Rory fell silent. Ben stared at him.

'Oh, come now. If you don't tell him, I can – and will.' She patted her briefcase.

'Very well,' Rory blurted. 'It was Nicea.'

Ben was bewildered. 'Nicea?'

Julia smiled. 'You're clearly not as intimately acquainted with Christian history as your little friend here, Ben. Nicea, 325 AD. Where the Emperor Constantine convened his great Church council.'

'Constantine!' Rory spat. 'It was all his fault!'

'Ah, the Romans,' Julia said. 'They were Aryans, you know, without a doubt. Hitler has the scholarship to prove it… Before Constantine,' she sneered, 'Jesus was a god of the slaves. By establishing the Church as the state religion of Rome, Constantine saved Christianity for the future.'

'Only by making it into a reflection of Rome itself! And it is that Roman autocracy and intolerance that has been at the root of the evil done in Christ's name ever since.'

'And so you had the temerity to cook up a plan. Didn't you? A scheme to use your Loom of time to unpick a few threads of history.'

'You told me none of this,' Ben accused Rory.

'Of course not,' he said miserably, still avoiding his eyes. 'Because you would have stopped me.'

'He worked out a message to send to the past,' Julia said brightly. 'A sort of retrospective prophecy, yes? You meant to send it to the age of Emperor Claudius, I gather, and his invasion of Britain. It was going to contain news about the future – and a little comical nonsense about democracy-'

'The republican age was the best of Rome,' Rory said defiantly. 'It inspired America centuries later. I wanted to give them hope.'

'Who?' Ben demanded.

'You know how it works, Ben. We can't target an individual in the past. We can only broadcast. And hope there are minds as receptive as yours – natural radio receivers, waiting to pick up news from the future.'

Julia said, 'You put in the prophetic stuff as a sort of lure, didn't you, Rory? You sent it back beyond Claudius to the year of Christ's birth, to catch the attention of the early Christians. You hoped to snag your dupe in the past by giving him a bit of foreknowledge that could make him powerful or rich, for instance about the building of Hadrian's wall. And you hoped that that power would be used as you intended: to fulfil your ultimate command.'

'To do what?' Ben asked.

Julia grinned. 'Why, to kill the Emperor Constantine!'

Ben found himself on the edge of panic. 'Rory – we discussed the dangers – what gives you the right to make such choices?'

'What gives us the right not to use such a gift?'

Ben thought fast. 'But this is just fantasy. Just talk. For Constantine was not cut down before Nicea, was he? And the Church was not restored to some state of innocence. The Pope still sits in Rome.'

'Rory failed,' Julia said.

'Well, I can't deny that,' Rory said.

'But he made the attempt, Ben.'

'That's impossible.'

'No.' She smiled. 'I have proof.'

Rory's eyes narrowed. 'What do you mean by that?'

'The Party has a rather good research institution. It's called the Ahnenerbe – it reports to Himmler, you know. Some quite innovative research into racial origins. I wrote to them…' She opened her briefcase and extracted a battered volume. It was a history of Rome.

Her Nazi scholars had not been able to retrieve Rory's testament in full. But elements of it had been recorded in an autobiographical work by the Emperor Claudius. That work too was lost, but there were references to it in other histories, from which, with a little care and some guesswork, some of Rory's lines had been reconstructed. She passed her book to Ben, opening it at a marked page. He read in disbelief, the text pale on old, yellowed paper:

Remember this: We hold these truths self-evident to be -

I say to you that all men are created equal, free

Rights inalienable assured by the Maker's attribute

Endowed with Life and Liberty and Happiness' pursuit.

O child! thou tapestried in time, strike home! Strike at the root!…

'By all that's holy,' Ben said, his heart hammering.

Julia smiled. 'Life, liberty and the pursuit of happiness. How delightfully gauche!'

'It seems I did it,' Rory said, his own eyes wide. 'These are my own words, cooked up in 1940, transmitted through the centuries, and now written down in this battered old history book. I never saw the proof before. I failed in my plan – Constantine survived – but the Loom works.' He laughed, but it was a brittle sound.

'You could not have done this,' Ben said weakly. 'I am an integral part of the Loom – my supposed precognition-'

'He drugged you,' Julia said simply. 'Drugged you, and used you in your sleep. Would you have stopped him?'

'Of course I would.'

'Why? Because you're a fan of Constantine?'

'No.' He looked at Rory with gathering horror. 'Because I have come to believe that the Loom, if ever operated, is a monstrous danger. The Loom is a weapon that destroys history, not creates it!'

'Yet it works,' Rory said flatly.

'Yes,' Julia said. 'Hitler despises Christianity, you know. He says it amounts to the systematic cultivation of failure. I think he'll rather approve of your attempts to destabilise the faith, Rory.'

'What do you mean by that?' Rory snapped.

'I really believe the Ahnenerbe is the place to carry forward this project of yours, don't you think? With proper funding and some decent researchers – not some half-trained Irish monkey and a mixed-up Jewish dreamer – with a better calculating machine than the antiquated gadget at MIT-'

'You want to give a time machine to the Nazis?' Ben felt weak. 'Oh, that's a good plan.'

Rory asked, 'So you're planning to support Hitler?'

Julia shrugged. 'What do you care? Ireland is neutral in the war.'

'But your own country isn't.' Rory stood up. 'You English aristocrats are all the same. You and your bloody empire. Now it's better Hitler than a Labour government, eh? Well, you're not going to give my work to that gang of thugs.' He raised a fist and closed on her.

It happened in an instant. From somewhere Julia produced a gun. Ben had time to notice how small it was, how exquisitely made, how expensive it looked. She raised the pretty, silver-plated pistol. She shot Rory in the heart. Rory looked surprised, and he stared down at the bloody mess of his chest. He shuddered; he crumpled and fell.

'Well, that's a bit unfortunate,' Julia said. 'We have made rather a mess of the apartment, haven't we? I don't need him. No doubt everything's here among these books and papers. But, of course, I need you. She turned to Ben and smiled. 'You and your dreams.'

'You want to hand me over to your Ahnenerbe. To the Germans.'

'They're here already. All around the building.'

'They'll love you in Nazi Germany,' he said.

'Oh, they will. They do! Now, will you come with me quietly or-'

He was still holding the heavy history book. He slammed it as hard as he could against her temple. He moved suddenly, giving her no notice at all. She fell, even more quickly than Rory, her gun spilling from her hand.

Ben looked at the mess, Julia sprawled across Rory's legs, the silver gun on the floor. He ought to destroy any evidence of their work. Take the gun. Kill Julia.

He knew he could not. His head was filled with flight, nothing more. All he wanted was to run until he could run no further, out of Princeton, out of America – all the way to England, perhaps, where at least he could be sure there were no Nazis.

But first he had to survive this day, uncaptured. He headed for the door, watching for Julia's German supporters.