Career criminals and Old Etonians aside, people generally like their police to take control of whatever situation they find themselves in. You don’t call the police unless things have already gone pear-shaped, and it’s nice to have a group of people you can shunt all the responsibility onto. As police, how you assert control ranges from hitting people with an extendable baton through making everyone speak slowly and clearly, to asking them to make you a cup of tea in their own kitchen.

The last being what I did that evening and soon Ethan had his dinner, Hannah was fetched in from the garden, I got a cup of tea, and we all sat around the kitchen table in a calm and productive manner.

‘Tell Peter what you told me,’ said Joanne.

Hannah screwed up her face.

‘Do I have to?’ she asked.

‘Yes, you do,’ said her mum.

‘But I want to watch TV.’ She slumped in her chair and started sliding off it by inches.

‘Hannah,’ said Andy gently. ‘Just you tell Peter here what you know and then you can be off.’

At her dad’s words, Hannah reluctantly straightened up and, after a great sigh, looked straight at me.

‘Nicky isn’t Nicky,’ she said. ‘She’s somebody else.’

The drama of the moment was somewhat undercut by Ethan, who demonstrated a new mastery of the mysteries of angular momentum by banging his hand down hard on the edge of his bowl, causing it to cartwheel off his tray and create a, no doubt interesting to him, Catherine-wheel effect with his dinner.

The resulting scolding, cleaning and fussing at least gave me a chance to try and think of something more sensible to say than, Are you sure? Of course she was sure, I could see that in the set of her face. But what did she mean? I was willing to believe that families ran a bit different in the countryside, but I doubt it went as far as Victoria accepting a strange child as her own. Presumably, the Nicole currently recuperating at the Lacey house looked and sounded like the one who had gone missing ten days before.

‘How can you tell?’ I asked Hannah while her parents were distracted.

‘Just can,’ said Hannah.

‘But she looks the same?’

‘Looks the same, yeah,’ she said. ‘But she isn’t the same.’

I asked about clothes, dress, speech, smell – which made Hannah giggle – but she couldn’t give me a single bit of verifiable evidence that Nicole Lacey was anyone other than Nicole Lacey. Not that Hannah knew who the imposter could be.

‘Just isn’t Nicky,’ she said stubbornly.

When the brothers came in from the darkening garden it seemed prudent to release Hannah to watch TV. She shot off, and I found myself sharing a table alone with Andy as Joanne put Ethan to bed.

‘Is it a good job, policing?’ he asked.