks he had been beaten and humiliated in every conceivable way. Night after night, the bell in his cell had rung and the red light had flashed and sometimes they had come for him and sometimes they had not.

It was all part of a plan. All good sound psychology. Pavlov had started it with his dogs and the bell that sounded at mealtimes, had shown the world that gradually, by changing the order of things, you could produce a complete neurotic breakdown until a man became as broken in spirit as he was in body. Then and only then, the Party believed, could the process of rebirth begin. When the process was finished, the Party had another loyal and efficient zombie to swell its ranks.