Harry had had enough of the grand sweep of history. ‘Well, all I want is to get back to my own life,’ he said firmly. ‘I’m thirty-six years old now, brother, and feeling it. I have spent too long on the past; I want to think of the future. If I can find a wife, have some children—’

‘Good for you.’

‘And I want to get back to trade. If there’s profit to be made from this adventure, I want a share in generating it - and spending it. The Spanish aren’t the only explorers. I have been corresponding with an Italian adventurer called Jacobo Caboto who is going to approach King Henry with a proposal to try to find a route to Asia through the northern seas, following in the wake of the long-dead Vikings.’

Geoffrey grunted. ‘Perhaps you will find Vinland, if not China.’

‘And what next for you, Geoffrey?’

Geoffrey thought, tugging at his lip. ‘I have been contemplating this muddy business we have been involved in. I want to do something about it. We have been at the focus of a battle between two time-meddling agents, the Weaver who fed the designs of the Engines of God back to Aethelred and Aethelmaer, and the Witness who spoke to Eadgyth.

‘And there is evidence of other tampering, Harry. Your remote ancestor Sihtric, dead four centuries, made marginal notes on his copy of the Engine Codex. He believed he had found evidence that the Weaver, or another agent, tried to avert the course of the Norman Conquest of England. And even earlier, in the deep and ancient days when the Romans ruled Britain, another meddler, or the same one, tried to arrange the assassination of the Emperor Constantine. I have tried to map all this.’

He produced a parchment on which he had scribbled a kind of tapestry. He explained that the long warp threads were the true course of history, the wefts the deflections of history, or attempted deflections - he had found no less than six of them, from the failed assassination of Constantine to the amulet of Bohemond which resulted in the murder of the Mongol Khan.

Harry gaped. ‘That’s astonishing.’

‘Yet it seems to be true. But after all this meddling, what is left? What is true, what is right? What should our destiny be? The tapestry of time, rent apart and rewoven over and over, has become a shabby, worthless rag.’

‘And you’re thinking of doing something about it?’

Geoffrey’s gaze was distant. ‘What if I could speak to a Weaver of my own, off in some future time? I don’t know how - perhaps I will write and speak and have my words printed up in a thousand copies, so that they never die. Or perhaps I will simply take my testament to my grave, and one day, when my body is exhumed, my words will rise with me.’

‘What will you say?’