‘Who rules Britain?’ she asked me abruptly.

‘The wrong question!’ Merlin snapped at her with unexpected vehemence, ‘the wrong question!’

‘Well?’ she demanded of me, ignoring Merlin’s anger.

‘No one rules Britain,’ I said.

‘The right answer,’ Merlin said vengefully. His bad temper had unsettled Gawain, who was standing behind Merlin’s couch and looking anxiously at Nimue. He was frightened of her, but I cannot blame him for that. Nimue frightened most people.

‘So who rules Dumnonia?’ she asked me.

‘Arthur does,’ I answered.

Nimue gave Merlin a triumphant look, but the Druid just shook his head. ‘The word is rex,’ he said, ‘rex, and if either of you had the slightest notion of Latin you would know that rex means king, not emperor. The word for emperor is imperator. Are we to risk everything because you are uneducated?’

‘Arthur rules Dumnonia,’ Nimue insisted.

Merlin ignored her. ‘Who is King here?’ he demanded of me.

‘Mordred, of course.’

‘Of course,’ he repeated. ‘Mordred!’ He spat at Nimue. ‘Mordred!’

She turned away as though he was being tedious. I was lost, not understanding in the least what their argument meant, and I had no chance to ask for the two children appeared through the curtained doorway again to bring more bread and cheese. As they put the plates on the floor I caught a hint of sea smell, that waft of salt and seaweed that had accompanied the naked apparition, but then the children went back through the curtain and the smell vanished with them.

‘So,’ Merlin said to me with the satisfied air of a man who has won his argument, ‘does Mordred have children?’

‘Several, probably,’ I answered. ‘He was forever raping girls.’

‘As kings do,’ Merlin said carelessly, ‘and princes too. Do you rape girls, Gawain?’

‘No, Lord.’ Gawain seemed shocked at the suggestion.

‘Mordred was ever a rapist,’ Merlin said. ‘Takes after his father and grandfather in that, though I must say they were both a great deal gentler than young Mordred. Uther, now, he could never resist a pretty face. Or an ugly one if he was in the mood. Arthur, though, was never given to rape. He’s like you in that, Gawain.’

‘I am very glad to hear it,’ Gawain said and Merlin rolled his eyes in mock exasperation.

‘So what will Arthur do with Mordred?’ the Druid demanded of me.

‘He’s to be imprisoned here, Lord,’ I said, gesturing about the palace.