After a few minutes Prior Mortimus appeared, bearing an enormous bunch of keys on a ring. There were over thirty, some huge ornamented affairs, centuries old. He handed them to me with a tight smile.

'I beg you not to lose them, sir. They are the only spare set the house possesses.'

I passed them to Mark. 'Carry these, would you? So there is a spare set?'

He avoided replying. 'I have been asked to take you to the infirmary. Brother Guy is expecting you.'

He led us out of the house and back past the workshops, closed and shuttered for it was now dark. The night was moonless and colder than ever. In my tired state the chill seemed to penetrate my bones. We passed the church, from which chanting could be heard. It was a beautiful, elaborate polyphony, accompanied by organ music; quite unlike the off-key warbling I knew from Lichfield.

'Who is your precentor?' I asked.

'Brother Gabriel, our sacrist, is master of music as well. He is a man of many talents.' I caught a sardonic note in the prior's voice.

'Is it not a little late for Vespers?'

'Only a little. Yesterday was All Souls, the monks were standing in church all day.'

I shook my head. 'Everywhere the monasteries follow their own timetable, an easier one than that St Benedict set.'

He nodded seriously. 'And Lord Cromwell is right to say the monks should be kept up to the mark. So far as is in my power, I see that they are.'

We followed the cloister wall separating off the monks' quarters and entered the big herb garden I had seen earlier. Close to, the infirmary was bigger than I had thought. The prior turned the iron ring in the stout door, and we followed him in.

The long infirmary hall stretched before us, its rows of beds on each side widely spaced and mostly empty. It reminded me how shrunken in numbers the Benedictines had become; only at the height of their numbers before the Great Pestilence would the community have needed so large an infirmary. Only three beds were occupied, all by old men in nightshifts. In the first a fat, red-cheeked monk sat up eating dried fruits; he peered at us curiously. The man in the next bed did not look towards us and I saw he was blind, his eyes milky white with cataracts. In the third bed a very old man, his thin face a mass of wrinkles, lay muttering, half-conscious. A figure in a white coif and blue servant's robe stood leaning over him, gently wiping his brow with a cloth. I saw to my surprise that it was a woman.

At a table at the far end, by the little altar, half a dozen monks sat playing cards, their arms bandaged after being bled. They looked up at us with wary eyes. The woman turned and I saw that she was young, in her early twenties. She was tall, with a fine, full figure and a strong square face with high cheekbones. She was not beautiful, but striking. She came across, studying us with intelligent dark-blue eyes before dropping her gaze submissively at the last moment.

'The king's new commissioner, for Brother Guy,' the prior said peremptorily. 'They're to lodge here, they'll need a room prepared.' For an instant, a look of dislike passed between him and the girl. Then she nodded and curtsied. 'Yes, Brother.'

She walked away, disappearing through a door by the altar. She had a poised and confident bearing, quite unlike a young maidservant's normal scuttle.

'A woman within the precincts,' I said. 'That is against the injunctions.'

'We have a dispensation, like many houses, to employ women assistants in the infirmary. The gentle hand of a woman skilled in medicine – though I don't think ye'd get much gentleness from the hands of that malapert. She has manners above her station, the infirmarian's too soft with her.'

'Brother Guy?'

'Brother Guy of Malton – of Malton but not from Malton, as ye'll see.'

The girl returned. 'I will take you to the dispensary, sirs.' She spoke with the local accent; her voice was soft and husky.

'I'll leave ye, then.' The prior bowed and left.

The girl was appraising Mark's costume; he had decked himself out in his finest for the journey and under his fur-trimmed coat he wore a blue jacket over a yellow tunic from which, at the bottom, his codpiece poked out. Her eyes moved to his face; many women looked at Mark, but this one's expression was different: I caught an unexpected sadness in her eyes. Mark gave her a winning smile, and she reddened.

I waved my hand. 'Please lead the way.'

We followed her into a dark, narrow passage with doors leading off. One stood open and glancing in I saw another old monk, sitting up in bed.

'Alice, is that you?' he asked querulously as we passed.

'Yes, Brother Paul,' she said gently. 'I will be with you in a moment.'

'The shaking came again.'

'I will bring you some warm wine.'

He smiled, reassured, and the girl led us on, halting before another door. 'This is Brother Guy's dispensary, sirs.'

My hose brushed against a stone pitcher outside the door. To my surprise it felt warm, and I bent for a closer look. The pitchers were filled with a thick, dark liquid. I sniffed, then jumped up quickly and gave the girl a shocked stare.

'What is that?'

'Blood, sir. Only blood. The infirmarian is giving the monks their winter bleeding. We keep the blood, it helps the herbs grow.'

'I never heard of such a thing. I thought monks were forbidden from shedding blood in any way, even infirmarians. Does not a barber-surgeon come to bleed people?'

'Brother Guy is exempt as a qualified physician, sir. He says keeping the blood is a common enough practice where he comes from. He asks would you wait a few minutes, he has just begun to bleed Brother Timothy and must supervise the process.'

'Very well. Thank you. Your name is Alice?'

'Alice Fewterer, sir.'

'Then tell your master we will wait, Alice. We would not have his patient bleed to death.'

She bowed and went off, wooden heels clacking on the stone flags.

'A well-made girl,' Mark observed.

'So she is. A strange job for a woman, this. I think your codpiece amused her, as well it might.'

'I don't like bleeding,' he said, changing the subject. 'The only time I had it done it left me weak as a kitten for days. But they say it balances the humours.'

'Well, God made me of a melancholy humour and I don't believe bleeding will change that. Now, let's see what we have here.' I unclipped the great bunch of keys from my belt, peering at them in the dim light of a wall lantern until I came to one marked 'Inf.' I tried it and the door swung open.

'Shouldn't we wait, sir?' Mark asked.

'We have no time for niceties.' I took the lantern from the wall. 'It's a chance to learn something about the man who found the body.'

The room was small, whitewashed and very neat, full of a rich spicy odour. A lying couch for the patients was covered with a clean white cloth. Bundles of herbs hung from hooks alongside surgeons' knives. There was a complex astrological chart on one wall, while opposite was a large cross in the Spanish style, dark wood with blood dripping from the five wounds of an alabaster-white Christ. Under a high window, on the infirmarian's desk, papers were neatly ordered in little piles and weighted down with pretty stones. I glanced at notes of prescriptions and diagnoses written in English and Latin.

I made my way along the shelves looking at the jars and bottles, all carefully labelled in Latin script. I lifted the lid from a large bowl to find his leeches, the black slimy creatures wriggling in the unexpected light. It was all as one would expect to find: dried marigolds for fever, vinegar for deep cuts, powdered mice for earache.

At the end of the top shelf were three books. One was a printed volume of Galen, another Paracelsus, both in French. The third, with a beautifully decorated leather cover, was handwritten in a strange language of spiky curls.