Orm didn't smile. 'And so, in this atmosphere of indulgence, your soul softened.'

'I was seduced,' Sihtric said. 'The first to come to me was a boy, slim, dark, with eyes like a deer's. He was a student. As we worked he sat close to me, he brought me presents – flowers in glass bowls, that sort of thing. I didn't really notice, to tell the truth; the work was everything. Then one night he slid into my bed. I was half asleep – I thought it was a woman, or a succubus perhaps, sent by the devil to tempt me. Well, I had a devil of a shock when I slid my hand down that oil-smooth belly and found six inches of stiff cock. I nearly yelled the place down.'

Robert laughed.

But Orm said grimly, 'So the vizier, having determined that your inclination was not towards boys, sent you a woman.'

'She was a copyist at the library. She was called Muzna. But she said that was a corruption of Maria. Once her family had been Christians, become muwallad long ago. The combination of that dark beauty, and the chink of Christian light that might still lodge in her soul, compelled me. When she stayed when the others had gone, when she laughed at my foolish jokes and brought me gifts-'

'When she came to your bed,' Orm said. 'You never could get to the point, could you, priest?'

'She was an addiction, a drug. The smoothness of her skin, the scent of her hair – I had known nothing like it. I would have given my immortal soul for her; indeed, perhaps I have done just that. I was happy, Orm. I was as happy as I have ever been – happy with her, happy to be alive and breathing, and my head not addled as usual with dreams of power and gain. You of all people know me well enough to understand that. But then three calamities happened, in quick succession.'

'Go on.'

'First I was called into the vizier's presence. He had Muzna at his side. She was crying. She stood with him.'

Robert saw it. 'She was his daughter – the vizier's.'

'Yes. He had manipulated her; he had had her seduce me; he used his own daughter to unlock my weakness. I protested that love between a Christian and a Muslim was not unknown. Indeed there was some such love in Muzna's mother's ancestry. But times are changing. As the Christian armies roll down the peninsula like a great smothering carpet, in some taifas the seduction of a Muslim woman by a Christian can be punishable by death – an execution by stoning.' He shuddered. 'And besides, as the vizier pointed out, I am a priest. He could ruin my ecclesiastical career with a word. I could even be excommunicated.'

'But this was all kept just between the three of you,' Orm said.

'Yes. For, of course, the vizier's purpose was not to destroy me but to own me. That was why he used his own daughter. And it worked.

'After that he insisted I showed him all my work. He even asked for a tithe, a share of the income I made from my Arabic Bibles!' He grinned. 'I survived. It just made it harder to conceal my other projects from him. But of course I was never allowed to be alone with Muzna again. Our love had served its purpose, for him.'

'So,' Orm said, 'the first of your three calamities was to learn that Muzna was the vizier's daughter. And the second?'

'To learn she was pregnant.'

It was an accident. The Moorish doctors were as expert in contraception as in so many other fields of medicine, but no method was foolproof.

Sihtric's eyes were bright now. 'Of course she could have got rid of it. Her father's doctors could have helped her with that too. But she wouldn't allow it. She hid away, until the baby was born.'

Robert said, 'Why would she do that?'

'I can only guess. We were never allowed to talk. I believe she wanted the baby as something of her own. She was a good woman, and intelligent. She was sickened at being used by her father. It wasn't much of a plan, but at the very least the baby would make her less useful as a pawn in a marital alliance of lineages – or, worse, a whore.'

Robert said, 'She may have loved you. She may have wanted to keep the baby because it was yours.'

Sihtric bowed his head. 'I can never allow myself to believe that.'

Orm said grimly, 'And your third calamity?'

'She died in childbirth. The baby survived. Not my Muzna.' He said bitterly, 'Again we were let down by the glories of Moorish medicine. The doctors can save a fool of a boy who throws himself at a waterwheel, but not my Muzna!'

Robert said, 'And the child?'

'Was Moraima. My daughter. And the granddaughter of the vizier.'

Robert sat back, shocked.

'So that's why the vizier cares so much about her,' said Orm. 'And why he reacted so strongly when a young Christian buck like Robert came sniffing around.'

Sihtric said, 'And I, I who had found love and comfort, had it snatched away from me. Oh, God is cruel if He is defied!'

Robert, on impulse, touched his shoulder. 'To despair of God is a sin.'

Sihtric looked up, his face full of anguish. 'Yes. But the trouble is, I think He has despaired of me. Well. Now you know it all.'

'Not quite all.' The vizier walked into the room, making the guard step aside.

Robert saw that Moraima waited outside, a flower in the sunlight. Her face was blotchy, as if she had been crying. But she saw him, and smiled weakly.

The vizier walked steadily, apparently sober, but he was pale, drained. 'You haven't told the whole truth, Sihtric,' he said in Latin. 'I know enough English by now to understand that. Isn't a lie by omission still a lie?'

Orm said, 'What whole truth?'

The vizier faced Sihtric. 'The truth of how he took his revenge.'

They were brought out of their battered cell, and returned to an audience room with the vizier. Ibn Tufayl sat on a couch, and sipped a steaming potion. Orm and his party were offered no refreshment.

Moraima stood beside her father, her slim beauty somehow highlighted by the cool abstraction of the patterns on the tiled wall behind her. Robert couldn't take his eyes off her.

'So,' Orm said. 'Let us speak of revenge.'

The vizier glanced around the room, at attendants and soldiers, a doctor who fussed at his elbow. He dismissed them all with a gesture. The soldiers left reluctantly, and Robert saw they took station just outside the room. Ibn Tufayl said, 'Tell them, Sihtric. It's the story of your cunning, after all. And it worked so well!'

So Sihtric, reluctantly, began. He said that after Muzna's death, the two men were locked together in grief and in blood, through Moraima, daughter of one, granddaughter of the other.

'He sent Moraima off to an aunt in Seville,' Sihtric said. 'He promised me he intended nothing but the best for her, but that wasn't good enough for me. I wanted Moraima in my life – she was my daughter, a child for a man who had never expected such a blessing. She was all I had left of Muzna. And besides I didn't trust him. Moraima inherited her mother's beauty – you can testify to that, Robert! I didn't like the idea that in twelve or fifteen or twenty years Ibn Tufayl might use her as he once used her mother.'

The vizier said languidly, 'Don't pretend it was for Moraima or Muzna. It was all for you. Is revenge-taking a sin in your church? It should be.'

'Tell us what you did,' said Orm.

With Muzna dead and Moraima gone, the two men continued to work on their shared project, Aethelmaer's designs.

'I used the opportunity of my time alone with the vizier,' Sihtric said. 'I interested him in the work. I tried to become his friend. And I began to bring him gifts.'

'What gifts?'

'Wine,' said the vizier bluntly.

Wine, forbidden under Muslim custom and law but manufactured in the Christian monasteries still permitted within al-Andalus, and smuggled into Madinat az-Zahra by Sihtric.