‘Perhaps she will,’ Merlin said sadly, ‘and I would like that, Derfel. I would like to have my eyes back, and my youth, and my joy.’ He rested his forehead on the bars. ‘I will not help you break the enchantment,’ he said softly, so softly I almost did not hear him. ‘I love Ceinwyn, but if Ceinwyn must suffer for the Gods, then she is doing a noble thing.’

‘Lord,’ I began to plead.

‘No!’ He shouted so loudly that in the encampment behind us some dogs howled in reply. ‘No-,’ he said more quietly. ‘I compromised once and I will not compromise again, for what was the price of compromise? Suffering! But if Nimue can perform the rites, then all our suffering will be done. Soon be done. The Gods will return, Ceinwyn will dance and I shall see.’

He slept for a while and I slept too, but after a time he woke me by putting a claw-like hand through the bars and seizing my arm. ‘Are the guards asleep?’ he asked me.

‘I think so, Lord.’

‘Then look for the silver mist,’ he whispered to me.

I thought for a heartbeat he had slipped back into madness. ‘Lord?’ I asked him.

‘I sometimes think,’ he said, and his voice was quite sane, ‘that there is only so much magic left on the earth. It fades like the Gods fade. But I did not give Nimue everything, Derfel. She thinks I did, but I saved one last enchantment. And I have worked it for you and for Arthur, for you two I loved above all men. If Nimue fails, Derfel, then look for Caddwg. You remember Caddwg?’

Caddwg was the boatman who had rescued us from Ynys Trebes so many years before, and the man who had hunted Merlin’s piddocks. ‘I remember Caddwg,’ I said.

‘He lives at Camlann now,’ Merlin said in a whisper. ‘Look for him, Derfel, and seek the silver mist. Remember that. If Nimue fails and horror comes, then take Arthur to Camlann, find Caddwg and look for the silver mist. It is the last enchantment. My last gift to those who were my friends.’ His fingers tightened on my arm. ‘Promise me you will seek it?’

‘I shall, Lord,’ I promised him.

He seemed relieved. He sat for a time, clutching my arm, then sighed. ‘I wish I could come with you. But I can’t.’

‘You can, Lord,’ I said.

‘Don’t be absurd, Derfel. I am to stay here and Nimue will use me one last time. I might be old, blind, half mad and nearly dead, but there is still power in me. She wants it.’ He uttered a horrid little whimper. ‘I cannot even weep any longer,’ he said, ‘and there are times when all I wish to do is weep. But in the silver mist, Derfel, in that silver mist, you will find no weeping and no time, just joy.’