This is a valley, I told myself, in upland Powys. A hidden place where a desperate man might find shelter. The hoop of time did nothing here, I assured myself, yet even so I felt a shiver of apprehension as Olwen took me down to the huts beside the lake where the army camped. I had thought the folk here must be sleeping, for we were deep into the night, but as we walked between the lake and the huts a crowd of men and women swarmed from the huts to watch us pass. They were strange things, those people. Some laughed for no reason, some gibbered meaninglessly, some twitched. I saw goitred faces, blind eyes, hare lips, tangled masses of hair, and twisted limbs. ‘Who are they?’ I asked Olwen.

‘The army of the mad, Lord,’ she said.

I spat towards the lake to avert evil. They were not all mad or crippled, those poor folk, for some were spearmen, and a few, I noticed, had shields covered with human skin and blackened with human blood; the shields of Diwrnach’s defeated Blood-shields. Others had Powys’s eagle on their shields, and one man even boasted the fox of Siluria, a badge that had not been carried into battle since Gundleus’s time. These men, just like Mordred’s army, were the scourings of Britain: defeated men, landless men, men with nothing to lose and everything to win. The valley reeked of human waste. It reminded me of the Isle of the Dead, that place where Dumnonia sent its terrible mad, and the place where I had once gone to rescue Nimue. These folk had the same wild look and gave the same unsettling impression that at any moment they might leap and claw for no apparent reason.

‘How do you feed them?’ I asked.

‘The soldiers fetch food,’ Olwen said, ‘the proper soldiers. We eat a lot of mutton. I like mutton. Here we are, Lord. Journey’s end!’ And with those happy words she took her hand away from mine and skipped ahead of me. We had reached the end of the lake and in front of me now was a grove of great trees that grew in the shelter of a high rocky cliff.

A dozen fires burned under the trees and I saw that the trunks of the trees formed two lines, giving the grove the appearance of a vast hall, and at the hall’s far end were two rearing grey stones like the high boulders that the old people erected, though whether these were ancient stones, or newly raised, I could not tell.

Between the stones, enthroned on a massive wooden chair, and holding Merlin’s black staff in one hand, was Nimue. Olwen ran to her and threw herself down at Nimue’s feet and put her arms about Nimue’s legs and laid her head on Nimue’s knees. ‘I brought him, Lady!’ she said.

‘Did he lie with you?’ Nimue asked, talking to Olwen but staring fixedly at me. Two skulls surmounted the standing stones, each thickly covered in melted wax.