‘And he spent the next eight years working to divine its secrets.’
‘Yes, and if he’d had the chance to work on it exclusively he might have done it, except the war got in the way. When he was recruited to the project to build Hitler’s nuclear bomb nobody would have given a damn about his obsession. From what my grandfather said in the journal he was forced to work in secret. That would have been at best disloyalty, maybe even treason. Walter Brohm was the original misunderstood genius.’
‘But he never gave up.’
‘Not Brohm. He was ruthless and ambitious and he saw in the Sun Stone an opportunity to carve his place in history. Ethical or moral dilemmas would never have entered his mind. Somehow he discovered what the material was and what it could be used for. It was his misfortune that by the time he had proof of its true potential Adolf Hitler had lost faith in his nuclear scientists.’
‘He also feared it. What does that tell us?’
Tenzin’s voice cut across the conversation. ‘It tells us the ancient priests were correct, Miss Grant. The Sun Stone has the potential to destroy the world.’
They stared at him.
‘Don’t you understand?’ the Tibetan went on. ‘In the Sun Stone lies the power of the sun. It is the material that fuels the stars. A source of infinite energy but also a source of infinite destruction. What has more potential than nuclear fission? What is the Holy Grail of science?’
Still they didn’t grasp what he was telling them.
‘Nuclear fusion. Controlled, limitless power from the joining of two atomic nuclei to form a heavier single nucleus. Fusion was first achieved in the nineteen thirties, but it has never been harnessed as a reliable source of nuclear energy. Whoever discovers a way to control it will have the economic power to hold the world to ransom. And the military power. Because with controlled nuclear fusion, comes the fusion bomb. Potentially a hundred times more powerful than a conventional nuclear bomb.’
‘If they know so much about nuclear fusion and have been working on it for so long why can’t they control it?’ Jamie asked.
‘Because they have never been able to discover the necessary catalyst that would give them both the high energy output they need and the control to contain it in a fusion reactor. I think this Walter Brohm believed he had discovered that catalyst.’
‘The Sun Stone?’
Tenzin nodded and his unsmiling face darkened, but Sarah interrupted before he could continue.
‘You said a fusion bomb could be a hundred times more powerful than anything we have now? That would be hugely destructive but it still wouldn’t destroy the world.’
‘That is correct, but it assumes that whoever builds the bomb understands what they are dealing with. A fusion bomb is basically uncontrolled nuclear fusion, a chain reaction that results in a thermonuclear explosion. What if there is no limit to that chain reaction? If the stone is truly the material that fuels the stars, it could be the catalyst not for an unlimited source of energy, but one that turns the earth into an inferno that burns for a hundred million years.’
For a few moments, they were each lost in their own vision of the end of the world. Eventually, Jamie said quietly, ‘Why did you bring us here?’
Tenzin’s eyes narrowed and his voice became solemn. ‘It seems to me that some force has linked you irrevocably to the Sun Stone. You were given the journal, which in turn provided you with Walter Brohm’s name. Now it has brought you here. You were sent to me for a reason. I think every step of your journey has been guided towards one outcome.’
‘And what is that outcome?’
‘You must return to Europe and continue your quest. I believe that only you can ensure the Sun Stone never falls into the hands of those whose greed or ambition or foolishness will destroy us all.’
Sarah stared at him, confusion plain in her eyes – along with something else that Jamie couldn’t read.
‘But how are we supposed to do that? You can’t place this responsibility on us. We’re just . . . just two ordinary people. We don’t have the strength, or the resources.’ She shook her head. ‘It’s too big. This is something for governments to deal with.’
‘On the contrary, Miss Grant.’ Tenzin’s face was grave. ‘It is governments you must beware. Governments like the one that has invaded and oppressed my country would give anything and do anything to lay their hands on the Sun Stone and release its power. Communism has no soul, just as fascism had none, but what about capitalism? Do you think the Americans would be different? In nineteen seventy-one Richard Nixon betrayed my people for a handshake and a smile from Mao Zedong; are we to expect any better from the current president?’