That sort of stops me dead for a moment and then I do this jerky head nod and continue on my way, singing to myself la la la because it seems like the teachers actively want us to never think about Yin again and at the loans desk Mrs Berryman looks at me like I’m trying to steal Picnic at Hanging Rock, not borrow it.

‘It’s not on your English list anymore,’ she says.

‘I know.’ I slap my library card down. ‘And yet, here I am.’

I put my world-mufflers back on while she says something else, but she might as well be talking to me through a tin can and string. No, scratch that. She might as well be talking to me from a very distant planet.

DAY 19

The pretence of normal lasts until about two minutes into History when Mr Wright announces that a police officer is gatecrashing and before you know it, there she is in the doorway.

They’ve picked a young policewoman so that we can relate to her and everything, but quite frankly I’m surprised that Mrs Christie has let us be exposed to the people in blue at all. The principal has been blowing off steam about predatory journalists after several students were approached at the Junction last week, and you pretty much get the feeling she would like to turn Balmoral into a moat-circled fortress, inside of which we put equal effort into protecting our virginities and our grades.

This is how the policewoman starts:

‘Hi, I’m Celeste, and I’m part of the team investigating Yin’s disappearance.’

She uses Yin’s name, but she doesn’t say ‘home invasion’ or ‘abduction’ like they do on the news. Disappearance is a watered-down, inaccurate word and I immediately get an itch on the back of my knees.

The policewoman sits on the edge of the teacher’s desk, like Nouri does, and she kicks her feet as she talks and she has her hair in a low bun and they’ve picked her well because with her countryish round freckled face you might trust her so much you’d be able to tell her anything.

‘It must have been a really scary couple of weeks for you, so I’ve come in today to tell you what’s going on and answer any questions you have.’

She runs over the official police line, but it’s the same as what’s on the TV and in the papers and what I hear when I eavesdrop on my parents’ phone calls to their friends by picking up the spare phone in the entertainment room. My head starts up with the blah blah blah and prickly fire creeps up my legs and I have to refocus hard.