Cynewulf said slowly, 'I think I know a way.'

Arngrim said, 'You mean your prophecy.'

'Yes.' Seeing Arngrim's sceptical expression, he said quickly, 'Think about it, cousin. Aebbe has told me damnably little about this vision from the past. She always knew it was her sole bit of power. But what she did tell me was tantalising. "Even the dragon must lie/At the foot of the Cross." What can that prophesy but the triumph of Christ over the pagans-and what Christian king can lead us but Alfred? For if he falls, there will be none to follow.'

Arngrim scowled. 'How do you know this has anything to do with our century at all? Perhaps this verse speaks of the dead past, or the far future.'

'No,' Cynewulf said. 'The prophecy contains specific dates, tied to the appearances of a comet – the calculations are difficult. I know it speaks of now, cousin. I am sure of it.'

'So you say. Even though you can't work out these dates for yourself.'

Ibn Zuhr said, 'I would be intrigued to hear your prophecy. I know a different way of figuring, more advanced than yours. Perhaps I could interpret the dates for you-'

Arngrim ignored him. 'The trouble is,' he said practically, 'we don't have Aebbe. The Danes do, and they are intent on taking her to Eoforwic, where they will sell her, body, soul, prophecy and all.'

Cynewulf clenched his small fist. 'Then we must find her, and bring her back. If it means we must travel all the way to Eoforwic – well, that's what we will do, for we must give the King hope. Are you with me, cousin?'

Arngrim was reluctant. He felt he should stay here; his instinct was to fight. There was talk of finding ways to use this marshy base to strike back at the Danes. But if the King could not be revived from his scholarly torpor, perhaps there would be no fighting at all. He said reluctantly, 'I don't have any better idea.'

Ibn Zuhr, an outsider in this drama of kin, kingship, religion and culture, smiled to himself. 'Tell me – what oracle is the author of your prophecy?'

'It is said to be a Weaver. An emperor of the future who sees all history, like the pages of an open book.'

'Perhaps we should consider why he would want Alfred to prevail.'

These strange words, quietly delivered, made Cynewulf shudder, unaccountably.

Arngrim requisitioned horses, stout travelling clothes and a few purses packed with silver. Early one February morning he, Ibn Zuhr and Cynewulf set off to cross England to the Vikings' greatest city.

Avoiding the Danes at Cippanhamm they headed east across a countryside still locked down by winter, and they met few people on the road. This may have been a country at a pivot of its history, but almost everybody in England worked on the land, and January and February, when you could venture out at all, were months for ploughing and pruning, for eking out last year's stores, for preparing for the spring, not for travelling. They developed a habit of setting off before dawn and riding until after dark, with Cynewulf fretting at the shortness of the midwinter days. Ibn Zuhr negotiated places for them to stay each night, where their horses could be stabled or exchanged. The German tradition of hospitality had survived even in these times of raids and invasion, but Ibn Zuhr was always careful to approach any dwelling cautiously, his cloak thrown back to show he had no weapons drawn, and with a blast on his horn well before he came within bow-shot.

During the journey Ibn Zuhr asked more questions about the prophecy. Though Cynewulf didn't have a copy of the Menologium itself he did have fragments of analysis of it, much of it by a long-dead monk called Boniface, whose commentary had been rescued from the ruined library of Lindisfarena. Ibn Zuhr read all this avidly, but if he came to any conclusions he kept them to himself.

They came to the town of Snotingaham, at the heart of Mercia. The great Offa's kingdom was now ruled by a Danish puppet-king, much of it colonised by Northmen and their families. Snotingaham itself was under the thumb of the Danes, but the English went about their lives mostly unperturbed.

Here, Amgrim sought out a friend of his called Leofgar.

Leofgar was a burly, jovial, prosperous-looking man with a livid scar painted across his face. His hair was a woolly mass as black as night; Cynewulf wondered if he dyed it.

Leofgar clapped an arm around Arngrim. 'We're old buddies,' he said to Cynewulf. 'We fought together against the Danes a decade ago, when they took Snotingaham and holed up in it, and the West Saxons came to help us out.' He touched the scar on his face. 'We couldn't get rid of the Danes back then, but I took away a trophy, as you can see – that and the life of the Danish brute who gave it to me.'

Since his fighting days Leofgar had become a weapons dealer. And from the look of his fine cloak and jewellery, a decade of war with the Force hadn't done business any harm. Cynewulf wondered cynically if he had any qualms about selling weapons to both sides.

Arngrim said this formidable man was to be their guide for the rest of the journey through Northumbria to Eoforwic. They needed him, for as everybody knew the Northumbrians were a rough lot, and had been even before the Danes came and killed their kings.

They were treated to a heavy night of eating and drinking at Leofgar's home. Then they woke before dawn as usual. With banging heads and growling stomachs, led by Leofgar, they resumed their long journey, progressing into the bleak, hilly country of Northumbria.

The Northumbrians' uncouth accent was all but incomprehensible to Cynewulf. They were a sour bunch who resented their British neighbours to the north, and the English kingdoms to the south, and their new Danish overlords in Eoforwic. They didn't even much like each other, and given half a chance they would be at each other's throats pursuing ancient grievances once again. And they drank prodigiously. In their cups they would sing long mournful songs about the great days of Kings Edwin or Oswald or Oswiu, before they fell to puking, fighting, humping, or all three.

'And that's just the monks,' as Arngrim said dryly.

But even among these dour folk change was apparent. Quite unconsciously, they laced their speech with Danish words.

There was another difference. Markets studded the countryside: small places, not towns, springing up at crossroads or river crossings, anywhere convenient. They were just huddles of stalls and booths where you could buy salted meat and winter vegetables, and bits of clothing, shoes, knives. There were even, strangely, bits of jewellery to buy. Cynewulf had only ever seen kings, thegns and bishops and their ladies sporting jewellery; here even humble peasants wore glittering clasps and shoulder-brooches.

All this was more change brought by the Danes. Before the invasions England had been fragmented into vast estates, with a river or two for transport and for fishing, some good lowland for ploughing, hill country or moorland for the sheep, and so on. The estates were like miniature countries, contained in themselves. And you expected to spend your whole life on your estate, tied by bonds of loyalty and tax duty, and you would barter and spend at the estate's own markets.

Now the Danes were sweeping all this away. The Danish warriors, parcelling up the countryside, were farmers themselves. But their holdings were smaller, and whatever they couldn't supply themselves they traded for: fleeces for timber, perhaps, or horses for hops. Suddenly trade was exploding across England in a network of tiny markets, and vast quantities of money washed across the countryside.

And the English in the new Danish territories, having exchanged one lot of lords for another, were paradoxically discovering a new form of freedom. You didn't have to live off the estate where you happened to work; you could choose what to buy, to wear or to eat. And if you had a surplus, even a small one, you might buy yourself a little luxury: pepper or some other spice, perhaps, or even a bit of jewellery. Suddenly you had choice. And vendors were taking the opportunity to chum out cheap brooches, pots and plates to sell to these new customers.