‘Didn’t notice any unusual accents, so I guess they were from round here. I know I thought they were angry at each other. Speaking fast – and the words were all at the same time, like they were talking over each other.’

‘That’s really good, Melanie. Now, I want you to think about what you saw. Imagine where you were standing near the bushes. Remember which way you turned to go back inside. To your left or your right?’

‘My right,’ the girl said softly.

‘Good, now close your eyes again. It’s all still there in your memory. You’re outside, the ground is hard beneath your feet, because it hasn’t rained for a while. There’s some traffic noise from the road outside the school. You can hear the argument at a distance, and you know something unusual is going on. You need to get back inside and carry on working, because you haven’t finished your algebra yet. So you turn to your right to go back towards the library steps. Just hold it there. Don’t take a step yet. There’s a tree out there, right? Between the edge of the library and the car park exit. So you didn’t have a clear view to start with. When you begin to walk, which direction do you look in?’

‘I was already looking towards the voices, but the tree was in the way then. It’s leafy at the moment. As I reached the bottom of the library steps, it had all gone quiet. I took a couple of steps up, and by then I had a view past the edge of the tree. I could see the back of a man …’ She paused.

Connie held a hand up to DC Champion and Mrs Chao to keep them quiet.

‘Only at first I thought I wasn’t looking at the people whose voices I’d been hearing. I wasn’t sure it was a man.’ Melanie banged a hand on the desk. ‘I wasn’t sure it was a man because he was so thin, like really crazy thin, and he was wearing all denim. These super-skinny jeans and this jacket with a tight waist, and I remember thinking I’d seen clothes like that in the retro store and that I’d never seen a man that thin.’

‘His hair?’ Connie asked.

‘Don’t know. I think he had some sort of hat or cap, but I’m not sure. I remember just staring at his legs and thinking I’d never seen a grown-up with legs like that.’

‘Was he tall or short?’

She shrugged. ‘Kind of tall. I wasn’t close enough to compare him to me, but not, like, short or anything.’

‘Skin colour?’

‘White. Something happened when he closed the boot.’

Connie sat back in her chair. This time she didn’t need to persuade anyone else to keep the silence. Melanie was breathing hard, her face a knot of concentration, head tilted to one side. Mrs Chao had one hand over her mouth, and DC Champion was leaning in, pen at the ready.