I’m racing through the implications of this, trying to be calm and rational and drive safely when my heart is pounding so hard it seems to be echoing in my own ears.

If Eliza Wilmot was menopausal before Alice was born, she cannot be her biological mother. She could have used a donor egg, but that makes no sense, given that there’s little doubt that Zac is Alice’s father. It is one thing to believe he accidentally got Eliza pregnant during an affair while he was with me, quite another to imagine he actively participated in her fertility treatment in the way a partner would – though I can’t entirely discount the possibility.

Was Eliza ever really pregnant? Could Alice – must she – be mine? Those stories I’d found of stillborn babies swapped with living ones, and forced adoption, and the kidnapping of newborn babies. I’d tried to tell myself it was part of my mad grief, my wish for it not to be true that my baby was gone, my inability to accept it. I don’t know what all of this might mean for Alice. Until I do, I don’t want her put at risk by having it known. ‘Have you kept any records of this, George?’

‘No.’

‘Do you feel you need to?’

He pauses. ‘Do you feel I should feel I need to?’

I laugh, astonishing myself that I still can. ‘I’m not sure yet.’

‘Then neither am I.’

‘Why are you doing this for me?’

‘Because when you tried to help us, you got badly hurt. It’s the least we – I – can do.’

‘What do you want from me?’

‘Me, nothing. Maxine—’ Do I imagine that he chokes back whatever he’d been about to say, as if the idea of it made him uncomfortable? ‘As she said, she’ll speak to you later. Where are you, Holly?’

‘Visiting an old friend.’

‘Tell me where you are. Please.’

‘It’s not as if you can’t figure it out, George. Uh-oh. I seem to be losing the signal.’ And I cut off the call.

It is dark by the time I reach Thorpe Hall, which sits below the main road in a little valley. I leave my car at the top of the narrow lane that leads to it, then walk down, lighting the way with my phone torch, which I switch off when I am close.

The ground is boggy, presumably from the run-off that must come from above. It looks as if the whole decaying house is about to be swallowed in a huge, quick-sanded gulp. I know from the map that behind the house is moorland, which ends at the cliffs about half a kilometre from the back garden.