‘We just chatted. She talked about her dad, and what she’d bought him for his birthday, and she said she was looking forward to the field trip to the Peak District. I filled her in on some new gamma-ray bursts that have been discovered by ESA’s Integral satellite, and that’s all, really.’

‘Thrilling! And you didn’t think to ask her why she specifically needed to see you?’ Nikki didn’t bother to keep the derisory tone from her voice.

‘But we often have a coffee. It was nothing new.’ He frowned. ‘Kerry sometimes likes to just off-load, you know? And she knows that she can to me.’ He stared directly at Nikki. ‘People think it’s all so easy for her, but it isn’t.’

‘Okay. So what sort of mood was she in?’

Brown thought for moment. ‘Upbeat about the field trip, but—’

‘But?’ asked Joseph.

Brown didn’t answer immediately.

‘My sergeant asked you a question.’ growled Nikki.

‘Well, I didn’t think too much about it at the time, but now …’ he rubbed hard at his temple, ‘… now, I get the feeling that something could have been bothering her. The fact that she was all fired up for the trip kind of masked it, but on reflection, maybe she was too hyped up.’

It was Nikki’s turn to frown. She’d played this all wrong. She’d given Kris Brown too much time to work out a retrospect scenario where Kerry was already worried about something. Time to move on.

‘So, when did you speak to her last?’

‘But I just told you!’

‘No, Mr Brown, you told me when you last saw her, not when you spoke last.’

‘That was it! I haven’t spoken to her since.’

‘No phone calls? No text messages?’ Nikki kept her voice expressionless.

‘No, none.’

Nikki frowned. ‘Do you have a mobile phone, Mr Brown?’

Kris Brown looked at her as if she were in need of mental care. ‘Yeah.’

‘Can I see yours, please?’

‘Sure.’ He moved across to a row of coat hooks by the front door and pulled a light jacket down. He plunged his hand deep into the pocket, then pulled it out and tried the other pocket. ‘That’s odd.’ He murmured, almost to himself. ‘I thought—’

‘Having trouble finding it, sir?’ asked Joseph. ‘I thought you young people were superglued to your phones?’

Brown frowned. ‘Not me.’

‘Why? Bit of a loner, are you? Not many friends? Except Kerry, of course.’ As Nikki stared at him she saw him begin to gnaw on his bottom lip. And she wasn’t sure if he were nervous, frightened, or just acting at one of the aforementioned emotions.

‘I think I have a right to know what has happened to Kerry.’ There was a tremor in his voice.

‘Where were you last night, Mr Brown?’

He tensed. ‘I was here.’

‘Was anyone with you?’