how he touches the sheep?’
‘And that is the story of a Christian risking his life for the gospels,’ Brother Peter said piously, pointing to the opposite wall where a man was depicted running past the flames of an open fire, with a cross over his shoulder and an open book in his hand. ‘See the gospels in the library?’
‘I see,’ Ishraq said demurely. In this exquisite and holy place she did not want to tease Brother Peter about his devotion, or to express her own scepticism. She had been raised in the Christian household of Isolde’s father, the Lord of Lucretili, but her mother had taught her to read the Koran. Her later education encouraged her to examine everything, and she would always be a young woman of questions rather than of faith. She looked around the glittering interior and then found her attention caught by a wash of colour on some white mosaic tiles. Someone had glazed the open windows of the mausoleum and one of the pieces of glass had been broken. The morning sunlight, shining over the chipped surface, threw coloured rays on the white tiles and even on Ishraq’s white headscarf.
‘Look,’ Ishraq nudged Isolde. ‘Even the sunlight is coloured in here.’
Her words caught Luca’s attention and he turned and saw the brilliant spread of colours. He was dazzled by the rainbow shining around Ishraq’s head. ‘Give me your scarf,’ he said suddenly.
Without a word, her eyes on his face, she unwrapped it, and her dark thick hair tumbled down around her shoulders. Luca handed one end to her and kept the other. They spread it out to catch the light from the window. At once the white silk glowed with the colours of the rainbow. Together, as if doing a strange dance, they walked towards the window and saw the colours become more diffuse and blurred as the stripes grew wider, and then they walked away again and saw that the brightly coloured beam narrowed and became more distinct.
‘The broken glass seems to be turning the sunlight into many colours,’ Luca said, wonderingly. He turned back to the mosaic that he had been examining. ‘And look,’ he said to her. ‘The mosaic is a rainbow too.’
Above his head was a soaring wall going up to the vault above them, decorated exquisitely in all the colours of the rainbow, and overlaid with a pattern. Luca, his hands holding out Ishraq’s scarf, nodded from the rainbow mosaic to the rainbow on the scarf. ‘It’s the same colours,’ he said. ‘A thousand years ago, they made a rainbow in these very colours, appearing in this order.’
‘What are you doing?’ Isolde asked, looking at the two of them. ‘What are you looking at?’
‘It makes you think that a rainbow must always form the same colours,’ Ishraq answered her when Luca was silent, looking from the scarf to the mosaic wall. ‘Does it? Is it always the colours as they have shown here? In this mosaic? Don’t look at the pattern, look at the colours!’
‘Yes!’ Luca exclaimed. ‘How strange that they should have noticed this, so many hundreds of years ago! How wonderful that they should have recorded the colours.’ He paused in thought. ‘So, is every rainbow the same? Has it been the same for hundreds of years? And if the chip of glass can make a rainbow in here, what makes a rainbow in the sky? What makes the sky suddenly shine with colours?’
Nobody answered him, nobody had an answer. Nobody but Luca would ask such a question; he had been expelled from his monastery for asking questions which verged on heresy, and even now, though he was employed by the Order of Darkness to inquire into all questions of this world and the next, he had to stay within the tight confines of the Church.
‘Why would it matter?’ Isolde asked, looking at the rapt expressions of her two friends. ‘Why would such a thing matter to you?’
Luca shrugged his shoulders as if he was returning to the real world. ‘Oh, just curiosity, I suppose,’ he said. ‘Just as we didn’t know the