‘He must, Lord, for what other use is God? But God, of course, may have other ideas. It is so very hard to read His mind.’ The Bishop was now warm enough to risk shedding the big cloak of bear fur from his shoulders. Beneath it he wore a sheepskin jerkin. He put his hand inside the jerkin and I assumed he was scratching for a louse, but instead he brought out a folded parchment that was tied with a ribbon and sealed with a melted drop of wax. ‘Arthur sent this to me from Demetia,’ he said, offering me the parchment, ‘and asked that you should deliver it to the Princess Guinevere.’

‘Of course,’ I said, taking the parchment. I confess I was tempted to break the seal and read the document, but resisted the temptation. ‘Do you know what it says?’ I asked the Bishop.

‘Alas, Lord, no,’ Emrys said, though without looking at me, and I suspected the old man had broken the seal and did know the letter’s contents, but was unwilling to admit that small sin. ‘I’m sure it is nothing important,’ the Bishop said, ‘but he particularly asked that she should receive it before the solstice. Before he returns, that is.’

‘Why did he go to Demetia?’ Ceinwyn asked.

‘To assure himself that the Blackshields will fight this spring, I assume,’ the Bishop said, but I detected an evasion in his voice. I suspected the letter would contain the real reason for Arthur’s visit to Oengus mac Airem, but Emrys could not reveal that without also admitting that he had broken the seal.

I rode to Ynys Wydryn next day. It was not far, but the journey took most of the morning for in places I had to lead my horse and mule through drifts of snow. The mule was carrying a dozen of the wolf pelts that Cuneglas had brought us and they proved a welcome gift because Guinevere’s timber-walled prison room was full of cracks through which the wind hissed cold. I discovered her crouched beside a fire that burned in the centre of the room. She straightened when I was announced, then dismissed her two attendants to the kitchens. ‘I am tempted,’ she said, ‘to become a kitchenmaid myself. The kitchen is at least warm, but sadly full of canting Christians. They can’t break an egg without praising their wretched God.’ She shivered and drew her cloak tight about her slender shoulders. ‘The Romans,’ she said, ‘knew how to keep warm, but we seem to have lost that skill.’

‘Ceinwyn sent you these, Lady,’ I said, dropping the skins on the floor.