‘It was a little like hide-and-seek.’ Her hands twisted the tumbler. ‘Evangeline would always hide first – an elder sister’s privilege – and I used to wait on the red-backed chair in the hall. If you look you will see the loose thread I used to pick at when I grew bored. I would shut my eyes tight.’ She blinked hard. ‘Sometimes, sitting there, I would hear nothing but the creak of the boards on the landing and the sound of servants far off. I would wait and wait and then I had to go up the stairs and listen. When the time was up, Evangeline had to whistle. My uncle taught us, although my parents forbade it as unseemly.’ Her eyes flashed. ‘I think that added to its appeal. I would start at the top of the house and listen so hard until I heard her. The rules were that we would whistle twice, every five minutes or so, until we were found.’ She looked at me curiously. ‘Did you and Clara play together as children?’

I was back instantly with the hot square of sun that came through the glass in the window seat of the parlour. And the weight of her slight frame as she leaned against me while I read from some adventure book.

I nodded.

‘Evangeline was easy to find. I was always the cleverer.’ Her chin lifted. ‘One day, her whistle took me hither and thither. Strictly speaking, the rules of the game forbade us moving from spot to spot. I was so cross. It led me finally to the old servants’ wing, which was out of bounds. We were not really supposed to go into their quarters, but during the day they were empty and so I went in. The whistle took me up to the attic where rooms were used as storage.’ She gazed into the distance. ‘I remember clambering between the dusty boxes and crates to stand at the window. The windows are tiny up there, no bigger than a handkerchief.’ She finished her drink and her hand strayed to the decanter again. ‘I remember looking out and wondering what lay beyond the sea and believing that one day, I should find myself living in some grand house in Edinburgh with a family of my own.’ Her fingers went unconsciously to her cheek. ‘Of course that wasn’t to be.’

‘Was your sister there?’ I asked.

She turned to me as if she had forgotten that I was present. ‘I heard the whistle again and rustling, something moving between the boxes. Of course, I knew it was Evangeline. I was angry by then. She had broken the rules. “Just come out,” I said, “or I’ll tell Mama that you came up here.”’ She paused again. ‘But it was the strangest thing, Elspeth – the whistle came again but it was not my sister’s. It sounded – it sounded like a flute or a pipe.’

I went cold.