I twisted to look at the shore but it was too far away. I did not even know if Mary could swim.

‘Why?’

‘I would have put up with an affair, but she was going to give Robert what he most wanted – a child.’ And behind the kindly lines of her face, another showed, cut with grief and bitterness.

‘I thought it was Paterson,’ I said.

‘She could have had any man she wanted – she may have slept with Paterson but it was Robert who lost his heart and gave her what I wanted with all mine.’

‘And William saw you?’

‘They were evil. Skelthsea was better without them.’ She took up the oars again.

‘Let us go,’ I said. ‘Take us to the boat. I won’t tell. I’ll never tell.’

The slip of the wood through the water was her only answer and a new terror clutched at me.

‘Tell me that there is a boat,’ I said.

‘No boat. This is it.’

‘I cannot believe this of you. Please.’

But suddenly Mary stood, rocking the vessel, her face creased with fury.

‘They were never evil. He was not bad. She’s lying, Elspeth. Hettie was good and William was good. Hettie protected us. She made it up.’

Bridget’s lips tightened. ‘Hettie was a whore!’

‘You made them look bad. William never hurt a creature – never in his life. He loved them. And Hettie, Hettie was kind.’ Tears began to fill her eyes and I turned to Bridget in horror and disgust.

‘You did those things? You made it so that everyone thought it was William and Hettie.’ And I was assailed with a sudden hopelessness. I thought of all the conversations she had fed with lies until I was so full of them it left no space for truth. If Bridget was capable of that then there could surely be no part of her that I could reach. I pulled Mary to my side.

Bridget shrugged and I was mesmerized by the strong rhythm of her shoulders and how the boat went relentlessly on.

‘I thought,’ she said finally, ‘if I made it so that she was wicked, that Robert would leave her alone. Although his flesh is weak his moral spirit is strong. He could not have bedded a witch.’

I felt sick. ‘Stop now,’ I pleaded. ‘Take us back. Haven’t you caused enough pain, Bridget? I thought you were my friend.’

‘And so I am.’

But the blank stare she returned showed me the truth. She did not care. And then behind us there was a shout. I turned. A figure scrambled across the rocks, hair loosed down her back. ‘Stop,’ she yelled, ‘I won’t lie for you any longer.’

And I realized, with shock, that it was Greer.

She stood, her face white in the semi-darkness, clutching her hands as if in despair and a spark of hope lit my chest.