'You know, Sir John, if we find nothing this afternoon then I agree, we should record verdicts of suicide and murder and leave this matter alone for we are making little progress.'

He heard a loud crash behind him. Cranston had placed the wine cup and jug beside the bed, collapsed on to the mattress and was smiling beatifically at the ceiling, fast asleep. Athelstan sighed, went over, and with great difficulty arranged Sir John's huge body more comfortably on the bed. Then he sat beside him. He had not brought his writing tray or materials but mentally he went through each of the deaths he had investigated, trying to fix a pattern, with little success. Cranston snored gently like a child, muttering now and again and smacking his lips. Athelstan grinned as he heard the words 'Refreshment' and 'Some cups of sack!' Sir John burped noisily, rolled on one side and, if Athelstan had not been there, would have fallen completely off the bed. Athelstan let the coroner sleep. Why not? After all, there was only one painting which fitted the texts and that held nothing. His thoughts strayed to Benedicta. Was she missing him? Why had she talked so easily to that nobleman? Were all women like that? Had he done wrong in inviting her in the first place?

He picked up the wine cup and sipped from it and then sat on the bed next to Sir John, staring down at the great wooden bed posters. He dozed and was about to fall asleep when suddenly he woke with a start. The carvings! Especially the one on the right… He got off the bed and went around. Whoever had constructed the bed post had created a vivid scene. The serpent carved there seemed to writhe, its tongue darting, whilst its intended victim, Eve, stood like the personification of innocence with one hand covering her groin, the other raised to hold back her long flowing hair. In between them was the drooping branch of an apple tree. Even in wood the fruit seemed full and lush. Athelstan stood for a moment in disbelief, then he moved over to the other bed post: there, in the centre, the artist had etched a life-like horse. The dark brown of the wood made the creature seem real, one leg raised, head arched, and on its back a frightening, ghostly figure with a hood. Peeping out from beneath it was the skeletal face of Death itself. Athelstan gasped with excitement and went round to rouse the coroner.

'Sir John! Wake up!'

The coroner moved, snored and smacked his lips.

'Sir John!' Athelstan slapped him gently on the face. The coroner's eyes opened.

'My dear Maude…"

'I am not Maude!' Athelstan replied sharply. 'Sir John, I have discovered something.'

'A cup of sack?'

Athelstan refilled the goblet and held it to the coroner's lips. 'For God's sake, Sir John, wake up!'

The coroner sat up, shaking the sleep from his eyes, and stared blearily round.

'For God's sake, Friar, what has happened now?'

Athelstan showed him. At first, his mind dulled with sleep and wine, Cranston stared blankly but the significance of the friar's discovery gradually dawned on him. Without more ado, the coroner began to finger the carving of the figure of Death, probing and pressing it.

'There must be a secret compartment. I have heard of such in the Italian mode, built into chairs, tables and desks. I have even heard of hiding places in beds but never seen one.'

Their search was fruitless so they moved to the other bed post. They pushed different parts of the carving but nothing moved. Suddenly Cranston looked up and nudged Athelstan.

'Look, Brother!'

Athelstan stared across at the bed post where a small block of wood on which the carving had rested had now opened outwards like a door.

'The mechanism must be in this bed post, with a spring that runs here under the boarding and up into the other.'

Again they pressed, watching the small door close when Athelstan pushed the apple between the serpent and Eve. He pushed and it re-opened. Slowly they approached the cavity, each trying to control his excitement. Athelstan put his hand gingerly into the small, dark space and brought out two rolls of parchment. He ignored Cranston's excited pleas to hurry and went over to the window, unrolling them carefully. The first was a love poem written in a rough hand in Norman French. At first Athelstan thought it was addressed to a woman but realised it was written to a young man. He handed it over to Cranston.

'Make of that what you wish!'

The second was a small indenture or agreement. The top was perforated, so someone else must have a copy. Athelstan read and knew why John of Gaunt, Duke of Lancaster, was so indebted to Sir Thomas Springall, and why the merchant had possessed secrets which could have brought him even greater wealth. Cranston had already dismissed the poem, but when he read the indenture he sat at the foot of the bed stupefied, the parchment held loosely between his fingers.

'This was written fourteen months ago,' he said quietly. 'As the Black Prince, father of the present king, lay dying. If the Lord Edward had known this, he would have had John of Gaunt's head on a pole on London Bridge. If it was revealed now there would be a public outcry.'

'So we know the reasons for SpringalPs death,' Athelstan said, 'but not the hows, the wherefores, and above all the culprit or culprits. Look, Sir John, let's follow the method of the Schools at Oxford. You sit on the bed, I'll sit beside you. You will recite everything you know about each of the four murders, beginning with Sir Thomas Springall's. Though in fact there was another killing, making five in all.' He pointed to the parchment poem. 'The young boy who died here must also be regarded as a victim.'

And so they began, Cranston occasionally pausing for refreshment as he recited in an almost sing-song voice what they knew about Springall's death, and then Brampton's, Vechey's and Allingham's. Athelstan would correct him and make Cranston repeat the list of facts time and again until the coroner, not famous for his patience, shouted: 'Hell's teeth! What are you doing, Brother? We are wasting time! All we are doing is repeating what we already know.'

'Be patient, Sir John,' Athelstan replied, 'Remember, we are looking for a pattern. In logic when you have a problem, the very words of the puzzle contain the answer. There must be a pattern in each of the murders.' He saw Sir John set his mouth and glare from beneath bushy grey eyebrows. 'Look, there is one murder we know very little about – Vechey's. But three, Allingham's, Brampton's and SpringalPs, we do. There must be common factors, things which link all three. We have already established one: poison. I also suspect Vechey and Brampton were drugged. They would not have allowed people to pluck them up, take them prisoner, tie a noose around their necks and kill them. So we have some matching strands. Let us see if there are more.'

Once again Sir John grudgingly recited the facts they knew. Outside the day drew to a close. Athelstan, now listening with half an ear to Sir John's recitation, looked out of the window and wondered what had happened to Benedicta and Lady Maude. Should they return to escort the ladies? He broke Sir John's concentration by asking but the coroner just glowered.

'The Ladies Benedicta and Maude are well able to look after themselves,' he said. 'You started this, Brother, so we'll see it through to the bitter end. Moreover,' he smiled, 'I asked the young gallant who was sitting by Benedicta to take care of both ladies. I am sure he will.'

Athelstan ground his teeth and glared at the coroner but Sir John smiled sweetly back as if innocent of any devious stratagem. Athelstan again made him repeat all they knew, though this time excluding Sir Thomas Springall's murder. Then he walked over to the window and stared down at the chess board. Absentmindedly he began to count the squares, and his heart quickened.