They lifted the young woman’s corpse and laid it gently out on the bed, crossing the hands. Sir John opened his purse and put two pennies over the eyes.

‘Leave me.’ Sir Walter forced a smile, but there were tears in his eyes. ‘Leave me for a while. You have business with those demons below.’

‘Stay with Sir Walter,’ Athelstan asked Aspinall. ‘Sir John, Sir Maurice, we should go down.’

They returned to the hall and told the Frenchmen what had happened. De Fontanel quickly crossed himself. The prisoners, huddled together, looked frightened.

‘It’s not safe to leave us here.’ Vamier spoke up. ‘Sir Walter is our enemy already. He will blame us for his daughter’s death.’ He banged the table with his fist. ‘I demand to be removed! To be given safer and better custody than this!’

‘I can arrange that.’ Sir John took a seat, tapping his hands on the table-top.

Athelstan sat down and took out his writing tray. He opened the ink pot, dipped the quill in but simply scratched the parchment, making strange signs and symbols. He had little to write; there was nothing about this affair which made sense. He glanced across at Sir John.

‘Semper veritas,’ he murmured. ‘Always the truth. Perhaps it’s time we were blunt and honest and told these gentlemen that they are, truly, in mortal danger but not from Sir Walter. Indeed, if we removed them elsewhere, or advised the Regent to change their keeper, it would look as if the finger of accusation were being pointed at Sir Walter.’

‘He is, as you correctly say,’ de Fontanel drawled, ‘their keeper. He is responsible for their safety. I am truly sorry his daughter died but Vamier does speak the truth, Limbright is our enemy.’

‘Tell me, gentlemen.’ Sir John looked down the table at the three prisoners. ‘Have you ever heard of Mercurius?’

Athelstan studied their faces. Was that a flicker of recognition in Gresnay’s eyes?

‘Mercurius?’ de Fontanel sneered. ‘Who is Mercurius?’

‘He’s an assassin,’ Athelstan replied slowly. ‘Employed by the French Crown. He kills people whom his masters in Paris want removed as quickly as possible. Do you know, sirs, you are probably safer in England than you are in France.’

‘Don’t talk in riddles!’ Gresnay snapped.

‘Mercurius is an assassin,’ Athelstan repeated. ‘The French believe the St Sulpice and St Denis were betrayed by an officer on one of those two ships. We think, indeed we know, Mercurius is in England. His task is to kill the traitor among you.’

‘In which case,’ Maneil replied guardedly, ‘he has killed two.’

‘No, no.’ Gresnay spoke up. ‘I realise what you are saying, Brother. Mercurius doesn’t really care how many of us die.’

‘As long as the traitor dies,’ Athelstan declared, ‘that’s all that matters. Sentence of death has been passed against you.’

‘But who?’ Vamier sprang to his feet. He gripped Gresnay’s shoulder. ‘Is it you, Jean?’

‘What do you mean?’ Gresnay squirmed free.

‘Vamier’s telling the truth,’ Maneil said. ‘You were once a clerk! You’re always boasting about your high-ranking connections in Paris.’

‘And what about you?’ Gresnay countered. ‘Didn’t you get preferment to the St Denis because of a relative at court?’

‘This is preposterous!’ De Fontanel got to his feet and walked down the table, sitting down next to Vamier. ‘Sir John Cranston, I am an accredited envoy, a high-ranking clerk of the chancery. I have never heard of this Mercurius. I think you are trying to divide these men, frighten them into making confessions, make them watch each other.’

‘It would certainly help,’ Sir John said as he smiled back. ‘If they watched each other more closely, perhaps they could discover the murderer?’

De Fontanel laid his hands on the table, spreading his fingers.

‘Five men were here,’ he replied slowly. ‘Two are dead of the same poison but they only ate and drank what the others did. True, Serriem may have been tricked but Routier was alert to any danger. And why should Mercurius kill that poor girl who was a danger to no one? Don’t you agree, Brother?’

Athelstan raised his eyes heavenwards. The murder of Sir Walter’s daughter threw all these theories back into the melting pot.

‘It could be an act of vengeance,’ Sir Maurice said.

‘Oh, come, come!’ Vamier snarled. ‘Sir Maurice, I would like to take your head and that of Sir Walter. We are soldiers, fighters. Why should we kill a poor wench? She had a woman’s body but a child’s mind.’

‘Which is due to the French,’ Sir Maurice added quickly.

De Fontanel got to his feet. ‘I am not here to trade insults. Sir John, what are you going to do about the custody of these men?’

‘They are going to stay here. Brother Athelstan, my secretarius, is correct. If they are taken elsewhere and Sir Walter is relieved of his duties, distraught though he is, that would look as if he were under suspicion.’

‘In which case I shall send urgent despatch to France asking for the ransoms to be forwarded as quickly as possible. I ask my fellow countrymen to fall to their prayers and recite their Aves daily and be very careful of what they eat or drink.’ He bowed. I shall return.’

His footsteps echoed along the gaunt, empty hallway, the door slamming shut behind him.

‘We are finished here,’ Athelstan said. ‘There is nothing more we can do except speak to Aspinall. The business of Vulpina,’ he added in a whisper.

Sir John nodded and, followed by Sir Maurice, left the hall. Athelstan sat sketching two parallel lines on a piece of parchment.

‘You seem perplexed.’ Vamier’s tone was kindly.

‘There is great evil here,’ Athelstan replied slowly. I am right to call this the Devil’s Domain.’

‘I know of your Order in France,’ Gresnay said. ‘My father hired a Dominican as a chancery priest, a kindly man. Is there nothing you can do for us, Brother?’

Athelstan shook his head. ‘Nothing. At least for the moment. Tell me now, on your oaths. Forget I am an Englishman, think of me only as a priest. Tell me, is there anything you saw or heard which provoked suspicion?’

The three men sat in silence then, one by one, shook their heads.

‘Your two colleagues who have been murdered, you saw neither of them eat or drink anything extra?’

Again the shake of heads.

‘Or did they say anything to you?’

‘Brother.’ Maneil spoke up. ‘We have been down the same paths ourselves. We have no food or drink in our chambers. All our sustenance comes from Sir Walter’s kitchens, paltry though it may be.’

‘Does de Fontanel bring food?’

‘Never. Sir Walter would not allow it.’

‘I tell you this.’ Gresnay pointed a finger. ‘Yesterday morning we all took a solemn oath not to eat or drink what another didn’t. We also searched each other and the shabby garrets which serve as our chambers. Nothing was found.’

‘You did that?’ Athelstan asked.

‘Brother, a killer stalks us. We have to be sure.’

Athelstan got to his feet.

‘One thing does intrigue me.’

‘What’s that?’ Vamier asked.

‘Well, Routier escaped this morning. He climbed the garden wall, crossed the yard and went through an outhouse. How did he know which path to take? How did he know that the outhouse was deserted, that the shutter was loose? You have never been allowed into that part of the manor, have you?’

All three shook their heads.

‘Then I bid you good day, sirs.’

Athelstan left the hall and wandered out into the garden. He looked up at the parapets and realised that, if the sentries were less than vigilant, it would be easy for someone to cross the corner of the wall and climb the crumbling buttress. He now did this and let himself down the other side. The yard or bailey was deserted. A slight breeze was blowing up little clouds of dust. Built alongside, into the far curtain wall, were a line of wooden outhouses, probably used for storage. Athelstan crossed over and went in. Most of the doors were closed. Athelstan went through the one which hung ajar. Inside the walls were dirty and cobwebbed, and there was a smell of straw and horse manure. In the far wall the shutters were closed and barred. Athelstan lifted the bar, opened the shutters and looked out across the sun-scorched heathland. He put his bag down, climbed out and began to walk, following the same path Routier had probably taken. He stopped and looked about him. Above him a crow circled, cawing raucously. Athelstan saw that there was no sentry on the rear wall while those along the side must not only have been lax but distracted by the supposed quarrel taking place among the prisoners. Routier would have run, heading for that distant copse of trees. Even if the sentries had glimpsed him they might have thought it was some chapman or peasant, not realising one of their prisoners had escaped. He looked back at the window whose shutters still hung open. Routier had probably closed them when he fled. Athelstan scanned the sky.