My heart seized in my chest. I stared at the creature, not daring to draw breath. The thing was squat and repulsive, with two long arms and a large-skulled, flat head. Its short legs were drawn up as it sat on its rump, its back curved sharply as its dark head descended towards Peredur's face.

At first I feared the thing must have killed him, for the young warrior lay with arms and legs splayed out as he had fallen. But as that ghastly head drew near, Peredur moaned. By that I knew he lived.

Instantly, my hand went to the sword belt at my side. As my fingers closed and began to draw the weapon forth, the creature halted and, quick as a cat, turned its gaze on me. A more grotesque face I never want to see: low-browed and thin-jawed, with a nose like a shrivelled leaf, nostrils a-twitch as it sniffed the air; a goatlike mouth with long yellow teeth gaped open in a hiss of warning. Two wide, pale eyes menaced me from beneath the heavy brow as the head sank lower onto the shoulders and the long hands clutched at its prize.

Great King, save your servant! I thought, and the thought was answered by a low guttural growl bubbling up from the hideous creature's throat. I fell back.

With a scream, the creature leapt from Peredur's chest, charging straight at me with terrible swiftness. I stumbled back another step, tripped over broken wood, and fell down. The thing was upon me in an instant. The beast's awful breath smelled of rotted meat and foul decay. I felt its sudden weight upon my chest, driving the breath from my lungs. I made to throw the creature off, but could no longer raise my arms. It was as if all the strength had gone from my limbs, and I could but lie and watch in horror as the odious thing lowered its face towards mine.

Alas, for me! I could not move. I could not breathe.

The repugnant head dropped slowly nearer, and the toothy mouth opened. Striving with all my might, I could not so much as lift my smallest finger. I felt myself gripped tight by a strength greater than my own.

Closer, drooling now, the evil mouth drew nearer, and nearer yet. I saw the small, neat, sharp teeth as the mouth opened and the creature prepared to bite.

My lungs burned. Frozen fast, I could but watch the dread face slowly descend, its baleful eyes blotting out all else, filling my sight, staring into my soul.

Even as I watched – I could do no else! – the face utterly changed and I found myself beholding the face of a woman, a beauty more lovely than any other I had ever known. Lithe-limbed and supple, she reached to gather me in her gentle arms, her long dark hair falling down around her white shoulders. Her breasts were full and round, and wonderful to look upon; her shapely hips were smooth and her long legs folded beneath her. She smiled, and her teeth were fine and white and straight. A goddess could not be more beautiful, I think, and despite my fear, desire stirred within me.

She lowered herself to cover me with her fair body, and I felt myself drawn into her embrace. My lungs swelled to bursting, yet I could not draw breath. The blood beat in my temples and dark mist gathered before my eyes. God help me, I rose to meet her.

Then, even as I felt the sweet gentleness of her soft lips on mine, and felt my breath drawn from my mouth, there came a shriek so loud, so piercing, I feared my head would split. In the same instant, the woman vanished, and the beast appeared once more, its mouth open in a scream of rage.

I sensed a swift movement above me and a dark shape descending. The loathsome thing made to leap away, but the falling shape caught the creature full on its flattened skull with a tremendous crack. The monster threw back its head and howled. Crack! The dark shape sent it sprawling.

Suddenly I could breathe again. Good air came rushing into my mouth and lungs, and I gulped it down like a drowning man who has risen from the killing depths.

Peredur was standing over me, the broken end of a massive branch in his hands. His jaw was set and his eyes were narrowed. Still gasping, I turned my gaze to where he was looking, and saw the black beast writhing on the ground, biting itself in agony.

'Blessed Jesu,' I gasped, 'save us.'

At these simple words, the vile thing loosed a shriek yet more terrible than any I had ever heard. There came a sizzling sound and it vanished into a sudden vapour, leaving behind only the echo of its tortured scream, and a stench of bile and vomit.

Peredur turned to me. He tried to speak, but lacked words to equal the event, and so closed his mouth and gazed in wonder at the place where the beast had disappeared. Then he raised the club in his hand and looked at it as if he did not know how it had come to be there. He threw the weapon aside with an expression of disgust. 'I feared it might have killed you,' he said, almost apologetically.

'You did the right thing,' I assured him.

Peredur shivered and glanced down. Only then did he realize that he was naked. He glanced guiltily at me, but I turned away so he would have no need to make the explanation he was struggling to find. I knew well what had been in his mind when he shed both siarc and breecs.

'Your clothes are here,' I told him, gathering up the bundle where I had dropped it. He accepted the clothing with shamefaced gratitude. 'I did not see what happened to your boots.'

'I -1 mean, it was -' he stammered.

'Save your breath, lad,' I advised gently. 'You owe me neither explanation nor confession. We were attacked, and fought it off. There is nothing else to say.'

Peredur closed his mouth and began drawing on his breecs. We then picked our way back to the ruined hall. Our camp, I was relieved to find, remained undisturbed; both Llenlleawg and Tallaght slept soundly.

'Lord, let us leave at once,' said Peredur. 'Let us get far away from here before we are attacked again.'

Though it was the dead of night, and darker than the inside of a burial mound, I agreed. 'We may not get far in this darkness,' I told him, 'but at least we will get away from here.'

We quickly saddled the horses and prepared to depart, then turned to wake the sleepers. Despite our vigorous attempts to raise them, however, the two slept on. Nothing we did made the slightest difference. 'Let us put them on the horses anyway,' suggested Peredur in desperation.

'We would have to tie them to the saddle,' I replied, 'to keep them from sliding off at every step. No, Peredur, as much as I wish to be gone from here, we could easily come to greater harm stumbling around like blind men in the dark. If we are going to be hauling men like mealbags on horseback, I think we must wait until daylight.' Indicating his feet, I said, 'You cannot walk back to Ynys Avallach barefoot.'

With great misgiving and greater dread, Peredur set about building up the fire and together we stood watch for the rest of the night, weapons in hand, our backs to the flames as we searched the darkness, talking to one another to keep fear at bay.

Dawn seemed a long time coming. When the sun finally rose, it cast but a wan grey light over us – as on those days in the north when the mist comes down and lingers on the heathered hills, but there was no cooling mist, and the hills hereabouts held only dry scrub and thorns.

As soon as it grew light enough to see the path, we broke camp. Peredur retraced his steps to the blighted wood, returning quickly with his boots, anxious to get away from the ruined caer as soon as possible. We turned to the sleepers and tried again to wake them. Tallaght had finally lost the unnatural rigidity of his limbs, and now lay peacefully asleep. I bent to remove the strip of cloth from his eyes and the young man came awake at my first touch. Up he charged, as if from a bed of live coals. He flew into me, fists flying, kicking, biting, shouting incoherently.