A four-bedroom  new build in the 1990s, assembled from unremitting pale brick and still looking like an architectural  drawing, it hadn’t weathered. Its profile was low, yet it was clearly not a bungalow. There was a patio like a hard standing for machinery. The white lattices of security grilles, which from a distance looked as if they had been taped on, divided every window. Sunshine glittered off the clutter of photovoltaic and hot water panels set into the shallowly-sloping roof. The only character it possessed lay at the end of its long asymmetric garden: a few trees inherited from some previous, more authentic dwelling on the site. Something resembling life would be lent it each spring by the energetic scraping conversations of the starlings that nested in its gutters. Otherwise, it reminded  Anna of a cheap toy abandoned  on a carpet; something unable to age because of the sheer purposive artificiality of the materials used to construct  it. If it was familiar, she realised, that was because it was her own house.

‘I’m not sure I like it any more,’ she told Dr Alpert that afternoon.

‘I can’t explain why.’

But she could. Too many rooms like plaster boxes. Too much furniture  that  had  aged but  somehow  never  gained  character. Clothes she longer wore. A car she never drove. It was less a house than a place to store things.

‘Every room is a box-room,’ she complained.

‘Are you sure it’s your house we’re talking about?’

Anna laughed. ‘I have three toilets,’ she said. ‘One in the en suite, one in the house bathroom and one downstairs. Who needs three toilets? I wake up at night wondering which one to use and wishing I lived in a single room  again. I know exactly what I’d want. I often imagine it.’

Dr Alpert was interested in that.

‘Tell me about the room you imagine,’ she said.

‘Why?’

Because it’s been a slow session, the doctor  thought,  and we might as well have met for tea somewhere instead. Because a wet afternoon had followed the promise of the morning. Because, she thought – glancing out of the consulting-room window at Chiswick Eyot, then down at her desk where the open case file, a vase of pale yellow narcissi and a box of Kleenex lay like something more than themselves in a clear puddle of watery light – the Thames is up as high as the road and nothing is drearier than rain on the tideway. Because today you seem like such a nice ordinary woman.

‘Because it’s interesting,’ she said. ‘Oh come on, Anna, what fun!’