‘I do not believe so. A different method was used to persuade the minds of men - an imp in a box rather than a human being thrown into history. And, though it is not clear, it seems that the makers of the amulet sought a different future from that described by al-Hafredi.’

Saladin struggled to absorb these dreadful ideas. He feared they were heretical, feared that even to speculate about such matters in the darkness of his own head might be to commit a sin.

But his mother briskly focused on the practicalities. ‘I see your point,’ she said to Thomas. ‘He who sent Ogodai’s imp may or may not have been our Weaver. But this does seem to prove that time can be spanned by an agent’s will, be he human or divine.’

‘Exactly.’ Thomas’s rheumy eyes were bright.

‘Well, it’s clear what we must do now. The veracity of the Codex is proved to be more than plausible.’

‘You never wrote back to your cousin Subh?’

‘I was never sure about that. After all Subh is a Muslim. Yet we need the Codex.’

‘You’re thinking of going to Seville yourself?’ Thomas asked cautiously.

‘Of course! I will dig up that mosque with my bare hands if needs must.’

‘But the armies of the Castilians are moving in on the city. Soon it may be besieged.’

‘All the more reason to move quickly, before some other chancer happens on the plans - or worse, Subh herself.’ Her eyes were cold. ‘I am sure now that this is our opportunity, our chance to revive our family’s prospects. We must take it without hesitation.’

Saladin gladly put aside the strange mysteries of the ever-changing tapestry of time, and grasped the essence of this new mission. ‘We are going to al-Andalus?’ He bunched his fists. ‘There are many Muslims there. I shall take the Cross!’

Joan stroked his cheek fondly. ‘That’s my boy.’ She stood. ‘We have much to do.’ Briskly, still talking, planning, scheming, she led them out of the room.

Thomas hurried after her. ‘Of course there is still the question of your enigma: Robert’s scrap of cipher, which may or may not have something to do with that phrase in Subh’s letter - Incendium Dei. As it happens I have heard of a young man who may be able to assist us, another Franciscan, a bright young philosopher at Oxford who is becoming notorious for his radical philosophies. His name is Roger Bacon . . .’

XVI

XVI

AD 1247

There was trouble at the pontoon bridge. A suspicious mob, a suspected spy, a near-riot - and the potential for real disaster for Seville, if its only bridge across the Guadalquivir were damaged.