'I was a Muslim savouring communion wine – the blood of your Christ! Ironic, isn't it? But it was more than a taste that Sihtric cultivated in me. You are a good judge of men, priest. If I saw a weakness in you, you saw one in me, one I didn't know I possessed.'

'You became a drunk,' Orm said.

'The priest was the only route through which I could obtain the wine I needed. Thus I gave him power over me.'

'But,' Robert said, 'what did you want, Sihtric?'

'Moraima,' Sihtric said.

The two men struck a deal. Moraima would be brought back to Cordoba and raised as Sihtric's daughter. She would be a good Muslim, though: the vizier would not tolerate his granddaughter being raised a Christian.

'The girl would be known as my daughter,' Sihtric said. 'But her descent from the vizier was to be kept a secret. Ibn Tufayl let my reputation suffer rather than his. The Christian community was scandalised.'

'So,' Orm said. 'You, Sihtric, armed with your control of the vizier through his drunkenness. And the vizier knowing that you fathered a child by a Muslim girl. The two of you locked together in your weakness, mutually dependent, mutually loathing. I should have known I would find you in a situation like this, priest. It's just the sort of mess which always gathers around you.'

'It's almost a work of art, isn't it?' Sihtric said bitterly.

'I don't want to hear any more of this.' Moraima stepped forward, anger bringing colour to her cheeks. 'I don't want to be discussed as if I were just another barrel of wine, a business deal between two weak old men.'

The vizier said, 'Now, Moraima-'

'Oh, let her go,' Sihtric said. 'Why should she hear this painful old rubbish hashed over once again? Go, child; find yourself something more pleasant to do.'

'And me,' Robert said impulsively. 'Let me walk with her.'

Ibn Tufayl studied him. 'You must be even more stupid than you look.'

Robert blurted, thinking as he spoke, 'I can never have Moraima, and she can't have me. How we feel doesn't matter. It's over – indeed, it never was. Just let us walk together for an hour. Let us say goodbye.'

Orm said, 'Vizier, I take it you've no plans to punish the boy over Ghalib.'

'For what? He behaved nobly enough.' Ibn Tufayl's raging temper had vanished with his intoxication. 'Besides, the fault is ours, mine and Sihtric's, for allowing such situations to develop. That is what we must discuss. For as Moraima grows older-'

'Yes,' Sihtric said. 'We need to work out a way to manage her heart.'

'But for now,' Orm said, 'let them go.'

Ibn Tufayl clapped his hands to summon in his guards. 'Very well. Go, you two. Be aware you will be watched, every step of the way.'

Robert, hugely relieved to be getting away from Sihtric and the vizier and all their murky compromises, followed Moraima to the door.

But as he passed his father, Orm whispered, 'Just be careful.'

Outside the light of the low afternoon sun seemed dazzling bright. The guard stood just a pace away, his arms folded, glaring.

Robert faced the girl. 'Moraima, I-'

'Hush. Don't talk. Not here.'

They walked across the palace compound. They soon reached ruins, for only a fraction of Madinat az-Zahra had been restored to habitability by the vizier's workmen. But Moraima knew the way, and led Robert further. Following rubble-strewn paths they came to a complex of high walls and fallen roofs, where tiles and broken stucco littered a weed-cracked floor. 'Once a harem,' Moraima whispered. 'Complicated place. Easy to get lost. Come on.' She took his hand, and they ran, turning left then right and doubled back, hurrying between high walls and across empty, broken floors. Robert soon became lost himself, even though the afternoon sun hung as a constant beacon in the sky.

And before long the vizier's guard had been completely left behind.

She brought him to a ruined patio. Weeds clogged ponds long since stagnant, wiry little bushes pushed through cracks in the paving stones, and palms had outgrown the gardeners' neat configurations and gone wild. The walls of the rooms here were burned out and open to the sky. But some of the arches still stood, still serving as doorways to this secret garden.

For Robert, walking into this place with Moraima at his side was a fulfilment of the overheated, fragmentary fantasies he had had since he first arrived in Cordoba.

They found a stone bench and sat. A small bird fluttered away, disturbed. Somewhere a guitar played, and a thin voice sang a plaintive song.

'I like it here,' Moraima said. 'Even though nobody has touched it for fifty years. I like the idea that a place can be beautiful even when the people have vanished, that things will go on when all our fussing and fighting is over. If this is all we leave behind when we've gone, a pretty place where the birds can nest, perhaps that's enough.'

He took her hand. In fact it felt like a bird in his palm, the bones thin, fragile, the flesh warm. 'That's a melancholy thought.'

She smiled, enigmatic. 'But you've seen how I live. They say they love me, the two of them.'

'Sihtric and Ibn Tufayl.'

'Father and grandfather. I sometimes think that all they do is use me to hurt each other. And sometimes, it's awful, sometimes I think they don't love me at all. That they blame me for killing my mother, who they both loved more than they love me.'

He wanted to comfort her, to reassure her that couldn't be true. But the priest and the vizier were complicated, ugly creatures, locked together, feeding off each other's weakness and pain. How could he say if they loved her well or not? No wonder she dreamed of a world without humans.

'Moraima, I've heard what they want. But what do you want? What kind of life?'

'I don't know,' she said honestly. 'I can't imagine it. Things are too complicated. But…'

'Yes?'

'It doesn't feel complicated when I'm with you.'

His heart hammered. 'If it wasn't for the others – my father, yours, the vizier – if things were different-'

'If Jesus and Muhammad had never existed? What's the good of talking like that? Things are as they are; you can't change the past.'

But her father, he thought, seemed to believe that the past could be changed. 'But even so. If it was only a question of the two of us, could we make a life together?'

She said firmly, 'We can never know. Because it isn't going to happen, is it? All we have is this moment.' Her face was before his, softened by nearness, her eyes huge, the colours of the wild garden reflected in her smooth skin. 'That's all anybody has.'

'Then we should grasp it.'

Their lips closed together. Her breath was like the breeze off the desert. 'I don't even mind,' she whispered into his mouth, 'that you smell so bad.'

They kissed again, and he felt as if he was passing through another arched gateway into a still more wonderful place yet.