“To see me?” Hoffner said, and a look of incredulity appeared on his face. “But that is impossible. For one thing, the Chinese would never let me go.”

“Never mind about that for the moment,” Chavasse said. “If it could be managed, would you be willing to try? I rather got the impression from our earlier conversation that you approved of what’s been happening around here.”

Hoffner chuckled. “What on earth would you have expected me to say to a foreign correspondent of Pravda? Oh, Colonel Li has shown me a great deal of personal kindness, I can’t deny that, and he really has done everything possible to ensure that I receive all the drugs and medical supplies I need for the clinic.”

“I must say he seems remarkably philanthropic for a case-hardened Communist,” Chavasse said.

“It’s quite simple.” Hoffner smiled gently. “I have succeeded in building up a certain standing in this country over the years, and the people have come to trust me. The reason that my clinic has not been closed down is that the Communists believe I not only approve of them, but that I am willing to cooperate with them.”

“And the only way to refute this would be to refuse to work at the clinic, which would mean no medical centre for the Tibetans,” Chavasse said. “Colonel Li certainly knows how to put people into a cleft stick.”

“A facility he seems to share with most good Communists,” Hoffner said.

“Which brings me back to my first question,” Chavasse told him. “If I could get you out, would you be willing to leave?”

Hoffner tapped ash from his pipe into the hearth and then started to refill it from an old leather pouch, a slight frown on his face.

After a while, he said, “Young man, I am seventy-four years of age. I’m also in rather poor health, which is no good augury for the future. I may not approve of the Communist regime as practised in this country, but they do at least allow me to continue to give medical treatment to a rather backward people who would otherwise have to manage without it. It would seem to me that my duty lies in continuing to offer it to them for the few years that remain to me.”

“And what if I said you were needed on the outside more?” Chavasse said. “A great deal more?”

“I think it would help if you were to explain,” Hoffner told him, and smiled suddenly. “It would also help if I knew your real name.”

Chavasse shrugged. “It won’t mean anything to you, but I don’t see why not. It’s Chavasse, Paul Chavasse.”

“Ah, French,” Hoffner said. “How interesting, but I hope you don’t mind if we continue to use English for the moment. It makes a delightful change, I assure you.”

Chavasse lit a cigarette and leaned forward. “Many years ago you prepared a thesis for your doctorate in mathematics in which you proved theoretically that energy is space locked up in a certain pattern.”

Hoffner frowned. “But how did you know this?”

“You mentioned it to Craig in your letter. You also went on to say that you’ve now carried things a stage further – you’ve now proved that space itself can be changed into an energy field.”

“But I don’t understand,” Hoffner said in surprise. “Why is Edwin Craig so concerned about what, at best, is an interesting new mathematical concept? All entirely theoretical, I assure you.”

“It was, until the Russians sent a man called Gagarin into space to orbit the world,” Chavasse told him. “And then sent another to prove it was no fluke.”

Hoffner had been in the act of applying a lighted taper to the bowl of his pipe. He paused, and something glowed deep in his dark eyes. “It would be stupid of me to imagine that you are joking?”

Chavasse nodded. “The Americans have already emulated the performance. They’re trailing slightly, but catching up fast. I wouldn’t like to say who’ll be first on the moon. One thing Iam sure of. It won’t be the Chinese. They aren’t even in the race.”

“Which explains why here in Changu we have been kept in the dark.” Hoffner jumped to his feet and paced restlessly across to the window and turned. “For once in my life I feel really angry. Not only as a scientist, but as a human being. To think that while here one day has followed the next like any other, outside, in the world, man has already taken the first steps on the greatest adventure ever known.”

He came back to his chair and sat down. His face had become animated and flushed and there was a sparkle in his eyes. “Tell me about it,” he demanded. “Everything you know. What kind of propulsion are they using, for example?”

“Both solid and liquid fuels,” Chavasse told him. “Multistage rockets, of course.”

Hoffner shook his head. “But this is primitive, my friend. To take a satellite to the edge of space is one thing, but to reach the moon or beyond…”

“That’s where you come in,” Chavasse explained. “The Russians have been working for years on an ionic rocket drive using energy emitted by stars as the motive force. They’re years ahead of the West. If they keep that lead, it means eventual world domination by Communism.”

“And Craig thinks that my new theory can take that lead away from them?”

Chavasse nodded. “I’m no scientist, but he seems to think that with your discovery, we could produce an energy drive for our rockets from space itself. Is he right?”

Hoffner nodded soberly. “Speeds greater than we have ever dreamed of, something essential if the universe is ever to be fully explored.”

There was a moment of silence before Chavasse said quietly, “I know your patients are important to you, but you must see now why it’s essential that you return to the outside world.”

Hoffner sighed heavily and emptied his pipe. “I do indeed.” For a moment longer, he stared into the fire, and then he looked up and smiled. “I don’t know how on earth you intend to manage it, young man, but when do we leave?” He frowned suddenly. “And what about Katya? I can’t leave her behind.”

“Do you really think she’d come?” Chavasse asked in surprise.

Hoffner nodded. “She is anything but a political animal, and she has no ties here or in Russia, no family.”

Chavasse sighed. “It could be awkward. Let me think about it, but for God’s sake don’t tell her a thing. What she doesn’t know can’t be squeezed out of her. That’s always important in an affair like this, in case anything goes wrong. There’s no need to rush things. We’ve got five days before my plane returns. The only real problem will be in finding a way of getting you out of Changu.”

He had been subconsciously aware of a slight draught on his right cheek for several moments.

He turned and found Katya standing just inside the door, holding a tray on which stood a glass of hot milk.

He wondered how long she’d been standing there and, more important, just how much she had heard, but she gave him no sign. She moved forward, handed the glass of milk to Hoffner and said calmly in Russian, “Time for bed, Doctor. It’s been a long day.”

Hoffner sighed, took a sip of milk and made a face. “You see, my friend,” he told Chavasse. “The wheel has come full circle. Like a schoolboy, I do as I am told.”

“I’m sure Comrade Stranoff knows what’s best for you,” Chavasse said.

She smiled down at him enigmatically. “But of course, Comrade Kurbsky. In everything.”

For a moment, there was something strange in her eyes. Only briefly, but it told him what he wanted to know before she turned, crossed to the door and went out again.