Vortigern leaned forward, chin on fist. “Merlin, we have learned today what in part we already suspected, that you are the child of no man, but of a devil. As such, you require mercy from no man. But because your mother is a king’s daughter, and therefore something is due to you, I shall tell you why I brought you here. You know perhaps that I am building a stronghold here on the rock they call the Fortress?”

“Everyone knows it,” I said, “and everyone knows it will not stand, but falls down whenever it reaches man height.”

He nodded. “And my magicians and wise men here, my advisers, have told me why. The foundations have not been properly laid.”

“Well,” I said, “that sounds remarkably like sense to me.”

There was a tall old man to the King’s right, beside the priests. His eyes were a bright angry blue under jutting white brows. He was watching me fixedly, and I thought I saw pity in his look. As I spoke, he put a hand up to his beard as if to hide a smile.

The King seemed not to have heard me. “They tell me,” he said, “that a king’s stronghold should be built on blood.”

“They are talking, of course, in metaphors?” I said politely.

Maugan suddenly struck his staff on the floor of the dais. “They are talking literally!” he shouted. “The mortar should be slaked with blood! Blood should be sprinkled on the foundations. In ancient times no king built a fortress without observing this rite. The blood of a strong man, a warrior, kept the walls standing.”

There was a sharp pause. My heart had begun to beat in slow, hard strokes that made the blood tingle in my limbs. I said, coldly: “And what has this to do with me? I am no warrior.”

“You are no man, neither,” said the King harshly. “This is the magic, Merlin, that they have revealed to me, that I should seek out a lad who never had a father, and slake the foundations with his blood.”

I stared at him, then looked round the ring of faces. There was shifting and muttering, and few eyes met mine, but I could see it in all their faces, the death I had smelt ever since I entered the hall. I turned back to the King.

“What rubbish is this? When I left Wales, it was a country for civilised men and for poets, for artists and for scholars, for warriors and kings who killed for their country, cleanly and in daylight. Now you talk of blood and human sacrifice. Do you think to throw modern Wales back to the rites of ancient Babylon and Crete?”

“I do not speak of ‘human’ sacrifice,” said Vortigern. “You are the son of no man. Remember this.”