‘I like sweetcorn.’ My smile is real, when I remember Alice trying to brush it off me, afterwards. ‘There’s nobody – I’m good on my own.’ I take a rectangle of shortbread, nibble on it. ‘Can I use your loo?’ I hear how abrupt the question is.

‘Of course.’ She directs me. ‘Don’t get lost. Everyone does.’

I laugh too. ‘I never get lost.’ Though this time I plan to.

I deliberately miss the ground-floor cloakroom that she told me about, instead passing through huge rooms that seem to dissolve into one another. There is nothing personal in any of them. No discarded shoes or toys. No dust anywhere. It is as if this house is a giant hotel, a place straight out of Zac’s dreams. My trainers squeak with every step, and I make a quiet note to myself that trainers on marble are not good.

I climb the stairs to the first floor, where I find two master bedrooms, each with its own sitting room and bathroom. They make me think of castles where the king and queen each had their separate quarters, though the king would visit his lady’s chambers on occasion. Is this the kind of arrangement Eliza and Zac have? It is difficult to imagine Zac wanting that.

In Eliza’s room is a framed collage of photographs, the first intimate thing I have found in this house. It sits on a dressing table that is made entirely of mirrors. I snap a photo of the collage as fast as I can, knowing I will study it more closely later.

For now, I cannot let myself react to what I see. Eliza holding Alice at a few weeks old, looking blissfully pleased with herself, as I would have. They are both wearing white eyelet sundresses, a mother and her mini-me dressed as angels. My heart is pounding, and I press my lips together.

It pounds harder still at the photograph of Zac, holding an older baby Alice at about six months. He does not look happy, though he is standing in a playground, holding his child beneath a maple tree so heavy with red leaves it resembles a firecracker.

I am increasingly disinclined to agree with Maxine that Eliza doesn’t know who I am. How can she not? But if she does, why doesn’t she say? I shake my head. My thoughts seem to shake with it, in a confused jumble. Again, I ask myself if Eliza engineered that appointment at the hospital. Then I remind myself that Alice’s condition is real – Maxine was right to say that the need for her to be examined regularly at that clinic is an absolute.