‘It may have even caused Mahant’s death,’ he murmured immediately after taking the oath.

‘What?’ Cranston sat up in his chair.

Athelstan stopped writing.

‘Yesterday evening,’ Wenlock wearily explained, ‘Mahant came to my chamber. There was a platter of sweetmeats, just three or four left. I offered some to Mahant but he refused. I was hungry and ate them all. We were discussing Osborne’s death. I began to feel sick. I vomited into the jakes pot. Mahant believed, and so did I, I still do, that the sweetmeats were poisoned or tainted. Mahant began drinking. He grew hot against Richer. He blamed the Frenchman for all the ills which had befallen us. He cursed him.’ Wenlock paused, fighting back the urge to retch. ‘He vowed to confront Richer, make him pay for what had happened. I thought it was the wine talking. By then I did not really care, I was vomiting so much. Mahant asked if I wished to go to the infirmary, I said no and he left. I stripped off my clothes, put on my nightshirt and lay on the bed.’ Wenlock paused. ‘God assoil him, that’s the last time I saw Mahant alive. I woke in the early hours, my belly raging like a bubbling pot. I was freezing to death. I left my bed, put on a cloak, went down to the infirmary and hammered on the door to speak to the infirmarian. He made me drink water with some herbs infused. I fell asleep there, not waking until the tocsin sounded.’

‘You feel better?’ Athelstan asked.

‘Certainly, the retching has stopped.’

‘And you never saw Mahant after you fell sick?’

‘No.’

‘Do you have any explanation why his corpse and that of Richer should be found in the hog sty?’

‘Brother Athelstan, I wish I did.’ Wenlock clutched his stomach. ‘Perhaps he and the Frenchman confronted each other.’

‘In that place, in the dead of night?’

‘Brother, I wish I knew.’

‘Were you and Mahant planning to leave St Fulcher?’

‘Of course. We had already moved some of our possessions to “The Pride of Purgatory” tavern. We were also preparing to petition His Grace for safer lodgings. We invoked the memory of his blessed brother the Black Prince. Can you blame us?’ Wenlock insisted. ‘We’d become no better than hogs for the slaughter here.’ He smiled at his own grim joke. ‘Sir John, Brother Athelstan, if you’ve finished. .?’

Cranston let him go. The infirmarian was summoned but he could add little. He confirmed Wenlock’s story. As regards to the two most recent murders, he explained how both corpses were so badly mauled it was impossible to determine what had happened. The royal serjeant, captain of the archers, came last. He reported how the hogs had been slaughtered and, following Cranston’s order, both the sty and the pen had been scoured for any items but they’d found nothing. He left, followed by Brother Simon. The abbey church fell silent.

‘So?’ Cranston asked.

Athelstan rose, collecting together his quill pens and scrolls of soft vellum.

‘One last person.’

Cranston followed Athelstan down to the anker house. They heard movement within, a shape moved. The anchorite looked out, shifting to get a better view of Cranston.

‘I know what has happened. Now you have come down to question me. Sir John, I believe we have met. I shall never forget-’

‘Agnes Rednal.’ Cranston came up close to the anker slit. ‘You and I have hanged London’s worst.’

‘And the kingdom is the better for it.’

‘Agnes Rednal,’ Athelstan intervened. ‘She will never visit you again.’ He peered through the slit. ‘I assure you. I have laid that demon. She will only walk in your nightmares, though a prayer before sleep should take care of that. Look, why not come out and greet Sir John?’

‘Brother Athelstan, I have left my cell enough over the last few days. I have nothing to say about these dreadful slayings. The church is locked an hour after compline, I cannot leave. I saw nothing. I heard nothing. .’

Athelstan touched Cranston on the arm. They strolled back up the aisle.

‘I wonder,’ Athelstan whispered.

‘About the anchorite?’

‘Yes. Those grievances he nursed against the Wyverns, though nothing against Richer or so I believe. I just wonder why he would not allow us into his cell or come out of it. Does he have something to hide? As for leaving this church, he could always creep out through the charnel house.’

Cranston and Athelstan cleared the judgement table and walked out into the Galilee porch. The friar stared up at a carved stone boss displaying a demon with a grinning monkey’s face.

‘Enough is enough, Sir John,’ he declared, ‘all this questioning must end. I’ll retire to my chamber and study the “Liber”. I must discover why Richer wouldn’t show it to me. You, my learned friend, are always welcome provided you let me share some of your refreshments.’

Back in his chamber Athelstan placed the original ‘Liber’ on the table and carefully scrutinized the different chapters. He soon realized the bloodstone was a very precious relic. The ruby’s history stretched from its formation to its collection by Joseph Arimathea and its long journey round the ancient Roman empire until it passed into the hands of the early popes. The history was disappointing. However, when Athelstan began to read about the alleged power of the bloodstone, the punishments inflicted on those not worthy to handle it as well as its miraculous curative powers for those who regarded it as a sacred relic, Athelstan’s heart skipped a beat. The ‘Liber’ proclaimed powerful warnings against any sacrilegious handling; little wonder Kilverby changed. Indeed the ‘Liber’ explained why Richer was so zealous in pursuing the bloodstone’s return, his hatred for the Wyverns and his influence over William Chalk. The defrocked priest must have come to view his own painful, lingering disease as a just punishment from God for what had happened in France. The list of miracles also made Athelstan think and reflect deeply. Eventually the friar prepared his pen and ink pots, smoothing out a piece of vellum after staring distractedly at a finely drawn triptych celebrating the life of St Benedict’s sister, the holy Scholastica.

Once he had collected his thoughts, Athelstan began to construct a logical argument. Kilverby’s murder was relatively easy. Athelstan’s hypothesis was that when the merchant died he must have known the bloodstone was safe. It was logical. Kilverby held the bloodstone. He sat in his chamber for sometime before he died yet he did not raise the alarm or express any anxiety about it being missing. Athelstan developed this argument then returned to fill in the gaps. On one occasion the friar left going through the now silent abbey to check the records in the muniment room behind the chapter house. No one objected. Divine office remained suspended until matins the following morning whilst the good brothers had been truly overawed by Cranston’s display of power. Athelstan’s queries and questions were soon answered and he returned to his studies. He finished what he called his Kilverby thesis; a few minor gaps remained but Athelstan believed he had enough to hoodwink then trap the killer.

The friar pulled across a fresh piece of parchment and began what he entitled ‘The Abbey Thesis’. He listed the murders beginning with those of Hanep and Hyde. He could now explain these, then he turned to Brokersby’s. He scrutinized earlier notes and found the entries he was searching for. Osborne’s death was relatively easy to explain whilst the logic behind that also accounted for the murders of Mahant and Richer. Nevertheless, though he had the bricks to build, the mortar and cement were a little more difficult to find. There were gaps which had to be filled: the chasing, flitting shadow which had pursued Hyde; the mysterious crossbow man: the ugly incident in the charnel house: a proper, logical account of Richer and Mahant’s death and how they were overcome and killed by the same assailant. Athelstan kept working on his hypothesis. Cranston knocked on the door and brought in a platter of food and some ale. Athelstan ate and drank, absent-mindedly fending off Cranston’s questions until the coroner, muttering he might as well be singing to the moonbeams, left for his own chamber. At last Athelstan made his decision. He crossed himself, rose and went out and knocked on Cranston’s chamber. The coroner was already preparing for the night.