'Look at this, Mark.'

He peered over my shoulder at the book. 'Some medical code?'

'I don't know.'

I had had an ear open for footsteps, but had heard nothing and jumped at the sound of a polite cough behind us.

'Please do not drop that book, sir,' a strangely accented voice said. 'It is of great value to me if no-one else. It is an Arabic medical book, it is not on the king's forbidden list.'

We spun round. A tall monk of about fifty, with a thin, austere face, was looking at us calmly from deep-set eyes. To my surprise, his face was brown as an oak plank. I had seen brown men occasionally in London, by the docks, but had never found such a being staring me in the eye.

'I would be most thankful if you could give me the book,' he said in his soft, lisping voice, respectfully but firmly. 'It was given to my father by the last emir of Granada.'

I handed it to him and he bowed gracefully.

'You are Master Shardlake and Master Poer?'

'Indeed. Brother Guy of Malton?'

'I am. You have a key to my room? Normally only my assistant Alice comes in here unless I am present, lest someone mess with the herbs and potions. The wrong dose of some of these powders could kill, you see.' His eyes flickered over the shelves. I found myself reddening.

'I have been careful to touch nothing, sir.'

He bowed. 'Quite so. And how may I assist His Majesty's representative?'

'We wish to take accommodation here. You have guest rooms?'

'Certainly. Alice is preparing a room now. But most of this corridor is taken up with aged monks. They often require attention in the night and you may find yourself disturbed. Most guests prefer the abbot's house.'

'We would rather stay here.'

'As you wish. And may I help in any other way?' His tone was perfectly respectful, but somehow his questions made me feel like a foolish patient asked to check off symptoms. However strange his appearance, this was a man of presence.

'I gather you have charge of the body of the late commissioner?'

'I have. It is in a crypt in the lay cemetery.'

'We would like to view it.'

'Most certainly. In the meantime perhaps you may wish to wash and rest after your long journey. Will you be dining with the abbot later?'

'No, we will eat with the monks in the refectory, I think. But first I think we will take an hour's rest. That book,' I added, 'you are a Moor by birth?'

'I am from Malaga, now in Castile but when I was born part of the emirate of Granada. When Granada fell to Spain in 1492 my parents converted to Christianity, but life was not easy. In due course we made our way to France; we found life easier at Louvain, it is an international town. Arabic was, of course, their language.' He smiled gently, but his coal-black eyes stayed sharp.

'You studied medicine at Louvain?' I was astonished, for it was the most prestigious school in Europe. 'Surely you should be serving at the court of a noble or a king, not in a remote monastery.'

'Indeed so; but as a Spanish Moor I have certain disadvantages. Over the years I have bounced from post to post in France and England, like one of your King Henry's tennis balls.' He smiled again. 'I was at Malton in Yorkshire five years; I kept the name when I came here two years ago. And if rumour speaks true, I may be on the move again soon.'

I remembered he was one of the officials who knew of Singleton's purpose. He nodded reflectively at my silence.

'So. I will take you to your room, and I will return in an hour so you can inspect Commissioner Singleton's body. The poor man should be given Christian burial.' He crossed himself, sighing. 'It will be hard enough for the soul of a murdered man to find rest, unconfessed and without the last sacrament at his end. Pray God none of us should ever meet such a fate.'

Our room in the infirmary was small but comfortable, wood-panelled and with new, sweet-scented rushes on the floor. It was warmed by a fire, before which chairs had been set. The girl Alice was there when Brother Guy showed us in, laying towels beside a pitcher of warm water. Her face and bare arms had a healthy flush from the fire.

'I thought you might like to wash, sirs,' she said deferentially.

I smiled at her. 'That is most kind.'

'I need something to get me warm,' Mark said, giving her a grin. She lowered her head and Brother Guy gave Mark a stern look.

'Thank you, Alice,' he said. 'That will be enough.' The girl bowed and left.

'I hope the room is comfortable. I have sent word to the abbot you will be dining in the refectory.'

'This room will do very well. Thank you for your trouble.'

'If you have any needs, Alice will attend to them.' He gave Mark another sharp look. 'But please bear in mind that she has many duties with the aged and sick monks. And that she is a woman alone here, apart from some old kitchen maids. She is under my protection, such as it is.'

Mark coloured. I bowed to the infirmarian. 'We will remember that, sir.'

'Thank you, Master Shardlake. Then I will leave you.'

'Black old moldwarp,' Mark grumbled when the door closed. 'It was only a look – and she was pleased to get it.'

'He is responsible for her welfare,' I said shortly.

Mark looked at the bed. It was one of those with a high bed for the master and a narrow space underneath where a servant's wooden bunk slid in and out on wheels. He pulled out the lower tier and looked gloomily at the hard board covered with a thin straw mattress, before removing his coat and sitting down.

I went over to the ewer and splashed some warm water on my face, letting it drip down my neck. I felt exhausted; my head was spinning with the kaleidoscope of faces and impressions of the last few hours. I groaned. 'Thank God we're alone at last.' I sat down in the chair. 'Christ's wounds, I'm sore.'

Mark looked up at me with concern. 'Does your back pain you?'

I sighed. 'It will be better after a night's rest.'

'Are you sure, sir?' He hesitated. 'There are cloths there, we could make a hot poultice… I could apply it for you.'

'No!' I snapped. 'Will you be told, I'll be all right!' I hated anyone looking at my deformed back; only my physician was allowed to do that and then only when it was especially painful. My skin crawled at the thought of Mark's eyes on it, his pity and perhaps disgust, for why should someone formed as he was not feel disgust? I pulled myself to my feet and went over to the window, looking out over the dark, empty quadrangle. After a few moments I turned round; Mark was looking up at me, resentfulness mixed with anxiety in his face. I raised a hand apologetically.

'I am sorry, I should not have shouted.'

'I meant no ill.'

'I know. I am tired and worried, that is all.'

'Worried?'

'Lord Cromwell wants a result quickly and I wonder if I will be able to get one. I had hoped for – I don't know, some fanatic among the monks who had already been locked up, at least some clear pointer to the culprit. Goodhaps is no help; he's so scared he'd leap at his own shadow. And these monkish officials do not seem likely to be easily overawed. On top of that we seem to have a mad Carthusian stirring up trouble, and talk of a break-in by practitioners of dark arts from the town. Jesu, it's a tangle. And that abbot knew his law, I can see why Singleton found him difficult.'

'You can only do what it is in your power to do, sir.'

'Lord Cromwell would not see things that way.' I lay down on the bed, staring at the ceiling. Usually when I began grappling with a new case I would enjoy a sense of pleasurable excitement, but here I could see no thread to guide me through what seemed an enormous labyrinth.

'This is a gloomy place,' Mark said. 'All those dark stone corridors, all those arches. Each one could hide an assassin.'