It takes more effort than usual to get my bearings in this seeming labyrinth, as we descend to the basement, where there is a kitchen that is twice the size of my flat. One wall is made entirely of glass, and opens into a huge garden that slopes gently downwards.

I rummage in my bag, then hand her the bottle of iron. ‘It’s in liquid form. She’ll absorb it best if you give her some juice and food with it. Oh – and avoid milk if you can, close to when she takes it. There are instructions on the bottle label.’

‘Do you do this for every patient?’ Eliza smooths her already-smooth dark hair. I’m struck by her dark eyes, which are huge and lovely but so unlike Alice’s.

‘Only the special ones. And their mums. But her iron is very low – the doctor wants her started on this.’

‘As soon as she finishes her nap.’ Eliza’s face is radiant. ‘Did you know her hearing test was perfect?! We’re in the lucky forty per cent. I knew we would be!’

I do know, because I looked up Alice’s result, but all I say is, ‘That’s wonderful news.’ And it is, because the majority of those with type I Waardenburg syndrome have hearing loss.

‘We had so much fun last night, Helen.’

‘I think she got more of the toppings on herself than the pizza base.’

‘Well, I was so tired. I can’t tell you how much that little break meant. Sitting and enjoying a glass of wine while someone else entertained Alice. You absolutely enchanted her. I hope she didn’t exhaust you.’

‘Not at all.’

While Eliza busies herself with the cafetière, I climb onto a high stool at the breakfast-bar end of a granite-topped island. There is a row of old servants’ bells on the wall, with an oval plaque underneath each one to indicate where the call is coming from. North Bedroom. Blue Tapestry Room. Dining Room. Study. Library. The Red Room. The Cabinet Room. Picture Gallery. The Chapel. Grey Dressing Room.

‘Most of the rooms those bells rang in are long gone.’ Eliza is arranging biscuits on a stoneware plate. ‘Our house is the sole surviving wing of a once-grand mansion. The wing was a late nineteenth-century addition.’

‘It still seems pretty grand to me.’

She laughs. ‘The central building and the other wing burned down in 1904. There was parkland, these huge grounds, but they sold most of it off and built on it. There’s a bit of the original garden left.’ She points to the right of her own garden, where the tops of several trees are visible on the far side of a tall brick wall. ‘Over there. Do you see?’

‘Yes.’

‘It belongs to the city, now. I love taking Alice there for walks and picnics.’ Eliza smiles at the flowered paper bag I’ve laid on the table. ‘What’s that?’

‘Oh. A little something I thought Alice might enjoy.’