'I worked for an hour, then said my prayers and went to bed.'

'And slept?'

'Yes. I woke suddenly at about five. There was a commotion outside, then a great bang on the door – just like the prior made just now.' He shuddered. 'The abbot and a dozen monks were outside. The abbot looked shocked, startled out of his wits. He told me the commissioner was dead, someone had killed him, I must come at once.

'I dressed and went down with them. It was all so confused, everyone was babbling about locked doors and blood, and I heard someone say it was God's vengeance. They found torches and we went through the monks' quarters to the kitchens. It was so cold, all those endless dark passageways, monks and servants standing around in little huddles looking scared. And then they opened the door to the kitchen. Dear God.' To my surprise, he quickly crossed himself.

'There was this smell of-' he gave a fractured laugh – 'a butcher's shop. The room was full of candles, they'd put them on the long tables, the food cupboards, everywhere. I stood in something, and the prior pulled me to one side. When I lifted my foot it was sticky. There was a great pool of dark liquid on the floor, I didn't know what it was.

'Then I saw Robin Singleton lying in the middle of it on his stomach, his robe all smeared. I knew there was something wrong, but my eyes could make no sense of it at first. Then I realized he had no head. I stared round and then I saw it, his head, lying under the butter churn glaring up at me. It was only then I realized the pool was blood.' He closed his eyes. 'Dear God, I was so frightened.' He opened them again, emptied his cup and reached once more for the bottle, but I covered it with my hand.

'Enough for now, Dr Goodhaps,' I said gently. 'Go on.'

Tears came into his eyes. 'I thought they'd killed him, I thought it was an execution and I was next. I looked at their faces, looked to see which one was carrying an axe. They all looked so grim. That Carthusian was there, smiling horribly, and he called out "Vengeance is mine, saieth the Lord."'

'He said that, did he?'

'Yes. The abbot snapped, "Be quiet," at him, and came over to me. "Master Goodhaps," he said, '"you must tell us what to do," and then I realized they were all as frightened as I.'

'Might I say something?' Mark ventured. I nodded.

'That Carthusian couldn't have struck someone's head off. It would take strength and balance.'

'Yes, it would,' I nodded. 'You're quite right.' I returned to the old man. 'What did you say to the abbot?'

'He said we should consult the civil authorities, but I knew Master Cromwell should be told first. I knew there would be political implications. The abbot said that the gatekeeper, old Bugge, had reported meeting Singleton on his night rounds not an hour before. He told Bugge he was on his way to meet one of the monks.'

'At that time? Did he say whom?'

'No. Singleton sent him away with a flea in his ear apparently.'

'I see. What then?'

'I ordered all the monks to strict silence. I said no letters should leave this place without my approval, and sent my letter out via the village postboy.'

'You did well, Master Goodhaps, your thinking was quite right.'

'Thank you.' He wiped his eyes with his sleeve. 'I was sore afraid, sir. I came back here and here I have stayed. I am sorry, Master Shardlake, this has unmanned me. I should have made enquiries, but – I am only a scholar.'

'Well, we are here now. Tell me, who found the body?'

'The infirmarian, Brother Guy. That dark monk.' He shuddered. 'He said there was an old brother sick in the infirmary and he came to get some milk from the kitchen. He has a key. He unlocked the outer door then went up the little hall to the kitchen. When he opened the door and stepped into the pool of blood he raised the alarm.'

'So the kitchen is normally locked at night?'

He nodded. 'Yes, to stop the monks and servants helping themselves. The monks think of nothing but stuffing their bellies, you'll see how fat most of them are.'

'So the murderer had a key. Like the meeting the gatekeeper reported, that points to someone from inside the monastery. But you said in your letter that the church was desecrated, a relic stolen?'

'Yes. We were all still standing in the kitchen when one of the monks brought news that-' he swallowed, 'that a cock had been sacrificed on the church altar. Later they found the relic of the Penitent Thief stolen too. The monks are saying some outsider came in to desecrate the church and steal the relic, encountered the commissioner on one of his late wanderings, and killed him.'

'But how would an outsider have entered the kitchen?'

He shrugged. 'Bribed a servant to make a copy of the key perhaps? That's what the abbot thinks, though the cook is the only servant with a key.'

'What about the relic? Was it valuable?'

'That horrible thing! A hand nailed to a piece of wood. It was in a big gold casket set with stones: they were real emeralds, I believe. It is believed to cure broken or twisted bones, but it's just another fake to gull the foolish.' For a moment his voice rose with a reformer's ardour. 'The monks are more upset about the relic than about Singleton's murder.'

'What do you think?' I asked. 'Who do you think could have done this?'

'I don't know what to think. The monks talk of Devil-worshippers breaking in to steal the relic. But they hate us, you can feel it in the very air. Sir, now you are here, may I go home?'

'Not just yet. Soon, perhaps.'

'At least I will have you and the boy here.'

There was a knock at the door, and the servant poked his head in.

'The abbot has returned, sir.'

'Very well. Mark, help me up. I am stiff.' He aided me to my feet and I brushed myself down.

'Thank you, Dr Goodhaps, we may talk again later. By the way, what happened to the account books the commissioner was studying?'

'The bursar took them back.' The old man shook his white poll. 'How did it come to this? All I wanted to see was reform of the Church; how has it come to a world where these things happen? Rebellion, treason, murder. Sometimes I wonder if there is a way through it all.'

'There is a way at least through the mysteries men make,' I said firmly. 'That I believe. Come on, Mark. Let us go and meet the good lord abbot.'

The servant led us down the staircase again and showed us into a wide room whose walls were hung with colourful Flemish tapestries, old but very fine. The windows looked over a large cemetery dotted with trees, where a couple of servants were raking away the last of the leaves.

'My lord abbot is changing out of his riding clothes. He will be with you shortly.' He bowed himself out, and we stood warming our rears at the fire.

The room was dominated by a large desk covered with a clutter of papers and parchments, a cushioned chair behind it and stools in front. The great seal of the abbey lay on a block of sealing wax in a brass tray, next to a flagon of wine and some silver cups. Behind the desk, bookshelves lined the wall.

'I didn't realize abbots lived so well,' Mark observed.

'Oh yes, they have their own separate households. Originally the abbot lived among the brethren, but when the Crown started to tax their households centuries ago they hit on the device of giving the abbot his own revenues, legally separate. Now they all live in fine state, leaving most of the daily supervision to the priors.'

'Why doesn't the king change the law, so the abbots can be taxed?'

I shrugged. 'In the past kings needed the abbots' support in the House of Lords. Now – well, it won't matter for much longer.'

'So that Scottish brute actually runs the place from day to day?'