‘Oh, of course I knew he slept with the whelp,’ Subh said. ‘Why do you think I didn’t question him? For fear he would blurt out the truth, or still worse profess some undying passion for the spread-legged little she-goat, and get himself put down.’

‘And you made an unnecessary enemy of Alfonso in the process.’

‘But he is already my enemy. You see, my son, I believe that to lie is wrong, but to allow a foolish boy to be stoned for a bit of careless lust is more wrong still.’

Ibrahim snapped, ‘Our family has lived in this den of decadence for too long. It has poisoned our blood, which must be cleansed!’ And he stalked off, unsatisfied.

So Peter was left alone with this woman, her languid form draped on a divan. Impossible fantasies ran through his head.

Subh sighed. ‘It is a trial to have a son whose soul is so much purer than mine. A reminder of the time when the holy Almohads ran all our lives, and the Almoravids before them.’

After the fall of Toledo a century and a half earlier, a bruised al-Andalus had fallen under the sway of cultists from across the strait, Almoravids and later Almohads, men of the desert with veiled faces who dressed in skins and stank of their camels, devout, disciplined and cruel. Attitudes hardened on both sides. The popes granted crusading indulgences to knights who fought in Spain, challenging another fundamentalism: that of the desert warriors.

‘The boy means well, of course. But he simply isn’t pragmatic. Are you pragmatic, scholar? Or are you religious?’

‘Not especially, though I do plenty of work for the religious houses, mostly the Franciscans. My ambition is to be a philosopher, for which I need to find patrons - like yourself, to whom I am eternally grateful.’ Peter’s career was a new sort, unimagined not so long before. Thanks to the injection of scholarship from the conquered regions of al-Andalus there had been an explosion of learning across Christendom, and all over Europe itinerant scholars like Peter were trying to make a living. ‘Of course,’ he went on, ‘the task of the scholar is to reconcile all our philosophy with the revealed truth of God.’ That was the official truth, but actually, it seemed to Peter, thanks to the Aristotelian studies of the Moorish scholars, across Christendom the close ties of devotion and scholarship were loosening.

Subh was still thinking about her son. ‘Ibrahim can’t see that the subtext of the little encounter today is my rivalry with Alfonso the Fat, and the long war he is waging to destroy me. That’s why he was trying to have poor Zawi put down - it’s nothing to do with the law, or what Zawi may or may not have actually done. It’s all to get at me.’

‘Why would he wish to do that?’