A second where those eyes didn’t blink, took in everything about me and gave back nothing. Then she stood up. She still shook hands like a little girl, pulling away too quick. ‘Hi, Stephen,’ she said.

Her voice was good. Clear and cool, not that cartoon squeal. The accent: high-end, but not the distorted ugly-posh. Her dad wouldn’t have let her away with that. Straight out of the blazer and into community school, if she’d brought that home.

‘What can I do for you?’

Lower: ‘I’ve got something to give you.’

That left me lost. Ten past nine in the morning, all uniformed up: she was mitching off, from a school that would notice; this wasn’t about a years-late thank-you card. ‘Yeah?’

‘Well, not here.’

The eye-tilt at our admin said privacy. A teenage girl, you watch yourself. A detective’s kid, you watch twice as hard. But Holly Mackey: bring in someone she doesn’t want, and you’re done for the day.

I said, ‘Let’s find somewhere we can talk.’

I work Cold Cases. When we bring witnesses in, they want to believe this doesn’t count: not really a murder investigation, not a proper one with guns and cuffs, nothing that’ll slam through your life like a tornado. Something old and soft, instead, worn fuzzy round the edges. We play along. Our main interview room looks like a nice dentist’s waiting room. Squashy sofas, Venetian blinds, glass table of dog-eared magazines. Crap tea and coffee. No need to notice the video camera in the corner or the one-way glass behind one set of blinds, not if you don’t want to, and they don’t. This won’t hurt a bit, sir, just a few little minutes and off you go home.

I took Holly there. Another kid would have been twitching all the way, playing head tennis, but none of this was new on Holly. She headed down the corridor like it was part of her gaff.

On the way I watched her. She was doing a grand job of growing up. Average height, or a little under. Slim, very slim, but it was natural: no starved look. Maybe halfway through getting her curves. No stunner, not yet anyway, but nothing ugly there – no spots, no braces, none of her face stuck on sideways – and the eyes made her more than another blonde clone, made you look twice.

A boyfriend who’d hit her? Groped her, raped her? Holly coming to me instead of to some stranger in Sex Crime?

Something to give you. Evidence?

She shut the interview-room door behind us, flick of her wrist and a slam. Looked around.

I switched on the camera, casual push of the switch. Said, ‘Have a seat.’

Holly stayed put. Ran a finger over the bald-patch green of the sofa. ‘This room’s nicer than the ones before.’

‘How’re you getting on?’

Still looking around the room, not at me. ‘OK. Fine.’

‘Will I get you a cup of tea? Coffee?’

Shake of her head.