‘I’m still puzzled,’ she said. ‘Why are you so interested in all this?’

‘It’s quite simple. I’ve heard an account of the night from a family member, and for some reason they left you out of the picture. Completely. And I would like to know why that was, and what you saw that led to this denial of your presence.’

A faint smile in response. ‘I was a ghost at the feast. If feast it was.’

He could see her excitement at this prospect, of Hobbes investigating a mystery from her life. And now she carried on freely.

‘Leonard took me back downstairs. I don’t think the sister, Rosamund … She wasn’t there. But she appeared later on. And we drank some more. I imagine we were all tipsy by then. Oh, yes, at one point I walked out into the back garden. I had gone into the kitchen on my own, to get a glass of water. The back door was open, so I stepped outside. Gardens have always held a magical power for me. I remember now, walking down to the wild area, near the rear wall, and looking back at the house. There was …’

Hobbes leaned forward. ‘Yes?’

‘There was someone at the top window. No … two people. Two women, I think. What a strange thing to remember.’

‘Not at all. Little details often come back to us, far more than the larger events.’

And he remembered Camilla’s story of standing next to Adeline, in her bedroom, and the ghostly figure they had seen in the garden below. How very alike Adeline Graves and Jeannie Watts must have looked, in such circumstances, moonlit, on an October evening: one young woman a bearer of her grandmother’s great beauty, and the other chosen purely for her resemblance to Mary Estelle Graves. It was uncanny.

An idea formed in Hobbes’s mind. It was so strange a thing, he could hardly pursue it, for fear it might break apart.

Jeannie Watts was still talking: ‘I went back inside, back to the party. I must have spent some time chatting with Mary Estelle, or trying to, asking for her advice on my career. That’s the kind of thing I would have done, given my purpose back then. I was very keen on getting on in life, escaping my loneliness.’

Hobbes knew he was approaching the key moments. ‘Jeannie, tell me if you can. Was there anybody else at the party, someone you haven’t mentioned yet?’

She took a breath. ‘There was, yes. I was coming to that.’

‘Who was it?’

‘It was a young woman. She came into the room much later on, when we were all quite drunk. I can remember her now, standing at the doorway, looking at us all in turn.’

Hobbes held his breath, as he waited for the story to unfold.

‘I didn’t know who she was, this new arrival, not to begin with. But I picked up that she was Mary Estelle’s third daughter.’