‘Mine, Lola’s and Cressida’s.’ Her face was pale as she added quietly, ‘Chloe’s is gone.’

The uniformed policewoman rose and started to speak brusquely into a wireless handset fixed to her shoulder.

‘Now, Mrs Firbank,’ said the detective sergeant, ‘we need to know why exactly your children have their own passports? Was it to visit anyone in particular?’

Imogen shot Theresa a look. ‘It was her idea. For some ridiculous reason she now lives in France, when she could have lived around the corner here in London. Then she had the bright idea that, if the children ever needed to travel over to see her, it would be easier if they had their own travel documents.’

Theresa winced from the unfairness of the attack. She recalled that once, when she had suggested moving to live round the corner, Imogen had made a cruel remark: ‘Better to keep a bit of distance. After all, we don’t want you spying on us.’ It had been the tipping point in her decision to move to France.

When Theresa looked up she saw that the detective sergeant was silently surveying her.

‘Clearly you are not in France, Mrs Simmonds. Therefore, I presume your grandchild isn’t currently paying you a visit.’

Theresa didn’t know how to respond. ‘I left as soon as I heard what had happened. Today. Early afternoon.’

‘Do you live alone in France?’

‘Yes. I have a small flat on the Côte d’Azur.’

‘In Southern France, I believe? A few miles from Nice, is that right?’

‘Yes.’

‘Does Chloe have a key to the flat?’

‘No. She did ask me on the phone the other day whether Bellevue-sur-Mere was in the Riviera. At the time it didn’t seem to mean anything, but maybe it did . . .’

‘No one else lives with you?’

‘Not with me. It’s the lower part of a maisonette. There are people in the flat above mine. But it has a separate front door. It’s an occasional short-holiday let. But my flat is currently empty.’

The detective nodded and returned to her notes.

‘Mrs Firbank, do you have any connections with these other places your daughter referred to: Spain, Sardinia?’

Imogen sighed and said no.

‘Returning to the subject of this man, Laurence. Your other daughter told you he was seen before Christmas at the school which they attend, and of which you are headmistress?’

‘That’s right,’ said Imogen. ‘I presume she meant in the playground rather than the school building. But I cannot think that a strange man, lurking in a school playground wearing a brown dress, would not have been reported to me by one of the supervising staff.’

‘And do you have any idea how they met?’

Theresa decided to put forward her theory. ‘Cressida told me his name was Fire. I’m wondering if that isn’t one of those internet names from a gaming site?’

‘Interesting.’ The detective scribbled again in her notebook and said, ‘I realise that it’s very late now to wake the other children but I’m sure you realise that time is of the essence . . .’