The day passed in a haze of blood and havoc. As the sun descended westward, I heard Rhys raise the retreat and knew that we were beaten. I gathered my division and we withdrew with our wounded; everywhere warriors were streaming down the hillside to the refuge of the wood.

The enemy seemed eager to give chase at first – would that they had done so! We would have cut them down with the a/a. But Cerdic knew enough to halt the pursuit at the lower ditch, and the barbarians returned to the hill fort.

While the warriors lay under the trees recovering strength and having their wounds bound, the cooks and stewards brought us meat and bread and watered ale, and we ate. My limbs ached and my head throbbed. My clothing was sodden with sweat and blood. I stank.

A still and sinister dusk settled over the land. The trees around us filled with crows from the battlefield, croaking grotesquely over their ghastly feast. But that was as nothing to the wild cries of victory from the hill fort above us. Fires leapt high into the darkening sky as the victory celebration commenced.

We slept fitfully that night, the sound of savage revelry loud in our ears. At dawn we awoke, broke fast, took up our weapons and climbed the hill once more. The barbarians allowed us to crawl so far and then fell upon us, hurtling down from the heights, axes whirling.

We took them on the points of our spears and swords, and struck them with our shields. But many a warrior fell, his helm or shield or mail shirt riven asunder. The carnage was appalling, the tumult deafening.

Once again the flanks of Baedun Hill blushed crimson with the blood of the brave.

And once again, as the sun passed midday Rhys signalled the retreat and we withdrew to the wood to Uck our wounds. The warriors sank to the grass and slept. The stewards crept among them with water jars and woke the sleeping soldiers to drink. The wood grew still, given only to the hum of flies and the flutter of birds' wings in the branches above. On Baedun, the enemy was silent.

When they had refreshed themselves and put off their weapons the lords of Britain held council with Arthur.

'I say we must lay siege to the hill and send south for more men.' This was Maglos' suggestion, and after the heavy going of the morning, several agreed with him.

'If we could only take the fortress,' began Ceredig, but he was cut off by the scorn of the others.

'Take the fortress!' Idris shouted. 'What else were we doing up there? It is impossible – there are too many! I agree with Maglos: we should lay siege and wait for more men.'

'No,' said Arthur. 'That we cannot do.'

'Why not?' demanded Idris. 'It worked at Caer Alclyd; it worked at Trath Gwryd… '

'It will not work here,' Arthur told him flatly.

But Idris gave no heed to the iron in Arthur's voice. He persisted, saying, 'Why? Because you want to exalt yourself over Cerdic?'

'If that is what you think – ' I snapped, jerking my head toward the hill, 'join him!'

Myrddin, leaning on his rowan staff nearby, stirred and came near. 'This hill is cursed,' he intoned softly. We all quieted to hear him better. 'There is distress and calamity here. The slopes are treacherous with torment, and disaster reigns over all.'

We all glanced over our shoulders at the looming hill. The clouds playing across its surface gave it a brooding, dangerous aspect. Certainly, the corpses scattered on its rock-crusted slopes argued eloquently for disaster. Myrddin did not need sight to know our torment – but what else did he see?

'In older times armies have fought upon this troubled mound. A great victory was won here through betrayal, and the wicked defeat of good men clings to the earth and rocks. The mountain is unquiet with the evil practised upon it. Cerdic's treachery has awakened the vile spirit of this place to work again.'

Tell us, Emrys,' said Custennin. 'Give us benefit of your wise counsel. What are we to do?'

It was the formal request of a king to his bard. Myrddin did not fail to oblige. 'This battle will not be won by stealth or might. It will not be won by bloodshed alone. The spirit abiding here will not be overthrown except by the power of God.'

The lords peered helplessly at one another. 'What are we to do about that?' they demanded.

'We must pray, lords of Britain. We must erect a fortress of our own whose walls cannot be battered down or broken. A caer that cannot be conquered. A stronghold of prayer.'

Some of the lords scowled at this, embarrassed at their lack of faith and understanding. But Arthur rose and said, 'It will be done as you say, Wise Counsellor."

Myrddin placed his hands on Arthur's shoulders. 'I will do all to uphold you – as I have ever done to this day.'

Though men may scoff, it is no small thing to be upheld by the Chief Bard and Emrys of Britain.

The next morning, as we arrayed ourselves for battle, I saw the solitary figure of Myrddin toiling up the hillside, picking his slow, blind way with his staff, his cloak wrapped tightly around him. For the day broke grey and misty, and a chill wind blew at us out of the north.

'Do you want me to go after him?' I asked, fearful for Myrddin's safety.

'Wait here. I will go to him,' replied Arthur, starting after the stumbling Emrys.

I watched Arthur stride out upon the hillside. Cai and Bors saw him and came running to where I stood at the edge of the wood. 'What is he doing?' asked Bors. 'Does he think himself invisible?'

'I do not know,' I answered.

'I am going to bring him back,' said Cai.

'He said to wail here. But signal Rhys to be ready to sound the attack. If the barbarians come over the wall, I want the Cymbrogi to move at once.'

Llenlleawg, who had been lurking nearby, came to stand beside me. He spoke not a word and his eyes never left the hill, but he gave me to know that our hearts beat as one for Arthur.

'Now what are they doing?' wondered Bors aloud. 'It looks as if they are gathering stones.'

God's truth, that is what they were doing. Arthur, after a brief word with Myrddin, stooped and began piling rocks upon the ground. Myrddin laid aside his staff and, kneeling down, began to heft rocks onto the pile.

They are building a cairn,' observed Cai, eyes wide with disbelief.

'Not a cairn,' I said. 'A wall.'

'Bah!' huffed Bors, who was having none of it. 'They will get themselves killed out there as soon as the enemy stirs.'

The leaden sky had lightened somewhat with the rising sun. Arthur and Myrddin toiled openly on the slope. The enemy must have observed their presence by now. Our own army had gathered at the edge of the wood to view the strange proceedings.

'We cannot let this continue,' blustered Bors. 'It is not meet for the Duke of Britain to heap rocks on the ground.'

'What do you propose?' I asked.

'You must stop him!'

'You stop him.'

Bors drew himself up. 'Very well, I will.' So saying, he stalked from the wood.

Gwalchavad came running to us. 'What is happening? What are they doing out there?"

'Building a wall," Cai replied.

Gwalchavad opened his mouth to laugh, and then stared in amazement. They are!' he declared. They will be killed!'

'Possibly,' I allowed.

'Is no one going to stop them?'

'Bors is going to do that,' said Cai.

Gwalchavad gaped at us as if we had lost our reason. Out on the hill Bors picked his way among the tumbled stones. 'Well, he will need help,' Gwalchavad said, and hastened after Bors, who had reached the place where Arthur and Myrddin toiled.

The lord of Benowyc waved towards the hilltop stronghold and then in the direction of the wood. Arthur raised his head, spoke a word, and Bors stopped gesturing. The Duke returned to his labour and Bors stood looking on.

'Look at that,' scoffed Cai. 'Bors has certainly stopped them."