‘But we don’t know if she survived the attack on the crannog.’ She sighs, then a terrible thought occurs to her. ‘Lucas said something about the body in the grave at the dig. He said that sometimes people were buried with heavy stones on top of them if they were thought to have been witches. When the crannog was inhabited, would someone who had visions have been thought of as a witch?’

‘A difficult question to answer. The custom of foretelling the future is such an ancient one, and one that is found in so many diverse cultures. The early Celts certainly had their shamans, and they were important people, but seeing the future was not seen as magic. More a talent, or a gift.’ He gives a chuckle. ‘They might perhaps have been viewed more as our weather forecasters are today.’

‘So not witches, then?’

‘Ah, well, witches abound in Celtic literature and many other ancient Welsh stories. And there is nothing to say a Seer cannot also be a witch.’

Tilda feels suddenly weary. She drains her glass, letting the syrupy sherry pleasantly ease her tangled thoughts. ‘I’m beginning to think the more I find out, the less I understand.’

At this, the professor laughs more heartily. ‘My dear girl, welcome to the world of the historian!’

Dylan has returned to stand at Tilda’s elbow.

‘Is my uncle making your brain ache?’

‘He’s trying to help, but I can’t expect sensible answers if I can’t even form reasonable questions,’ she tells him, running a hand through her hair.

‘Perhaps another sherry would help?’ Professor Williams suggests.

‘Wow.’ Dylan is horrified. ‘No wonder you’re struggling. Sit yourself down. Lunch will be ages yet. I’ll open a decent bottle of wine, and between us surely we can work out what it is you need to know. Okay?’

Half an hour later, at Dylan’s insistence, Tilda has made a list. She is reluctant to read it out.

‘It looks even crazier written down.’

The professor smiles. ‘If I have learned anything from my years of study, it is that what at first appears incredible, often, when looked at from the correct angle, comes to seem entirely plausible.’

Tilda can’t help wondering if his credulity would stretch far enough to believe what happens to her when she wears the bracelet.

Dylan gently takes the list from her. ‘Let me,’ he says. ‘First up, who was the woman in the boat, and is she the same as the woman you saw the other day when you put on the bracelet?’

Tilda grimaces. ‘See, I told you.’ She glances at the professor.

Here goes nothing. If I want him to help me I’m going to have to tell him.