Aelfric comforted Boniface, who seemed exhausted.

Belisarius murmured to Bertgils, 'Your King expresses strong ideas, but with much anger.'

Bertgils nodded. 'And it is always best, Belisarius, not to get in the way of that anger.'

The hall filled up. Belisarius and the others followed Bertgils to their places at the rear, behind the rows of drunken thegns.

The King sat on his throne of stone, with his young wife at his side and his athelings close by, a line of them ranging from children with wooden play-swords to young men and women. German kings still took many wives, despite the best efforts of the priests to suppress such practices.

At length the feast began, with a burst of music from a harp. Servants brought hot meaty broth from the cauldrons hanging over the fire. Others carried in immense plates of meat. The thegns used their own knives to hack at butchered hogs. In their heavy coats and fur leggings they looked like bears, tearing at the carcasses.

The air grew thick with the smoke from the candles and lamps, and the soot from the fire, and the stink of broiling meat. Huge shadows played among the rafters of the tall ceiling. The noise increased until you had to bellow like an ox to make yourself heard.

And the drink flowed like a river. Belisarius sipped only cautiously, striving to keep a clear head. He tried the mead, which, fermented from crushed honeycombs, was very strong; and wine, which was raw and new and too strongly flavoured for his taste.

The ale, which the Germans called beor, was sweet and lumpy, with a consistency like porridge. When the ale came the purpose of the King's wife's silver sieve became apparent. When ale was poured for the King she used her sieve to strain out the grit, which she then dumped on the floor at her feet, where dogs lapped it up eagerly.

The gift-giving began. Belisarius watched curiously as one by one the thegns approached the throne, to be given a gift by the King – and, sometimes, to deliver a gift in turn. The gifts were precious, always jewellery or weapons; often they were bracelets to wear on the arm, a very old custom. And there was no doubt much significance for these jostling courtiers in the value of the gifts exchanged, and the precise degree of warmth of the King's embrace.

These Germans had imported their culture from their homelands. It was a primitive society of kinship, of small communities tied together by blood, with the King bound to his companions by gift-giving and oaths of loyalty. And yet this culture had displaced the sophisticated Roman Britons in a few centuries, and grown until it had sprouted powerful kingdoms. Why, Offa had negotiated with continental emperors and corresponded with the Pope.

But perhaps these petty kings in their wooden palaces had gone as far as they could. Their politics seemed fragile and anachronistic to Belisarius, and in the future their kingdoms might prove more vulnerable than any of those present tonight imagined.

As the level of general drunkenness reached new heights, the singing began. The songs were of the relentless German type, each line split into two halves with two stressed syllables each, just like the Menologium, Belisarius thought. But in their compelling rhythm Belisarius imagined he could hear the slap of oars, the echo of a migration across a cold ocean.

Bertgils leaned towards Belisarius and yelled in his ear, 'These are old songs from the days of the great migration. We mourn our lost homeland. We mourn our ancestors. And for light relief we mourn the shortness of life.'

'You're a cheerful lot,' Belisarius shouted back.

Bertgils grinned. 'We are a people without an afterlife, at least except for those few of us who are successful warriors. We have a lot to be gloomy about.'

'But you're Christian now.'

'There is that,' Bertgils said dryly. 'Belisarius, about this prophecy – I do think we need something a bit more substantial to take before Aethelred and the witan. For instance, if this threat of "dragons" is real – where is it to come from? Aethelred knows all about the other German kings, and the Picts to the north, and the British to the west.'

Belisarius mused, 'It might come from another direction altogether.' He turned to the computistor. 'Boniface, speaking of the Menologium, what of the later stanzas – which presumably describe a further future? For instance, that business in stanza seven of how the dragon will fly west. What lies west of Britain? There are legends, centuries old, of lands to the north called Thule – could there be any truth in such a tale?'

Macson was dismissive. 'Everybody knows there is nothing to the west but ocean.'

'Actually that isn't true,' Aelfric said. 'The monks have found that out.'

'How?'

'By sailing there.'

Over the centuries some monks, emulating Cuthbert, in search of ever deeper solitude, had set off on eremitic quests into the western sea. They journeyed from Lindisfarena, its parent house on Iona, and monasteries in Ireland, sailing in fragile little boats of wood and leather called currachs. Many of them failed to return – but some did, telling of lands they found scattered across the face of the ocean.

Boniface said, 'This went on for centuries. And there grew among the monks a tradition that somewhere out there to the west was to be found the Promised Land of the Saints. And so they went further and further.'

This culminated in the seven-year voyage of Saint Brendan, founder of many monasteries, who was supposed to have sailed west to an island of sheep, an island of birds, an island of fire, an island of grapes. He came to a pillar of glass that rose out of the sea. He found the apostle Judas sitting on a rock. And so on.

'What rubbish,' Macson said.

'But Brendan returned to tell the tale,' Belisarius said. 'Clearly he found something.'

Bertgils asked, 'What are you getting at, Belisarius?'

'The Menologium talks later of sea voyages. What if the threat is to come, not from the land, but from the sea? None of your kings is looking that way.'

'But who would come?' Bertgils asked. 'The Franks? Offa is on good terms with them. And the ocean is a hard road to travel.'

'Your people came raiding once, across the ocean,' Belisarius said evenly. 'The Romans did before you.'

'But that was centuries ago. Everything is different now. Look around you. Northumbria is strong – no fool would come here. And besides we would have the support of Mercia. No, Belisarius, this is an interesting speculation but there is nothing in it.'

The Butcher spoke, and the hall fell quiet. 'I can't hear you singing, Father Pretty-face!'

Boniface stood uncertainly, his tumour livid in the lamp light. 'I'm afraid I don't know your songs, King.'

'Then let's hear one of yours.'

Boniface flinched, but all eyes turned to him. 'Very well. This is a hymn of midsummer, composed by Dom Caedmon of-'

'Get on with it!' shouted a thegn, and a chicken bone came whirling out of the air.

Boniface flinched, but he began to sing. His clear voice, smoothed by a lifetime of chanting, delivered a simple, sweet, lilting song in German, of the month of June, in which John the Baptist was born, and the apostles Peter and Paul had suffered martyrdom.

The catcalls began after only a few lines. And as the bones and lumps of bread began to fly, Belisarius got to his feet and put his arm around the frail monk, sheltering him from the greasy storm. 'Get him out of here,' he murmured to Aelfric.

Aelfric led the bewildered Boniface away.

The Butcher was angry and mocking. 'Where's my little monk? I want to hear him sing!'

'Perhaps, my lord,' Belisarius said smoothly, 'you would prefer to hear a song from my own country.' And, without waiting for agreement, he launched into a gloomy old lament of a refugee from Rome, on the eve of its terrible sacking by Alaric the Goth. "'Great were the cries of the maidens of Rome… Even the statues of the forum shed marble tears…"' He did his best to translate the lyrics into German; the scansion was terrible, but he doubted this audience would care about that.