We followed a winding road through dense woods alongside a deep valley, then came to a town split on either side of the river Thames, which we crossed by a hump-backed bridge with the county sign displayed to one side: OXFORDSHIRE.

This was Henley, which was all pretty church towers and old, sash-windowed houses. It looked like one of the illustrations in the book of fairy tales I’d had when I was younger, of the magical town at the bottom of a lake. Everybody who belonged there carried on their business as usual, but outsiders couldn’t visit without drowning. That was the countryside for you: pretty, but not necessarily welcoming.

The town thinned out and we drove along a broad tree-lined avenue and then we were back in woodland, miles and miles of it. Eventually we descended a steep hill and passed a few low, straggly-looking cottages and a sign for Fairmarsh, and Mum said, ‘Nearly there.’ She turned off the main road and drove along a lane with a high hedge on one side and farmland on the other, and then we turned off at the sign for Fairmarsh Place and followed a narrow road through prettily landscaped grounds, shaded by a mixture of grand old trees.

‘Made it,’ Mum said as we pulled up in a parking space in front of a huge and rather intimidating red-brick Victorian building.

I recognised it immediately, even though I’d never been there in the flesh before.

I’d seen it in that dream I’d had that first night in France. It was built in an E-shape, with wings to either side and a grand, porticoed entrance. It looked like the kind of house that might have featured in one of the old classic novels that Mark had given us. A fitting home for a vengeful, ancient bride, or a locked-up wife. Or ghosts.

‘It’s huge,’ I said.

‘It’s all broken up into flats, silly,’ Ava said. ‘Mum, didn’t you say it used to be a loony bin?’

‘Don’t call it that,’ Mum said. ‘It’s a former mental hospital. You should watch what you say, because Mark’s dad used to work here, and so did his grandfather – Ingrid’s father. Ingrid’s father ran the place for years, and Mark’s dad was one of his assistants, which was how Ingrid met him.’

‘Mark’s dad died in a car crash, right?’ Ava said. ‘Under slightly suspicious circumstances.’

‘Not that suspicious. There was an inquest, and the coroner said it was an accident. His car hit a tree. But anyway, it was obviously very upsetting, so best not to mention it. His state of mind hadn’t been brilliant beforehand, not surprisingly – after all, I should think it’s a very stressful line of work. So there were some lingering doubts, for Mark at least, which the coroner’s verdict didn’t really resolve. Also, just so you know, Ingrid had a sister – Mark’s aunt – who had problems, and spent years actually as a patient at the hospital before she was moved out when it closed. Mark only found out about her after she’d died, which was back before you were born, Ava. Probably best not to mention her, either.’