The being pointed to the stone slab which rested at the vortex of the hill's power. I turned to see the stone – blue now, like the rest of them, and shining faintly. I stepped up onto the stone and heard the druids gasp behind me, for only the Chief Druid may touch the stone – and never with his feet!

But I stood on the stone and it rose up. So highly charged had the vortex become that it lifted the stone, with me on it, straight into the air. From this lofty vantage I began to speak, rather the Ancient One spoke through me if that is how it was, for the words were not my own.

'Servants of the Truth, stop your whining and listen to me! Indeed you are fortunate among men, for today you witness the fulfilment many have lived and died longing to see.

'Why do you wonder that the wisest among you should greet you in the name of Jesu, who called himself the Way and the Truth? How is it that you, who seek truth in all ways, should be blind to it now?

'Do you believe because you see a floating stone?' I saw that they did not believe, though many were awed and amazed. 'Perhaps you will believe if all the stones dance?'

At that moment I actually believed that I could do such a thing, that I had only to clap my hands or shout, or make some sign and the stones would shake themselves from the ground to swing in whirling dance through the glistening air.

I believed, and so I clapped my hands and gave a loud shout – it did not sound like my own voice at all, for the shout resounded over the land, echoing in the glens and valleys round about, trembling the stones of the magic ring in the earth.

Then, one after another, the standing stones began to rise.

One by one they pulled themselves from their sockets, like teeth twisting themselves from the jaw that holds them, and they rose trailing dirt to stand in the air. And then, when all were together in the air, those ancient stones began to turn.

Around and around, slowly, slowly at first, but then a little faster, each stone began turning around its own axis as it whirled in the air.

The druids looked on in horror and wonder, some cried out in fright. I thought to myself that it was a handsome sight – those heavy blue stones spinning and whirling in the shining air, as in a dream.

Perhaps it was a dream after all. If so, it was a dream we all shared together with eyes wide and staring, mouths open in disbelief.

Once, twice, and again, the stones whirled through their course. From my place on the Druid Seat, I heard my own voice ringing, high and strange, voicing a song, or laughter – I know not which – to the stones dancing in the air.

I clapped my hands again and the great stones plummeted instantly to earth. The ground shook beneath them and the dust rose in a cloud. When it cleared, we saw that some of the stones had fallen back into their socket holes; most, however, simply lay where they dropped. One or another had cracked and shattered and the ring was broken.

The stone on which I stood had settled back onto its place, and I stepped off. Blaise, his face alight with the wonder of what he had seen, rushed towards me and would have taken hold of me, but Hafgan restrained him, saying, 'Do not touch him until the awen has passed.'

Blaise made to step back, caught sight of the Druid Seat and thrust his ringer towards it. 'For any inclined to doubt what we have witnessed this day, let this be a sign of the truth of what we have seen.'

I looked at where he was pointing and saw the prints of my feet etched deep into the stone of the Druid Seat.

So the Great Light was proclaimed among the Learned Brotherhood that day. Some believed. Others did not. And although none could deny the power of what they had seen, some chose to attribute the miracle to a different source.

'It is Lieu-sun!' some said. 'Mathonwy!' said others. 'Who else has such power?'

In the end, Hafgan lost his temper. 'You call me Wise Leader,' he said bitterly, 'but refuse to follow where I lead. Very well, from this day let each man follow who he will. I will not remain Chief of such small-minded and ignorant men!'

With that, he raised his staff in both hands and broke it over his knee, then turned his back and strode from the assembly. The Learned Brotherhood was dissolved.

We followed Hafgan from the grove – Blaise, Charis, myself, and two or three others – and returned to the glen where the warband was waiting. We broke camp at once and rode south towards Yr Widdfa. Hafgan wanted to see the great mountain again, and to show us where he was born.

He was angry for a time after leaving Garth Greggyn, but this passed very quickly and he soon appeared joyful and more content than I had ever seen him – singing, laughing, talking long and happily with my mother as we rode along – a man freed from a tiresome burden, or healed of a wearying pain. Blaise noticed the change as well, and explained it to me. 'He has been divided in his heart for a very long time. I think he wanted to force the decision back there, and now that it is over he is free to go his own way.' 'Divided?'

'Between Jesu and the old gods,' Blaise replied. 'As Chief Druid he must uphold the eminence of the ancient gods of our people, though that has become distasteful to him hi the years since he discovered the Great Light.' I must have frowned or shown, my lack of comprehension, for Blaise added, 'You must understand, Myrddin Bach, not every man will follow the Light. Nothing you or anyone else can do will change that.' He shook his head. 'Though dead men rise from their graves and stones dance in the ak, they will still refuse. It makes no sense, but that is the way of it.'

I did not altogether believe him. I thought he was telling me the truth as he saw it, and respected his insight; but in my innermost heart I thought that if men did not believe the truth it was only because a better way of explaining had yet to be discovered. There is a way to make all men see, I thought to myself, and I will find it.

Two days later we sat on a high hill, the wind riffling the sparse grass and sighing among the bare rocks as we gazed at the cold, white-topped and solitary splendour of Yr Widdfa, Snow Lord, Winter's Fortress.

In that lonely land of brooding peaks and darksome vales it is easy to believe the things whispered before the firelight, the tales and scraps of tales men have passed to their children for a hundred generations and more: one-eyed giants in halls of stone; goddesses who transform themselves into owls to haunt the night on soft, silent wings; water maids who lure the unwary to rapturous death below the waves; enchanted hills where captured heroes sleep the centuries away; invisible islands where gods cavort in the twilight of never-ending summer…

Easy to believe the unbelievable there among the hollow hills.

We dismounted and ate a meal on the hilltop, then rested. I did not care to sleep, and decided to walk down to the valley and fill the water jars and skins at the stream. It was not a difficult walk, nor even very far, thus I did not pay particularly close attention to the features of the land – not that this would have helped.

I stumbled and slid down the hill, laden with skins and jars swinging from their thongs round my neck and shoulders. A quick-running stream lay in the centre of the valley, in among the tight tangles of blackthorn and elder. I found a way in to the water and set to filling the skins.

I cannot say how long I was at it, but it could not have been long. Nevertheless, when I gathered up the filled containers and stood to look around, I could no longer see the hill: a dense, grey fog had come down from Yr Widdfa and wrapped the higher hills in a clotted mass thick as wool.

I was concerned, but not frightened. After all, the hill stood directly before me. All I need do was put one foot in front of the other and retrace my steps to the top where the others waited. I wasted no time, but set off at once in the event that the others awoke and became anxious to find me missing and a fog filling the valley.