‘You really are a hopeless servant for a religious man,’ Peter remarked. ‘Wouldn’t you have done better in an ale house?’

‘And how would the little lord manage without me?’ Freize demanded indignantly. ‘Who watched over him in the monastery and kept him safe? Who fed him when he was nothing more than a long-legged sparrow? Who follows him now wherever he goes? Who keeps the door for him?’

‘Did he watch over you in the monastery?’ Peter asked, turning in surprise to Luca.

Luca laughed. ‘He watched over my dinner and ate everything I left,’ he said. ‘He drank my wine allowance. In that sense he watched me very closely.’

At Freize’s protest, Luca thumped him on the shoulder. ‘Ah, all right! All right!’ To Peter he said: ‘When I first entered the monastery he watched out for me so that I wasn’t beaten by the older boys. When I was charged with heresy he gave witness for me, though he couldn’t make head nor tail of what they said I had done. He has been loyal to me, always, from the moment of our first meeting when I was a scared novice and he was a lazy kitchen boy. And when I was given this mission he asked to be released to go with me.’

‘There you are!’ Freize said triumphantly.

‘But why does he call you “little lord”?’ Peter pursued.

Luca shook his head. ‘Who knows? I don’t.’

‘Because he was no ordinary boy,’ Freize explained eagerly. ‘So clever and, when he was a child, quite beautiful like an angel. And then everyone said he was not of earthly making . . .’

‘Enough of that!’ Luca said shortly. ‘He calls me “little lord” to serve his own vanity. He would pretend he was in service to a prince if he thought he could get away with it.’

‘You’ll see,’ Freize said, nodding solemnly to Brother Peter. ‘He’s not an ordinary young man.’

‘I look forward to witnessing exceptional abilities,’ Brother Peter said drily. ‘Sooner rather than later, if possible. Now, I’m for my bed.’

Luca raised his hand in goodnight to the two of them and turned into the priest house. He closed the door behind him and pulled off his boots, putting his concealed dagger carefully under the pillow. He laid out the paper about the number zero on one side of the table, and the statements that Peter had written down on the other. He planned to study the statements and then reward himself with looking at the manuscript about zero, working through the night. Then he would attend the service of Lauds.

At about two in the morning, a tiny knock at the door made him move swiftly from the table to take up the dagger from under his pillow. ‘Who’s there?’

‘A sister.’

Luca tucked the knife into his belt, at his back, and opened the door a crack. A woman, a veil of thick lace completely obscuring her face, stood silently in his doorway. He glanced quickly up and down the deserted gallery and stepped back to indicate that she could come inside. In the back of his mind he thought he was taking a risk letting her come to him without witnesses, without Brother Peter to take a note of all that was said. But she too was taking a risk, and breaking her vows, to be alone with a man. She must be driven by something very powerful to step into a man’s bedroom, alone.

He saw that she held her hands cupped, as if she were hiding something small in her palms.

‘You wanted to see me,’ she said quietly. Her voice was low and sweet. ‘You wanted to see this.’

She held out her hands to him. Luca flinched in horror as he saw that in the centre of both was a neat shallow hole, and each palm was filled with blood. ‘Jesu save us!’

‘Amen,’ she said instantly.

Luca reached for the linen washcloth and tore a strip roughly off the side. He splashed water onto it from the ewer, and gently patted each wound. She flinched a little as he touched her. ‘I am sorry, I am sorry.’

‘They don’t hurt much, they’re not deep.’

Luca dabbed away the blood and saw that both wounds had stopped bleeding and were beginning to form small scabs. ‘When did this happen?’

‘I woke just now, and they were like this.’

‘Has it happened before?’

‘Last night. I had a terrible dream, and when I woke I was in my cell, in my bed, but my feet were muddy and my hands were filled with blood.’

‘I think that it was you that I saw,’ he said. ‘In the entrance yard? Do you remember nothing?’

She shook her head and the lace veil moved but did not reveal her face. ‘I just woke and my hands were like this, newly marked. It has happened before. Sometimes I have woken in the morning and found them wounded but they have already stopped bleeding, as if they came earlier in the night, without even waking me. They are not deep, you see, they heal within days.’

‘Do you have a vision?’

‘A vision of horror!’ she suddenly broke out. ‘I cannot believe it is the work of God to wake me with bleeding hands. I have no sense of holiness, I feel nothing but terror. This cannot be God stabbing me. These must be blasphemous wounds.’

‘God might be working through you, mysteriously . . .’ Luca tried.

She shook her head. ‘It feels more like punishment. For being here, for following the services, and yet being cursed with a rebellious heart.’

‘How many of you are here unwillingly?’

‘Who knows? Who knows what people think when they go through each day in silence, praying as they are commanded to do, singing as they are ordered? We are not allowed to speak to one another during the day except to repeat our orders or say our prayers. Who knows what anyone is thinking? Who knows what we are all privately thinking?’

She spoke so powerfully to Luca’s own sense that the nunnery was full of secrets that he could not bring himself to ask her anything more, but chose to act instead. He took a sheet of clean paper. ‘Put your palms down on this,’ he commanded. ‘First the right and then the left.’

She looked as if she would like to refuse but did as he ordered, and they both looked, in horror, at the two neat triangular prints that her blood left on the whiteness of the manuscript and the haze of her bloody palm print around them.

‘Brother Peter has to see your hands,’ Luca decided. ‘You will have to make a statement.’

He expected her to protest; but she did not. She bowed her head in obedience to him.

‘Come to my inquiry room tomorrow, first thing,’ he said. ‘Straight after Prime.’

‘Very well,’ she said easily. She opened the door and slipped through.

‘And what is your name, Sister?’ Luca asked, but she was already gone. It was only then that he realised that she would not come to the inquiry room and testify, and that he did not know her name.

Luca waited impatiently after Prime, but the nun did not come. He was too irritated with himself to explain to Freize and Brother Peter why he would see no-one else, but sat in the room, the door open, the papers on the table before them.