‘Who are they?’ Arthur demanded, staring back at the horde.

‘Nimue’s army,’ I said bitterly. Thanks to Morgan’s skill, Nimue’s charms had failed and so she had unleashed her followers to fetch Excalibur and Gwydre.

‘Why didn’t we see them coming?’ Arthur wanted to know.

‘A charm of concealment, Lord?’ Taliesin guessed, and I remembered how often Nimue had worked such charms.

Galahad scoffed at the pagan explanation. ‘They marched through the night,’ he suggested, ‘and hid in the woods until they were ready, and we were all too busy to look for them.’

‘The bitch can fight Mordred now instead of us,’ Culhwch suggested.

‘She won’t,’ I said, ‘she’ll join him.’

But Nimue had not finished with us yet. A group of horsemen were galloping on the road that led northwards about the swamp, and a horde of folk followed those spearmen on foot. The river did not run straight to the sea, but made vast loops through the coastal plain and I knew that at every western curve we would find’ the enemy waiting.

The horsemen did indeed wait for us, but the river widened as it neared the sea and the water ran swiftly, and at each bend we were swept safely past them. The horsemen called curses down on us, then galloped on to find the next bend from where they could launch their spears and arrows at us. Just before the sea there was a long straight stretch of the river and Nimue’s horsemen kept pace with us all down the length of that reach, and that was when I first saw Nimue herself. She rode a white horse, was dressed in a white robe, and had her hair tonsured like a Druid. She carried Merlin’s staff and wore a sword at her side. She shouted at us, but the wind snatched her words away, and then the river curved eastwards and we slid away from her between the reed-thick banks. Nimue turned away and spurred her horse towards the river’s mouth.

‘We’re safe now,’ Arthur said. We could smell the sea, gulls called above us, ahead was the endless sound of waves breaking on a shore, and Balig and the Saxon were hitching the sail’s yard to the ropes that hoisted it up the mast. There was one last great loop of the river to negotiate, one last encounter with Nimue’s horsemen to endure, and then we would be swept out into the Severn Sea.

‘How many men did we lose?’ Arthur wanted to know, and we shouted questions and answers back and forth between the small fleet. Only two men had been struck by arrows, and the one stranded boat had been overwhelmed, but most of his small army was safe. ‘Poor Emrys,’ Arthur said, and then was silent for a while, but he pushed the melancholy aside. ‘In three days,’ he said, ‘we’ll be with Sagramor.’ He had sent messages eastwards and, now that Mordred’s army had left Dumnonia, there was surely nothing to stop Sagramor coming to meet us. ‘We shall have a small army,’ Arthur said, ‘but a good one. Good enough to beat Mordred, and then we start all over again.’