'There is a pattern, Sir John,' he said softly. 'Yes!' He turned, his lean face bright with excitement. 'There is a pattern!'

'You know who the murderer is, don't you? Come on, you bloody friar!' Cranston roared. 'Tell me! I haven't sat here on this bed like a boy in a schoolroom reciting lists of facts for nothing!'

'Tush, Sir John, patience,' Athelstan replied. 'Let me work it into a pattern. Let me get the proper sequence of events, then I shall tell you what I know and the problem will be resolved. But for now you stay here, examine the indenture, reflect on what you have said. I won't be long!'

Before a bemused Cranston could reply, Athelstan had slipped out of the room, walking gingerly across the noisy Nightingale Gallery, down the stairs and out into Cheap- side. Just in case he met any of the Springall household he went down Friday Street, turning into Bread Street and back up St Mary Le Bow. The church was open. Athelstan went into the nave and sat at the base of a pillar, legs crossed, whilst he stared up at the high altar behind the rood screen. He looked round the cool, beautiful church, at the frescoes on the wall, lectern, and pulpit of exquisitely carved oak. From the stalls in the sanctuary he heard the master assembling the choir, rehearsing the hymns and canticles for the feast of Corpus Christi. Athelstan leaned back, letting his head rest against the coldness of the pillar whilst he stared into the darkness, trying to rearrange what he knew, to make the pattern complete and trap the murderer. This was one occasion when the sons of Cain, the killers, would not turn round and claim with mocking innocence, 'Are we our brother's keepers? We are not responsible because we are innocent,' while the blood of five human beings stained their hands and darkened their souls.

The choir began the beautiful hymn 'Pange Lingua'. Athelstan let his mind and soul be calmed, moved by the rhythmical chanting. At one point the youngest boys, the choir's sopranos, took up the refrain, pure and lucid, filling the entire church with angelic sound.

'Respice. Respice Domine. Look back, oh Lord, look back on us! '

Athelstan muttered the words under his breath. 'Look back, oh Lord,' he prayed. 'Give me wisdom and light. Let me plumb the darkness, root out the wickedness. Let those things that were done in the dark of night be revealed for your justice and that of the king in the full light of day.'

Athelstan meditated for an hour. He saw the irony that here he was in a church, the house of God and gate to heaven, thinking about murder. But gradually the pattern was resolved. The culprits were identified, their motives revealed, and he reluctantly admired their deviousness, the sheer wickedness of their plan. He built his own traps, hedging them about, and, when he was ready, returned to the Springall house.

He found Cranston still resting on Sir Thomas's bed, a cup of claret in his hand, softly singing a lullaby. Athelstan could have sworn he was acting as if there was someone else there. As if he was singing to someone he loved. The friar noticed the coroner's eyes were brimming with tears. He looked away, pretending to stare out of the window as he began to summarise his conclusions. Behind him, Cranston regained control of himself. He listened to the friar describe the motive and the identity of the murderers. At first, the coroner rejected everything his assistant said.

'Too ingenious!' he cried. 'Too clever! Too diabolic!'

Athelstan turned.

'Diabolic, yes. But these murders were crafted in the human soul and decided upon by the human mind even if carried out for malicious, devilish purposes. I think I speak the truth, Sir John.'

Cranston stared moodily down at the floorboards, scuffing his boots over the polished surface. Suddenly the Nightingale Gallery outside creaked and sang. Cranston's hand went towards his dagger and Athelstan rapidly approached the door. It was only the old servant, deeper in his cups than Cranston. He staggered and leaned on the door post.

'You have been here a long time, masters. Are you staying? Waiting for Sir Richard?'

'No,' Cranston replied, 'I have told you already. We are here on the regent's orders!' He lifted the wine cup and drained it. 'But I do thank you for your hospitality, sir. I shall remember it.'

'Oh,' Athelstan added, 'is it possible that I could speak to one of the laundresses?'

The servant looked surprised. He blinked but agreed, and some time later ushered a scared girl into the room. She became even more frightened as Athelstan outlined his request and asked her to bring the napkin as soon as possible. When she did Athelstan poured the dregs of the wine over it, cleaned a dusty part of the room and put it beneath his cloak. The maid servant quickly left. Sir John looked bemused.

'What I have done is vital, Sir John,' Athelstan assured him. 'It may well trap the murderers.'

They left the deserted house, the old manservant locking the door behind them, and went down into a deserted Cheapside. Black rain clouds were scudding in over the Thames. It was dark and some of the merchants had lit the lantern-horns outside their doors, whilst Athelstan glimpsed the beacon light shining red and full in the steeple of St Mary Le Bow. They made their way down Friday Street, Old Fish Street and into the Vintry, and hired a wherry at Queenshithe Wharf to take them along the choppy river to the Savoy Palace. Viewed from the river bank John of Gaunt's palatial residence looked magnificent, and even more so tonight with the festivities going on. The windows were lit by the flames of thousands of beeswax candles and, as they approached the main entrance, they heard faint strains of music, chatter, and the sounds of merriment. A burly serjeant-of-arms stopped them, asked their business, and grudgingly let them through into the main courtyard where they were halted by a steward who took them up into the main hall.

Athelstan was dumbfounded by the magnificent spectacle awaiting them: the hall was long, the hammer-beam roof high, whilst every piece of woodwork and stone was covered in the most luxurious velvet and samite hangings, gorgeous banners and hangings of every hue. Down the hall on each side were long trestle tables covered in the costliest silk. Every few feet were huge eight-branched candelabra, each with its own beeswax candles. Above them in the loft the musicians played, though their music had to compete with the noise of the revellers sitting at table.

At the far end, on the dais, Athelstan glimpsed John of Gaunt. On the same table he saw the young king, Chief Justice Fortescue, and some of the leading nobility of the realm. At the table just beneath the dais, running parallel with it, they saw Sir Richard Springall, red-faced and deep in his cups. At his side was Lady Isabella who for that day had cast aside her mourning weeds and wore a pure gold dress with matching veil. Father Crispin and Master Buckingham were also visible, while at the other end of the table were Lady Maude and Benedicta, between them the young nobleman who had made his intentions so blatantly obvious earlier in the day. Lady Maude was looking down the hall, obviously looking out for her husband. Benedicta, cooler and more composed, was listening attentively to some story the nobleman was telling her, though now and again moving slightly away from him as if she had come to resent the young gallant's attentions. The steward was about to announce them but Athelstan put a hand on his arm.

'No,' he muttered. 'Not now. The feast is in progress.' He looked down at the tablecloths splattered with grease and wine, the platters now cleared. The servants were bringing in bowls of fruit, junkets of cream, plates of thin pastries, sugar-filled doucettes, and jellies formed in exquisite shapes of castles, swans and horses. Soon the banquet would be over. He looked at Sir John.