The slave smiled at the priest. 'The children of God.'

Arngrim said, 'Ibn Zuhr tells me that his people believe their civilisation to be the most advanced in Europe. All that ancient learning they preserved, you see.'

The priest sneered. 'Such claims are easy to make.'

'But my medicine has soothed your king,' Ibn Zuhr pointed out.

'Where are you from? Africa?'

'No. Al-Andalus. Which is in Iberia.'

'Tell me how you come to be here.'

'Because of the Northmen…'

When the western Roman empire had collapsed, German immigrants called Visigoths took over the former province of Iberia. They maintained the old Roman machinery of government, and in time the province had become a strong, unified, Gothic Christian nation. But Africa was only a short sea journey away to the south. And there, new forces stirred.

A mere seven decades after the death of the Prophet the armies of Islam swept across North Africa, and launched a series of devastating assaults into Iberia. In just four years the horde had burned across the peninsula, shattering the fragile Gothic state, and had even pushed into southern Frankia. Their advance resounded across a nervous Europe, and was noted by Bede in faraway Northumbria.

In Iberia the Muslims built a new nation, eventually independent of the caliphate in Damascus; it was called al-Andalus, an Islamic society within western Europe. Soon al-Andalus was exchanging embassies with Constantinople.

Then the Northmen came. Raiding across Europe, they sent their dragon ships sailing up the great rivers of Iberia to assault the cities of al-Andalus, just as they had raided elsewhere. The emirs, stronger and better organised than the post-Roman monarchies of Europe, turned them away.

But still the Vikings pressed. Sixteen years ago, Ibn Zuhr said, two adventurers called Bjorn Ironsides and Hasting had led a bold raid down the western coast and into the Mediterranean sea. Their ultimate goal had been to reach the treasures of Rome. In this they failed, but they did make it home with a cargo of treasure and captives from al-Andalus – one of them Ibn Zuhr, then a young man of twenty from a city called Granada. He had been sold into slavery in Ireland, and then, when his pharmacological skills had been proven, sold on at higher prices through a chain of owners until he finished up in a market in Brycgstow, where Arngrim had spotted him.

Cynewulf shook his head. 'From Lindisfarena to Iberia, the Northmen do mix up our lives.'

There was a sound like distant thunder, dimly discernible beyond the walls of the noisy hall. Arngrim turned to the door, frowning.

Cynewulf asked, 'And do you worship God, Moor?'

'Muhammad was the prophet of the one God,' Ibn Zuhr intoned.

'And what of Jesus?'

Arngrim said, grinning, 'To them He is just another prophet.'

'This man is a pagan then,' snapped Cynewulf.

'But he isn't,' said Arngrim. 'I'm no more a theologian than I am a scholar. But it seems to me that the faith of this chap is based on a prophet who came after the Christ. Now, how can you priests make sense of that?'

Cynewulf shook his head. 'This is a testing age for Christianity. The Pope says so. We are caught between the pagans of the north and these unbelievers from the south. Do you seek to crush us, Moor?'

'That is for the emirs,' Ibn Zuhr said gently, 'not for me.'

Aebbe asked, 'What about prophecies? Can your God see into the past and future, even change it?'

'Allah is unknown and unknowable.'

Which was no answer, Cynewulf thought, and yet a very deep one. Fascinated, irritated, longing somehow to puncture the sleek hide of this very certain man, he tried to frame his next question.

And then the door was smashed down. Freezing air flooded in. The wall lamps flickered.

The invaders ran straight into the hall, roaring.

Tall, helmeted men, they wore coats of leather, and they swung gleaming axes. They ran down the central aisle, between the great oak pillars. They even climbed on to the long tables, running. None had shields. Perhaps they believed no shield would be necessary.

And those cruel axes swung, lopping off heads and limbs with single strokes, and swords stabbed into crowded flesh. Suddenly there was blood everywhere, an iron stink, and a fouler smell of loosened bowels. The hall became a churn of flesh. And the English warrior nobility ran screaming, as panicked as sheep.

For Cynewulf, still sitting stunned on his bench, it was a transition from light to dark, from order to chaos, from humanity to something bloody and primeval, and it had happened in a heartbeat, less. And he was shocked by the youth of these rampaging men. Few of them looked much over twenty. There was an avidity about their work, a joy in killing.

Arngrim dragged Cynewulf to his feet and pulled him back against the wall, out of the crush. He was armed with a boar spear he had taken from the walls, and his expression was an iron mask. 'We have to move.'

'Arngrim, how can this have happened? There was a truce.'

'Broken. It doesn't matter. Are you listening to me? Ibn Zuhr, get him out of here.'

The Moor, calm as ever, took the priest's arm.

But in that moment Cynewulf saw Aebbe fall under the crush of the mob. He pulled at the Moor, but Ibn Zuhr's grip was strong, and he couldn't reach her.

One older man, a bovine brute in a coat of thick chain-mail, stood on a table and pointed to Alfred's throne. He spoke Danish, a tongue too many English had been forced to learn, and Cynewulf heard clearly what he called. 'There he is! The King! Follow me, Egil son of Egil! Follow me!' He went thundering down the tabletop, a mob behind him, scattering plates and cups as he went. He was like a bull, Cynewulf thought, horrified, a huge and heavy animal, not something human at all. And he was heading for the King.

Arngrim leapt up to face him. Without armour or helmet, armed with only the boar-spear, the thegn stood his ground on the tabletop. The assault was reduced to this fundamental essence, two men, one roaring forward, the other standing calm and resolute as a rock.

With his last pace Egil swung his bloody axe.

Arngrim ducked and slashed with his spear, aiming for the Dane's hip beneath his mail shirt.

Egil's axe deflected the spear's tip but its shaft slammed against his rib. Egil lost his balance and fell with a crash off the table into the churning crowd. In an instant he was on his feet, laying about him again, hacking through people as if through a bank of seaweed.

For an instant his eyes met Arngrim's. Cynewulf had been around warriors enough to understand the bleak promise in that gaze, a pact that could only be resolved in death.

But Cynewulf reached up and grabbed Arngrim's arm. 'Never mind him. The King! Save the King!'

Arngrim jumped to the floor and snatched a sword from a pile of armour on a bench. 'Get him out of here, Moor.'

'But Aebbe-'

'She is lost. For now, the King.' He yelled, 'Englishmen, with me!' And, sword raised, he ran down the hall towards the throne.

Alfred was struggling amid a mass of panicking warriors and priests, through which Northmen were hacking to get to him. Arngrim, huge amid the chaos, screamed for discipline. Gradually a bank of fighting men built up before the King.

And there was a stink of smoke. Cynewulf realised that the Danes had torched the building. As Ibn Zuhr dragged him away, Cynewulf was overwhelmed by the stench of blood and fear and death, dizzy at this sudden catastrophe – and bewildered by the loss of Aebbe.

V

His gut pressed to the cold earth, his face smeared with dank river-bottom mud, Arngrim crawled like a snake along the eroded ridge. He felt very exposed. This January morning, nature offered little cover, the trees bare, the undergrowth withered. He even tried to breathe shallowly, to avoid the steam of his lungs rising up and betraying him.