‘And did he?’

‘I do remember seeing Rory on the house payphone . . . it was Thursday, yes, the day before Cavendish was found dead.’

‘But you don’t know it was David Millar on the other end of the line?’

Frederiks shrugged. ‘No, I don’t, but the thing was . . . actually . . .’ He scratched his head.

‘Yes, Mr Frederiks?’

‘I’ve just thought of something. The day after I saw Rory on the payphone, which was the Friday that Charlie died, I went off for my meeting around seven thirty that evening. I was just pulling out of the school car park, when by coincidence I saw David Millar getting out of his car.’

‘I see.’

‘There were a lot of parents arriving for the concert in the chapel. Rory was in the choir, so it may have been that Millar was coming to listen to his son. But’ – Frederiks shrugged again – ‘I’ve never seen him in chapel before.’

‘I presume Mr Millar’s car was gone by the time you arrived back at school that night?’ Jazz probed.

‘Of course. I’ve told you, it was midnight when I returned, or thereabouts. Look, Inspector, I’m not suggesting anything to you, but what if Rory had confided in his dad about his suspicion it was Cavendish who’d locked him in the cellar?’

‘So you now admit Charlie was targeting him?’ Jazz pressed.

‘A lot of ribbing goes on between boys. Some can cope, some can’t. The bottom line is that Rory couldn’t. And yes,’ Frederiks sighed, ‘I accept I should have interceded before. And now he’s run away . . . but . . .’ Frederiks looked puzzled.

‘What?’

‘It doesn’t fit, does it? I mean, if young Rory had been targeted by Charlie, surely he’d be ecstatic now he’s no longer here? Why on earth would he run away?’

‘We’ve no idea.’ Jazz decided to change the subject, not wishing to speculate on aspects of the case with a possible suspect. ‘Mr Frederiks, I need to ask you again where you were that Friday evening?’

‘I really can’t say.’

‘Do you know it is an offence to withhold information relevant to a police enquiry?’

‘Look, Inspector, I can only reiterate that where I was that Friday night is not relevant to your case.’

‘Let me be the judge of that, Mr Frederiks. And I’d say it is. You were the person who’s admitted he placed Charlie Cavendish’s Epilim by his bedside before you left. We have no proof it wasn’t you who substituted the tablets in the first place.’

‘Then why on earth, if I had done it, would I have told you I had put the tablets there?’

‘Because it was fact, and recorded on the drug sheet. And you may have thought Charlie’s death would be uncontested; a simple case of an epileptic fit . . .’

‘That is what we all thought, Inspector . . .’

‘And that your actions would not be questioned . . .’