The pause before he speaks gives him away. ‘Can I ask what relevance this has to Hollie’s death?’

‘That’s what we’re trying to ascertain.’ My eyes don’t leave his. ‘Could you answer the question, Mr Calder? Did you and James Hampton ever talk about Philip Mason?’

He blusters. ‘Maybe. I’ve met Phil once or twice, of course – in the pub. It’s a small village, Detective Sergeant.’

*

‘His manner totally changed, sir,’ I tell the DI. ‘He made it clear he didn’t want to talk to me. One minute he was polite, but the instant I asked about Mason, he changed. He knows him all right – he just didn’t want to give me anything to pick up on.’

The DI frowns. ‘Did he tell you anything about Hollie?’

I shake my head. ‘It’s the same with everyone we’ve talked to. We’re still waiting for the tech team to get back to us. Hopefully then, we’ll have the proof we need to put potential suspects like Mason and Andrew Buckley in the frame, but it’s going to take time.’

‘Forensics has been going over the photos. They’ve linked a few of them to cases of missing girls, but so far, that leaves most of them unaccounted for.’ He pauses. ‘They’re cross-checking with cases around the country. Those girls – children – must have come from somewhere, May.’

I nod. We need to find out where.

‘And we can’t afford to wait.’ He’s silent for a moment. ‘We must have missed something. Go over everything again, May. We need to find the needle in Abingworth’s haystack.’

I nod. But I’m filled with a sinking feeling at the prospect of days at my desk, reading through everyone’s notes. We’re no closer to knowing if there’s any connection between Hollie’s death and Mason, or anyone connected to him. But there’s still one person who might know something. ‘Before I do, sir, there’s someone I want to talk to again.’

*

I wait near the bus stop outside Niamh’s school, searching the dozens of faces of students pouring out through the gates. She’s alone when I see her, her expression shuttered, unreadable. As I walk towards her, she looks up.

‘Hello, Niamh. Do you mind if we have a quick chat?’

She shakes her head. ‘I’ll miss my bus.’

I hesitate. ‘If you like, I could give you a lift home?’

As she stands there, I wonder what’s going through her head. I’m fully expecting that she’ll insist on catching her bus, but then she nods. ‘OK.’

‘I saw your mum this morning,’ I say as we walk towards my car, watching a startled look cross Niamh’s face. ‘I had to go to the hospital anyway,’ I add. ‘To see someone else. I’d heard she’d had a fall.’

Niamh looks anxious. ‘Was she OK?’