‘I believe Mrs Argylle wanted Miss Gillies to send her away,’ she continued. ‘Although she killed William, I believe it did not sit well with her. And if you had not interfered, it would have happened sooner and Mary would have been safe.’

‘Safe? Safe in an asylum? Condemned to a diagnosis of insanity? Miles from friend or family?’

She regarded me stonily.

‘You could have made a friend of me, Greer. I would have helped.’

‘Make a friend of you? I saw the way you looked at me, just like the rest with all your bookish ways. What would you have said if I told you about the widows’ whistle or murder?’

Shame seeped through me. She was right. The glass rattled in its frame as the wind rushed outside. She leaned forward and I caught some of her rage. ‘But you sent them away. It was you, wasn’t it? I saw your fear when my Hettie returned, and then I saw your triumph when she had gone.’ There was a rent in her voice and I glanced away.

‘And now?’ I said.

She stood and began to comb her hair. She moved slowly and without haste, as she might at the end of any day, her feet solid on the boards, her fingers measured.

‘I don’t intend to tell Miss Gillies of tonight’s events, or your part,’ I said. ‘What the island will surmise if Bridget’s body washes up, I do not know.’

‘It will not.’ And there was a certainty to her look. that I did not question I put my hand into my pocket and drew out the whistle. It lay light on my palm, innocuous. It was hard to imagine how much could be achieved by the mere blowing of it.

‘This belongs with you, Greer. I believe you would not use it ill.’

Her eyes widened and, slowly, she nodded.

I waited, but she began taking out her night things. She did not want me there.

‘Thank you, Greer,’ I said and went to the door.

But as I pushed it open, I hesitated and retraced my steps. She faced me then and stilled. I went up to her and put a hand on her arm. It was warm and smooth and I saw the darker flecks in her irises. ‘You’re too good for Paterson. We could be friends now, Greer, couldn’t we?’

She regarded me and some of her hostility came to rest in her eyes. ‘Goodnight, miss,’ she said.