I flailed my arms wildly to keep my balance; I had a horror of tipping over and landing face down in the mud. My left leg was still on firm ground and I pulled back with all my strength, terrified that leg too would crunch through a skin of solid ground into some nameless depth. But the ground there held and, sweating with exertion and fear, I was able, painfully slowly, to pull out the other leg, black with mud. A sucking, gurgling sound and a cesspit odour came from the mire. I stepped back and sat with a thump on the path, my heart pounding. My staff lay where it had fallen on the marsh, but I did not think of trying to rescue it. Looking down at my leg encased in stinking mud, I cursed myself for a fool. Lord Cromwell's face would have been worth seeing had he learned that his carefully chosen commissioner had braved the mysteries and dangers of Scarnsea only to fall in a bog and drown.

'You are a noddle,' I said aloud.

I heard a sound behind me, and turned sharply. The gate in the wall was open and Brother Edwig was standing there, a warm coat over his habit, staring at me in amazement.

'Master Sh-Shardlake, are you all right?' He gazed around the bare landscape, and I realized he had heard me talking to myself.

'Yes, Brother Edwig.' I climbed to my feet, realizing I did not cut an impressive figure, bespattered with mud as I was. 'I have had a slight accident. I nearly fell in.'

He shook his head. 'You should not go in there, sir. It is very dangerous.'

'So I see. But what are you doing out here, Brother? Is there no work in the counting house?'

'I have been v-v-visiting the sick novice with the abbot. I wanted to c-clear my head. Sometimes I come out here for a walk.'

I looked at him curiously. He was not someone I could easily imagine tramping through snowy orchards for exercise.

'I like to come out here and l-look out towards the r-r-river. It is c-calming.'

'So long as one minds one's footing?'

'Er – yes. C-can I help you back, sir? You are c-covered with mud.'

I was starting to shiver. 'I can manage. But yes, I should go back.'

We returned through the gate and plodded back to the monastery. I went as fast as I could, my sodden leg like a block of ice.

'How is the novice?'

He shook his head. 'He appears to be r-recovering, but one can never tell with these chesty agues. I had one m-myself last winter; it kept me out of the c-counting house two weeks.' He shook his head.

'And what is your opinion of Simon Whelplay's treatment by the prior?'

He shook his head again, impatiently. 'It is d-difficult. We must have discipline.'

'But should one not temper the wind to the shorn lamb?'

'P-people need certainty, they n-need to know that if they do wrong they will be p-punished.' He looked at me. 'Do you not th-think so, sir?'

'Some people find it harder to learn than others. I was told not to go in that bog, but I did.'

'But that was a mistake, sir, not a sin. And if one finds it hard to learn, all the more reason to give a firm lesson, surely. And that boy is weakly, he could have taken an ague in any case.' His tone was stern.

I raised my eyebrows. 'You appear to view the world in black and white, Brother.'

He looked puzzled. 'Of course, sir. Black and white. Sin and virtue. God and the Devil. The rules are laid down and we must follow them.'

'Now the rules are laid down by the king, not the pope.'

He looked at me seriously. 'Yes, sir, and we must follow those.'

I reflected that that was not what Brother Athelstan had reported him and the others as saying. 'I understand, Brother Bursar, that you were away on the night Commissioner Singleton was killed?'

'Y-yes. We have some estates over at W-Winchelsea. I was not happy with the steward's accounts, I rode over to make a spot check. I was away three nights.'

'What did you uncover?'

'I thought he'd b-been cheating us. But it was just a matter of errors. I've sacked him, though. If people can't keep proper ac-c-counts they're no good to me.'

'Did you go alone?'

'I took one of my assistants, old Brother William, whom you saw in the counting house.' He looked at me shrewdly. 'And I was at the steward's house the night Commissioner S-Singleton was killed. G-God rest him,' he added piously.

'You have many duties then,' I said. 'But at least you have assistants to help you. The old man and the boy.'

He gave me a sharp look. 'Yes, though the boy's more trouble than he's worth.'

'Is he?'

'No head for figures, n-none at all. I have s-set him to looking out the books you requested, they should b-be with you soon.' He almost slipped, and I caught his arm.

'Thank you, sir. By Our Lady, this snow!'

For the rest of the journey he concentrated on where he was putting his feet, and we said little more till we reached the monastery precinct. We parted in the courtyard; Brother Edwig returned to his counting house and I turned my steps back towards the infirmary. I needed some dinner. I thought about the bursar; a jack-in-office, obsessed with his financial responsibilities probably to the exclusion of all else. But devoted to the monastery too. Would he be prepared to countenance dishonesty to protect it, or would that mean crossing the line between white and black? He was an unsympathetic man, but as I had said to Mark the night before, that did not make him a murderer any more than the sympathy I felt for Brother Gabriel made him innocent. I sighed. It was hard to be objective among these people.

As I opened the infirmary door, all seemed quiet. The hall was deserted. The sick old man lay quietly in his bed, the blind monk was asleep in his chair and the fat monk's bed was empty; perhaps Brother Guy had persuaded him it was time to leave. A fire crackled welcomingly in the grate and I went to warm myself for a moment.

As I stood watching steam rise from my wet hose, I heard sounds from within; confused, fractured noises, cries and shouts and the crash of pottery breaking. The sounds came closer. I stared in astonishment as the door to the sick rooms burst open and a tangle of struggling figures fell into the hall: Alice, Mark, Brother Guy, and at the centre a thin figure in a white nightshirt, who as I watched threw the others off and staggered away. I recognized Simon Whelplay, but he was a very different figure now from the half-dead wraith I had seen the night before. His face was puce, his eyes wide and staring and there was a froth of spittle at the corner of his mouth. He seemed to be trying to speak but could only gasp and retch.

'God's blood, what's happening?' I called out to Mark.

'He's gone stark mad, sir!'

'Spread out! Catch him!' Brother Guy shouted. His face was grim as he nodded to Alice, who moved to one side, spreading her arms. Mark and Brother Guy followed her example and they closed in on the novice, who had come to a halt and stood staring wildly around. The blind monk had woken and sat twisting his head anxiously around, his mouth agape. 'What is it?' he asked tremulously. 'Brother Guy?'

Then a dreadful thing happened. It seemed to me that Whelplay caught sight of me and at once bent his trunk forward in imitation of my twisted gait. Not only that, but he stretched forth his arms and began waving them to and fro, seeming to waggle his fingers mockingly. It is a mannerism I have when I am excited, so those who have seen me in court have told me. But how could Whelplay know such a thing? I was taken back again to those schooldays I had been reflecting on, when cruel children would imitate my movements, and I confess that as I watched the novice staggering about, bent and gesticulating, the hair rose on my neck.

I was brought to my senses by a shout from Mark. 'Help us! Catch him, sir, for pity's sake, or he'll get out!' My heart thumping, I too spread my arms and approached the novice. I looked into his eyes as I came closer and they were terrible to see, the pupils twice the normal size, staring wildly, without recognition even as he performed his mocking stagger. Brother Gabriel's talk of satanic forces came back to me and I thought with a jolt of sudden terror that the boy was possessed.