They spoke together like this for a time, and then the king drew himself up, turned, squared his shoulders, and said, 'Very great evil has been practised here, and we, who strive towards the light, bear witness to this vile deed and condemn it before the throne of God. Yet, though life has abandoned our brothers, we will not forsake them in ignoble defeat.

'Here in the camp of the Evil One we will kindle a light, and send this light like a spear into the very heart of the darkness that oppresses us. As light shining in the midst of darkness overcomes that darkness and banishes it utterly, so we shall drive it from the hand of the enemy who would employ it as a weapon against us. And the dread tree on which hang the bodies of our friends will become a funeral pyre, and the flames that light our brothers' homeward way will become a beacon of our defiance.'

When Arthur finished speaking, I added my own voice to the acclaim that welcomed the king's pronouncement. Oh, we made that blighted wood ring with righteous adulation. And then we hastened to the edge of the wood round about to gather a bounty of dead wood for fuel, and when we had heaped the tinder man-high around the ancient oak, Myrddin caused the remnant of the Dragon Flight to make a wide circle around the tree.

He then commanded us to walk slowly in a sunwise direction. Led by Arthur, we began; meanwhile, the Emrys stepped to the tinder heap and raised his staff high. Calling in a loud voice, he cried out, 'Great Light, whose life is light and power to his creatures, hear your servant!'

Taking the staff with both hands now, he held the oaken rod above his head and cried, 'We who journey in darkness have need of your light. We who are bereft of hope and beset by evil on every side have need of your power. Lord, in our day of travail, hear our cry!

'Great Light, our kinsmen have been wickedly murdered, and their bodies given over to death.' His voice resounded across the meadow. 'You alone, Lord, hold authority over the grave. Even as your voice quickens the spirit in the womb, so you summon the spirits of the departed to your throne. Therefore, we ask you to call our brothers home to your Otherworldly realm, and give them places of honour in your banquet hall.

This night great evil gathers close, seeking to destroy us. Yet we will trust in you, Lord, to deliver us. If this cannot be, then we trust you to meet us on the way and guide us to your halls. In token of our trust, we light this pyre to hold the darkness at bay. Let it burn as a beacon to light the homegoing of our swordbrothers and put evil to flight.'

Holding the oaken rod above his head, he stood for a long moment and then slowly lowered the staff and extended it towards the firewood. There was a flash of blue and a sound like the tearing of a cloak between giant hands. The fire simply appeared, arcing through the air, flowing like shimmering liquid, leaping from branch to branch, and scattering in bright blue tracery through the dry wood. Within moments the flames were cracking hot and bright, licking up through the tinder heap, leaping up and up into the great spreading branches.

Turning to the Cymbrogi, Myrddin said, 'Sing! Make a noise to rouse the Heavenly Host!' With that he led us in a psalm such as the brown clerics chant in the Holy Mass:

The Lord is my rock!

The Lord is my fortress, and my deliverer!

God is my refuge; He is my shield!

And the horn of my salvation, my stronghold.

The flames mounted higher, stretching into the branches, caressing the lowermost corpses. Ringed by fire, the massive black trunk began to smoulder as the yellow flames stretched higher and ever higher into the tree.

Still walking, maintaining the circle, we began to sing with the Emrys, chanting the words as he led us.

I call to the Lord who is worthy to be praised,

And I am saved from my enemies.

The cords of death entangled me;

The torrents of destruction overwhelmed me

The cords of the grave coiled around me; The snares of death confronted me. In my distress, I cried to my God for help. From his temple he heard my voice.

The heat from the flames forced us back, making our circle larger still. The corpses, now alight, began swinging and twisting in the quickening wind created by the flames. The boughs creaked and cracked as the flames tripped from branch to branch, higher and still higher into the sky.

The earth trembled and quaked,

And the foundations of the mountains shook;

They trembled because he was angry.

There came a long, sighing crack. All at once the mighty tree slumped inwardly upon itself. Riven by fire, the trunk of the oak split, sending sparks spiralling upward on the rising air like thousands of tumbling stars. It seemed to me that these were the spirits of our friends taking flight towards Heaven.

And he looked down in his anger and said: Because their love is set on me, I will deliver them. I will deliver them from danger, for they know my name. I will be with them in times of trouble; I will rescue them from the grave, And bring them honour in my courts; I will satisfy them with eternal life to enjoy their rich salvation.

I said the words as Myrddin spoke them, and watched the glimmering sparks rising up and up, and I thought, Farewell, Cai, stalwart companion, faithful through all things. Farewell, Bedwyr, loyal brother, steadfast in the fight. Farewell, Cador, brave and true. Farewell, my friends, enter into the Peace of Christ. Farewell…

My heart rose to my throat and my eyes filled with tears, and the burning oak blurred into a blazing mass of shimmering, shifting light, and I heard a roar like thunder as the gathering wind rushed to feed the towering flames, whipping them to white heat. The light that blazed from the pyre filled the wide meadow now, forcing back the darkness on every side.

I heard the wail of the wind, and the cold air gusted, swirling around us. My back was cold, my face and hands searing hot from the blaze before me. The scream grew louder and I realized it was not the cry of the wind, but the wild scream of a creature tortured beyond endurance. What is more, the creature was coming swiftly towards us, drawn by the fire.

Myrddin heard the sound, too, and cried out, 'Fear nothing! Greater is he who has heard our prayer than that which assaults heaven with its cry.'

As it rose above the wind, shivering the wood all around us, I felt the wild, keening sound in my belly and then in the quiver of the earth beneath my feet. I thought at first that it must be the Shadow Beast returning to attack us again, but the trembling mounted steadily and I knew it must be something far, far larger and more deadly.

'Listen to me!' cried Myrddin, and he began instructing us on how to survive the onslaught we would soon face. We were to link arms, he said, and form an outward-facing ring, an enclosed wall with our bodies. Where men might be too far apart they should hold a spear between them, but under no condition were we to break the chain. 'Though Hell itself break over you, do not let go,' the Emrys said. 'Whatever you may see, whatever you may hear, do not break the circle. Keep the ringwall intact and, though the Devil himself leads the attack, we will not be harmed.'

I reached out to the man next to me – it was Rhys, his face grim in the lurid light. We linked arms, then clasped hands with the warriors on either side and braced ourselves for the assault. The ground began to shake, and I heard a sound like that of giants crashing through the wood, uprooting trees, and casting them aside. The very earth trembled beneath our feet, and the forest all around cracked and groaned with the snapping of branches and the twisting of limbs. What, I wondered, could cause such destruction?