A spider emerges from a crevice in the cold limestone wall and waits. Far below, amidst a tiny pool of flickering light, Father Thomas dips a quill into coal-black ink and stares absently at the squat candle. And then,biting his lip, he peers down at the word he has written. A memory puckers his brow and forces a grimace. He wipes a tear from his eye,inhales deeply through his nostrils and resumes the letter. The words splutter and falter, bunching into short desperate sentences. His tight lips twitch involuntarily, punctuating each syllable as if sewn together in macabre penance. When he is done, the priest folds the letter and with shaking hands slides it into an envelope. A rush of wind rattles the shutters and delivers an echo of cawing crows. Father Thomas kisses the envelope and makes the sign of the cross. The candle flame shrinks and snuffs to a glowing ember, unravelling an ethereal black snake that slithers up into the rafters, past the all-seeing spider and its silver web.

The bell for Lauds tolled across the courtyard, and Father Thomas realised he had not slept. He had sat hunched on the edge of his cot, the envelope pressed between his palms like a relic he was afraid to drop. When he did eventually rise he walked the long cloister with his eyes fixed on the flagstones, where the brothers passed him in silence, hoods drawn, and he could not tell whether their lowered gazes were reverence or knowledge. Perhaps it made no difference. In a place like this, a secret was only a rumour that hadn't yet found its mouth.

Brother Anselm was waiting at the gatehouse, a boy of nineteen with ink-stained fingers. He took the envelope with both hands.

"To the Bishop at Aldermoor," Father Thomas said. His voice cracked; he cleared his throat and tried again. "Into his hands only."

"Yes, Father." Anselm turned the envelope over and saw the wax seal, the crest of the order pressed deep into the crimson. His brow creased. "Is it grave, Father?"

"It is finished," said Thomas.

He watched the boy hurry through the gate and down the mud road until the mist swallowed him. Only then did he allow himself to lean against the cold stone and close his eyes.

Sister Anne.

He had tried all night not to think her name. It rose now regardless; he saw her as she had stood before the tribunal three weeks ago, small in her grey habit, hands folded, chin lifted. When they asked her to recant, she had looked at each of the six judges in turn, and then at him, with weepy eyes, and said quietly, "I cannot unsee what I have seen, Father. Would you have me lie to God to comfort men?"

The decree had been precise. He had written it in the language of necessity, each phrase a stone laid upon the last. Obstinate in error. Contumacious before the tribunal. A danger to the souls entrusted to her. And then the sentence: to be immured in perpetuity, walled within the chapel crypt, that she may repent in silence before the face of the Almighty.

That evening the chapter house filled with the dull murmur of men who knew something was coming. Father Thomas stood at the head of the long table, the six judges arranged along its sides like crows on a fence. Prior Benedict, silver-haired and serene, folded his hands over his stomach.

"It is done, then?" asked Benedict.

"The decree has gone to Aldermoor. The Bishop will seal it within the week."

A murmur passed among them.

"You have done a hard thing, Thomas," Benedict said. "A necessary thing. Two novices have already come to me, troubled by her story."

"Her abbey was burned," Thomas said. His mouth had gone dry. "She spoke only of what she claimed to have seen."

"And Abbess Margery says she is troubled beyond the Father's help." Benedict's tone remained gentle, which made it worse. "Mercy lies keeping the well healthy, not in saving the already dead."

Then why does it feel like murder?

He did not say it. He bowed his head instead and murmured the expected assent, and the others took it as confirmation. The brothers filed out, their lanterns shrinking down the corridor, until Thomas stood alone in the dark with the smell of tallow. Sleep would not come. At the hour when even the owls fell quiet, he found himself walking, drawn by something he refused to name, down the narrow spiral stair that led beneath the chapel.

The crypt was cold as a dead thing. He carried no lantern, only a single candle that bent and shivered in the draught, making the shadows of the stone lean int towards him. Along the far wall, a recess had already been marked in chalk, a rectangle just wide enough for a kneeling woman, and beside it, stacked neat as bread, the pale blocks that would close it. Thomas set the candle on the floor and pressed his palm flat against the stone. It was damp. Somewhere in the dark, water dripped with the patience of a clock.

"Forgive me," he whispered. He did not know whether he spoke to God, to the nun, or to the boy he had once been, the one who had taken his vows believing that faith was a lamp and not a blade.

The candle guttered. In the weak light, something caught his eye on the wall above the recess. He leaned closer. It was a mark, a small circle with rays reaching outward, cut by some forgotten hand.

A sun. Or an eye.

Behind him, softly, a footstep scraped on stone. Thomas turned. The stair was empty, a black mouth yawning upward.

"Who is there?"

Then, after a long silence, from very far above, the sound of a woman humming. He knew the tune. He had heard it only once, drifting from a cell window the night before the tribunal. It was a hymn he had never learned, in a language he could almost understand.

As Brother Anselm leaned against a smooth rocky outcrop to catch his breath, he watched the new day dawning, pale and ambiguous on the distant horizon. He was descending now and the worst of the nights journey lay behind, and way above him. Still, the exposed path dropped steeply ahead of him, constantly appearing and disappearing in the damp transient mist. He detected the salt in the air and thought he could already hear the distant crashing of waves. His proximity to the valley bottom was realised when the wind brought to his ears the muted clanging of a goat herd. With a renewed impetus Brother Anselm resumed his descent.

Weary and in need of nourishment, he walked across the small stone bridge which marked the end of the mountain trail, and where it joined with the rutted road that would lead him to the ferry which, if it be Gods will, would deliver him safely to the mainland. He cursed his weakness, he cursed his desire to be back in the company of his Brothers, seated at the table, eating breakfast, oh and the sweet sweet bread baked by dear old Tomas. He had no money. On the road, he was totally reliant on the charity of others; it was their way. But two things troubled him. He knew that there were no dwellings between him and the ferry, some five miles distant. And second, today was the sabbath. His hand tapped his breast, that was all that was needed to remind him of his purpose and to reassure him that the bursa containing the letter was still there, safe and sound beneath his cassock.

There were no other travellers on the road that Brother Anselm saw. He walked on the fringes to avoid the mud and the water filled ruts but he was plagued by stones which found their way into his sandal's causing him to wince with pain. In due course he reached the small wooden shrine which had been placed atop a small ridge overlooking the boat jetty. He knelt before it, as countless other travellers had done before, as he had knelt before, and he prayed for Gods deliverance from foul weather and restless water. As he knelt in silence he heard once again the clanging bells of a goat herd - only this time it was much nearer. As Brother Anselm stood and got his first glimpse of the jetty, he could see the goats being shepherded onto the boat and that the ferryman, a man all too familiar to Brother Anselm, was supervising the activity with all his usual bluster and impatience. Known to all as the Master, he was a tall, strong man with hands the size of yeast loaves. He was also a stranger to bathing and attracted flies. Brother Anselm had previously witnessed the Master's temper and the suffering he was readily disposed to inflict upon the weak. He would have rather swam to the mainland than have to deal with the Master. He placed his hand to his breast, feeling the bursa's presence. Then he raised his chin, formed a steeple with his hands and approached the Master with all the pious energy he could muster.

The Master was berating the young goat herder, 'You'll pay double to cross this day,' he growled. The boy visibly shrank in the big man's shadow, 'But Master, you told me -'

'You pay me double now, before I sail, or you don't go at all,' interrupted the Master.

He didn't see Brother Anselm stood patiently over his right shoulder, not until the goat herder's eyes gave him away. The Master spun around, surprised and clearly flustered by his presence.

'Father, Father Anselm isn't it, I'm...I'm surprised to see you this day,' the Master spluttered.

Brother Anselm, was initially surprised at this response but then a sly smile crept across his lips as it dawned on him and he could have kicked himself for not realising.

'Good day Master,' he said, 'please forgive me if I startled you, it was not my intention.'

The Master looked curiously into Brother Anselm's eyes, 'You do not frighten me Father, far from it.'

Brother Anselm's confidence slackened slightly but he swallowed and dug deep, 'Did I hear correctly? Did I hear you demanding double the normal toll to convey this goat herd to the mainland?'

The Master looked up to the heavens and sighed but before he could reply Brother Anselm continued, 'Aye, double payment I believe you said, would that be because today is the sabbath? I need not remind you of the penalty for working this day, not unless there is dire need. What dire need do these goats have, pray enlighten me?'

The Master turned and looked over at the goats and Brother Anselm was sure of what he was calculating - was it worth it? Brother Anselm held all the cards, if he reported this transgression back to the Abbot, it would cost the Master dearly.

Brother Anselm rubbed his hands together, 'I am on the Abbots business and have dire need to cross to the mainland this day. You will take me now?'

The Master's shoulders dropped, 'Of course Father, I am at your service, allow me to disembark the animals first and we can be on our way.'

Brother Anselm wagged a finger, 'Leave them on board, they might as well cross now,' A satisfied smile erupted on the lips of the Master.

'But you will not charge the goat herder for the journey,' said Brother Anselm, which quickly removed the Master's smile. 'That will be your penance for your wicked transgression,' added Brother Anselm.

The ferry was a broad, ugly vessel, black with tar and older than the Master's temper. It sat low in the water beneath the weight of eleven goats, and it stank. Brother Anselm took the bench nearest the prow, as far from the Master as the boards allowed, and folded his hands in his lap to stop them trembling. Beneath his cassock the bursa pressed against his ribs, a small square of weight no heavier than a prayer, and yet he felt it more keenly with every lurch of the deck.

The goat herder crouched among his animals with his arms around the neck of a speckled nanny. He could not have been more than twelve. When Anselm caught his eye the boy ducked his head, then looked up again, and gave the smallest of nods.

The Master cast off with a grunt and set his weight against the long sweep. The jetty slid away. For a time there was only the slap of water on the hull, the creak of the pole and the muttering of the goats, and the mist closing around them like a curtain drawn across a bed.

'You are young for the Abbot's business,' said the Master at last.

'The Abbot trusts whom he chooses.'

'Does he.' The Master did not turn his head. His great hands moved on the sweep, steady and unhurried. 'And what business would take a boy across the water on the sabbath, with no purse and no companion?'

Anselm had expected the question and had prepared a reply. It deserted him entirely. 'That is between the Abbot and myself,' he said, and was dismayed to hear his voice climb.

The Master laughed 'Aye. Between you and the Abbot.' He spat over the side. 'You have the look of a lad carrying something he is afraid to lose. I have ferried a great many such lads. Thieves, mostly. Sometimes priests.' He turned then, and his small eyes travelled slowly from Anselm's face down to his chest, and rested there. 'Sometimes it is hard to tell the difference.'

Anselm's hand had crept to his breast before he could stop it. He pulled it away as though the cloth were hot.

The Master smiled. It was the smile of a man who had been shown a card and was in no hurry to play it.

The water changed after that. It grew darker, and then restless, and the swell began to lift the ferry and set it down again with a shudder that ran through every plank. The goats bleated. The nanny in the boy's arms rolled her eyes white. Out in the grey, something that might have been a gull cried once.

'Weather's turning,' said the Master. 'It does, this time of year. Comes up from nowhere.' He dug the sweep deeper. 'A heavy boat wants lightening in a sea like this, Father. Everyone knows that.'

Anselm looked at the goats. Then, slowly, he looked at the Master, and understood.

'You would not,' he said.

'I would not,' agreed the Master gently. 'Not goats belonging to a poor boy. Not with a servant of the Abbot watching.' His gaze dropped again to the cassock. 'But a man might think a great deal, in a storm. A man might wonder what is so precious that a boy would cross the mountain in the dark for it. A man might wonder who would ever ask where it went.'

The wind rose, and the first cold spray struck Anselm full in the face. He tasted salt, and under the salt, fear. He thought of Father Thomas leaning against the gatehouse wall with his eyes closed, and the cracked voice that had said into his hands only, and the single word that had followed it. Finished.

He stood. The deck pitched, and he caught the rail and held on.

'I will tell you what the Abbot will ask of me when I return,' he said. His voice shook, but it carried. 'He will ask whether the Master of the ferry served God's work faithfully. And I will answer him truthfully, whatever that answer is.' He swallowed. 'I am sure it will be a short conversation.'

For a long moment the only sound was the sea. The Master studied him. Anselm could not have said what moved behind that broad, filthy face, whether it was calculation or contempt or something nearer to respect, but at last the big man looked away and bent his back to the sweep.

'Sit down, Father,' he muttered. 'You'll go over the side.'

Anselm sat. His legs had turned to water. The speckled nanny, quite unconcerned, began to chew the hem of his cassock.

The storm did not come after all. Within the hour the swell eased and the mist thinned to rags, and a long smudge of green rose out of the sea ahead, the mainland, with the grey roofs of a harbour town huddled at its edge. Church bells were ringing there. They carried faintly over the water, and Anselm bowed his head, feeling the bursa beneath his palm, whole and dry and safe.

It was only when the ferry bumped against the stone quay and the Master threw down the rope that he noticed the boy watching him. The goat herder had drawn very close, his face pale and serious beneath its dirt.

'Father,' he whispered. 'Be careful on the road. He has a brother in the town. A bad man.' He glanced back at the Master, who was busy with the knots. 'I heard them talking last week. They said a priest would come this way carrying a letter, and that there would be silver for anyone who stopped him.'

Anselm stared at him.

'Who said so?' he breathed.

The boy shook his head, frightened now, and slipped away among his animals.