‘A timber hall,’ he said dreamily, ‘with a pillared arcade facing the sea. Guinevere loves the sea. The land slopes southwards, towards a beach, and we can make our hall above it so that all day and night we can hear the waves falling on the sand. And behind the hall,’ he went on, ‘I shall build a new smithy.’

‘So you can torture more metal?’ I asked.

‘Ars longaj he said lightly, ‘vita brevis.’

‘Latin?’ I asked.

He nodded. ‘The arts are long, life is short. I shall improve, Derfel. My fault is impatience. I see the form of the metal I want, and hurry it, but iron won’t be hurried.’ He put a hand on my bandaged arm. ‘You and I have years yet, Derfel.’

‘I hope so, Lord.’

‘Years and years,’ he said, ‘years to grow old and listen to songs and tell stories.’

‘And dream of Britain?’ I asked.

‘We served her well,’ he said, ‘and now she must serve herself.’

‘And if the Sais come back,’ I asked, ‘and men call for you again, will you return?’

He smiled. ‘I might return to give Gwydre his throne, but otherwise I shall hang Excalibur on the highest rafter of my hall’s high roof, Derfel, and let the cobwebs shroud her. I shall watch the sea and plant my crops and see my grandchildren grow. You and I are done, my friend. We’ve discharged our oaths.’

‘All but one,’ I said.

He looked at me sharply. ‘You mean my oath to help Ban?’

I had forgotten that oath, the one, the only one, that Arthur had failed to keep, and his failure had ridden him hard ever since. Ban’s kingdom of Benoic had gone down to the Franks, and though Arthur had sent men, he had not gone to Benoic himself. But that was long in the past, and I for one had never blamed Arthur for the failure. He had wanted to help, but Aelle’s Saxons had been pressing hard at the time and he could not have fought two wars at once. ‘No, Lord,’ I said, ‘I was thinking of my oath to Sansum.’

‘The mouse lord will forget you,’ Arthur said dismissively.

‘He forgets nothing, Lord.’

‘Then we shall have to change his mind,’ Arthur said, ‘for I do not think I can grow old without you.’

‘Nor I without you, Lord.’

‘So we shall hide ourselves away, you and I, and men will ask, where is Arthur? And where is Derfel? And where is Galahad? Or Ceinwyn? And no one will know, for we shall be hidden under the birch trees beside the sea.’ He laughed, but he could see that dream so close now and the hope of it drove him on through the last miles of our long journey.