Merlin was delighted by Arthur's words. He stepped away from me, pounding his staff on the ground in glee.

'My terms are these, Mark,' shouted Arthur up to the wall. 'As you have proven your loyalty to my crown by sending these May-children beyond your walls, I offer you a chance to prove your good faith beyond doubt. Support my champion in this trial before God, and, if I am victorious, as I surely will be, I will order my forces from Tintagel. I'll even give you your queen back, as she seems to have been put out of the gates through some error.'

'She's no queen of mine,' shouted Mark. Sir Bersulus' hand shook as he raked his thinning hair. 'The woman's a witch. I have long laboured under her enchantments. Give her to Tristan to deal with as he sees fit.'

Across from me, the knight of Cornwall gave a foul grin. 'I knew you'd realise it eventually, father. Everything I said was true.'

'That's shite king Mark of TintagHell-o,' sang Elia at the top of her voice.

Queen Melody was moved neither by Tristan's words nor those of her husband. She placed a hand on the top of Elia's head to silence her.

Sir Bersulus whispered something in his king's ear. The poor old knight was frantic. Mark pushed him away.

'Acknowledge me once more the free king of Cornwall, as you did after the War of Eleven kings, Arthur,' shouted Mark, 'and I will agree to your terms.'

Arthur feigned bafflement. 'But of course, Mark, when I have ever said different?'

'Say it, Arthur.'

The king of Camelot sighed. 'Of course I do.'

'Say it.'

Arthur winked at Sir Tristan. 'You're the free king of Cornwall, Mark,' he said quietly. 'There. Happy now?'

'I am content,' shouted Mark.

'Good, that's good,' said Arthur. 'Merlin, my old friend?'

The wizard reached inside his cloak, and from somewhere inside its folds produced two straws of hay, one longer than the other. 'Behold,' he called, showing the strands to the massed men on the left and right, and to the Cornish up on the wall. 'For the drawing of Camelot's champion.'

'And you,' said Arthur, now addressing the friends I had abandoned below the wall. 'If your champion is victorious: you all go free. If he or she loses: you die.'

Mordred held his father's black eyes, so similar to his own, and nodded.

There was a roar from the Sessite general as he showed the shorter straw to the crowd. The Sessites on my right roared their approval of the choice.

'Hermann the Sessite will champion Camelot,' announced Merlin once the cheers had died down.

Beyond Sir Tristan, Melwas was trembling. As soon as Merlin began to move towards the gates she broke, running back to the people she had left moments before. Quick as a flash of lightning, Tristan leapt towards her and tripped her up. There were roars of laughter all around us as the Gaul went sprawling in the dust.

'Now, now, my dear,' Sir Tristan said to her. 'You've already made your choice. You can't go back now.'

Mordred stepped forward before Merlin got to the group below the gates. 'There's no need for lots,' he said. 'I volunteer.'

Merlin stopped in his tracks. He sighed. 'No, no, Mordred of Erin,' said the wizard. 'That's not how it works at all. God chose Camelot's champion, so he must also choose yours.'

Piers stepped forward and stood by Mordred's side.

There was laughter from left and right. One of the British soldiers shouted: 'Best of luck, fatty.'

'Come on then,' said Piers. He spoke to Merlin, but his eyes accused Palomides.

Merlin reached inside his cloak again. He feigned surprise at what he found in his hand. 'It seems I have five straws here,' he announced. 'God desires to make his choice from all five of the remaining May-children.'

'No!' cried Sir Bersulus from the wall. 'You can't make the young ones part of this. My king, my kings, this is not just.'

Shrugging, Merlin raised the hand that contained the straws to show the old knight. 'It is as it is.' He turned to Elia, Aglinda and Alisander. 'If you please, you three most fearsome rebels.'

There was more laughter as first Elia, and then Aglinda came forward and stood beside Mordred and Piers. Alisander hung back a moment, but then his face, so often frightened, fixed into an expression of determination. He stepped away from the gates.

'Well done, 'Sander,' Aglinda said as he came to her side.

'Now, my bairns,' said Merlin. 'Choose.' He had arranged the straws in his hand so that they appeared of equal lengths, concealing which were the longer and which the shorter in his closed palm.

Mordred went first. The straw he pulled from the wizard's grip was quite short, and he was satisfied with his choice. Behind him, Iseult stood tall, now confident of her brother's success.

Piers went next. He took his straw without looking, and snarled when it showed itself to be much longer than Mordred's. 'Sorry, feller,' he said. Mordred grasped the farmer's shoulder.

Elia selected next. She chose with a relaxed swipe of her hand. Her straw was somewhere between the lengths of Mordred and Piers', while Aglinda's was almost comically long: double the length of the farmer's.

Alisander held Merlin's weird gaze as he reached up to take the last. He pulled, but it would not come free of the wizard's hand. He pulled again. 'let go!' said the Cornish boy when still he could not loosen the straw.

Merlin grinned, and opened his hand. The crowd who could see the boy erupted in gales of mocking laughter.

Hermann the Sessite shook his head. 'Dat ist no champion. Ist not honourable fight.'

The straw Alisander pinched between the nails of two fingers was little more than a stub, by far the shortest of the five.

Merlin threw his head back and joined the general amusement. 'The champion! The champion of the May-children! God has spoken!'

But Alisander was not scared as I had expected him to be. He stood quite calmly as Aglinda turned white by his side.

'My name is Alisander du Orphelin,' the boy cried out in his squeaky, unbroken voice.

'What's that?' one of the soldiers shouted. 'The little beggar said something.'

'My name is Alisander du Orphelin,' he cried again, and as the crowd shushed each other and fell silent. He said again a third time, his voice brave and still: 'My name is Alisander du Orphelin.' He looked up to the battlements where king Mark watched on. 'I am the only son of Sir Bodwyn, your own subject. You failed to protect us, Mark – I don't call you king. You allowed this man Hermann the Sessite to kill my father. You did not come to the aid of your own subjects, as aking should.' The boy shook, not with fear but with rage. He tore at his shirt to reveal the blood-stained undershirt in which his father had died, which his murdered mother had forced him always to wear. 'If the gods will it I will avenge my father today.'

Up on the wall Mark looked down blank-faced. Sir Bersulus' knuckles turned white as he gripped the stones in front of him.

'Give me a sword,' squeaked Alisander.

No one moved forward. The assembly stared at the boy in silence. Some still smirked, but others were impressed by the boy's courage when faced with such a fearsome opponent as the Sessite general.

It was Mordred who broke the silence. 'What about your sword, Arthur?' he said, strong and clear, so that everyone in the gathering could hear him.

Arthur was dumbfounded by this turn of events. His head bobbed between Mordred's black eyes and Merlin.

'Give our champion your sword to fight the Sessite, Arthur,' said Mordred.

'Ha! That is... Ha!' stuttered Arthur nervously.

The king was trapped. Not to give Alisander Excalibur to fight Hermann the Sessite would be to lose face in front of king Mark, the Cornish, and both armies at the gates of Tintagel. But the legend was that no one wielding Excalibur and wearing its scabbard could be harmed. There was a very real chance that Alisander would defeat Hermann with the sword my mother and Martha had made together. The king's mouth moved, but no words came. This was our opportunity – our opportunity, finally, to take Excalibur from Arthur's hands, as Mordred had planned almost two years before in lady Bertilak's castle. Arthur turned to Merlin, pleading with the wizard to save the situation for him.

Merlin's eyes narrowed. He stared at Mordred. 'Give Alisander du Orphelin the sword, Arthur,' rumbled Merlin, his voice unusually low and threatening.

Reluctantly, weakly, Arthur tugged at the hilt of his magical sword. He drew it six inches, and then slotted it firmly back in place. He looked at the ground, his head shaking like a child during his punishment for some mischief.

'Arthur,' said Merlin, chiding the king for his dithering.

The king of the Britons stooped over. I thought he was going to collapse, and remembered the story I had half-heard, of the time Morgan le Fay had stolen Excalibur and its scabbard, and conspired with the real Prince Accolon to turn the power of the sword against its true owner. But then the king pulled himself to his full height, and drew the glowing blade with a flourish. He inverted it, and held out the hilt for Alisander. The boy went to him and took the sword. There were a few scattered laughs as Excalibur proved too heavy for the boy's thin arms and dipped in his hands, but not many.

'Now the scabbard,' said Mordred, his voice hard as steel.

'Ha,' laughed Arthur into the hush. 'Ha ha.' Against my will I felt deep embarrassment for him; it was as if he had told a poor joke he alone found amusing. At last he uttered his weak punchline: 'You said the sword; nothing about the scabbard.'

There was a rumble of discontent from the British soldiers; even they appreciated that their king had been trapped by Mordred's request, and was attempting an infantile, dishonourable escape.

'The sword, the sword, the sword, the sword,' chanted the king, shuffling from one foot to another in an uncoordinated dance. 'Not the scabbard.' He turned to Merlin for approval. The wizard did not look at him, though the empty eyes of the ram's skull rotated to observe the wheedling man. Caught in that dead gaze, Arthur calmed himself and was still.

'The king has given up his sword as you requested, Mordred of Erin,' said the wizard. 'It is time.'