‘If you do think of anyone please let me know because that person will have to be fingerprinted too.’

‘She said nobody, didn’t you hear her?’

‘Jeff . . .’

‘It’s all right, I understand. You have to say whatever you need to.’ Serrailler got up. ‘Mrs Tonks, is there anyone you can ask to come and stay with you tonight? You shouldn’t be on your own.’

‘I’ll be all right.’

‘I’ll stay,’ Jeff Tonks said. ‘This is about our daughter. Hers and mine. Of course I’ll stay. What do you take me for?’

Simon’s phone rang a few minutes after eight the next morning.

‘You can come and ask whatever you like, I’m all right now.’

‘Did you get some sleep?’

‘No but that’s not the point, as I said. Just let’s get it over with.’

‘Is your hus—’

‘Jeff’s gone now.’

If anything, Greta Tonks looked worse, when she opened the door, her face grey, and aged twenty years overnight. She offered him coffee but this was a time for getting on and getting out, though he sat down, to help her relax more than to settle down.

He asked the questions tactfully but more formally now, feeling this to be another day, separated in some way from the one in which it had all happened. However sleepless it had been for them, the night had moved them one step on. Now they would say ‘yesterday’ instead of ‘today’.

Greta had precious little to tell him. She knew Olivia’s close friends, gave him names and details, but she could tell him nothing else about how matters had been between Liv and any of them. She talked about school, where the girl seemed to have had no problems, about her dance classes, her sports, her possible GCSE subjects. A bit more about her relationship with her father. But if Olivia had had secrets, they had been exactly that.

It was over in half an hour.

‘Just one last thing, Mrs Tonks. Do you know where Olivia’s phone is? We need to check it – I’ll have to take it away but of course it will come back to you as soon as we’ve finished with it.’

‘It’ll be in her school bag, though she sometimes emptied that out and put things in a drawer.’

‘May I come up? This is about my just – this may sound strange to you – just standing in her room and getting a sense of your daughter. An idea of her in the place she spent a lot of time.’

They stopped outside the closed door. Greta pushed it open, but as she took a step forward, she let out a couple of choked little sobs. ‘It smells of her. You wouldn’t know that.’ But then she went across to pick up the school bag from the floor beside Olivia’s desk, and held it out.