‘I know that’s Audrey’s theory…and maybe she’s right. But. But.’ Petra grapples with something unseen. ‘I’m not a good person,’ she whispers eventually.

‘Let’s go outside.’ I grab Petra’s arm and take the doors outside to the breezeway. We lean on the waist-high balcony, looking down to the quad where the Year Sevens have been constructing a mandala out of flower petals. One breath of wind and the whole thing is going to blow away, which I guess is the point.

‘Why aren’t you a good person?’ I ask.

Petra doesn’t look at me. ‘Because…because I was always envious of Yin. She was first clarinet, I was second. We took all the same subjects and she always got slightly better marks than me. And everyone likes her—liked her—but I secretly thought of her as my nemesis. Even though she was so nice to me, so generous. She used to lend me her notes all the time, like we weren’t rivals.’

She falls quiet.

I try to understand what the problem is. ‘So you felt guilty when she went missing?’

‘A little.’ Petra wipes her nose and I see that she’s been silently crying. ‘I know logically that I have nothing to do with what happened to her, but I wish I had been nicer to her, accepted her friendship more. I can’t believe the things that used to matter to me.’

‘I get it,’ I say. I do. It’s hard not to pit yourself against other girls in the hothouse environment of Balmoral. ‘It makes sense.’

‘Thanks, Chloe. You’re the last person I would expect to listen to me.’

‘It’s done, right? Let’s try to move on, if we can. You might have to ignore Natalia for a while. She’s going through a lot, I think…’

‘I know.’

We’re both quiet. I had no idea I would do this but I step forward and give Petra a hug.

‘It’s been awful,’ she says. ‘The whole thing.’

‘I know,’ I say, and we separate. I’d feel embarrassed, but there’s been more hugging in the last three days than in the whole year combined.

‘I keep waiting to wake up and find out this has all been a nightmare.’ Petra extracts a tissue from her blazer pocket. ‘I knew what the chances were. Statistically speaking, you know. That whole thing about ninety per cent of kidnapping victims being dead within the first twenty-four hours isn’t a particularly accurate statistic, it’s more complicated than that, but it’s not far off.’

Something occurs to me for the first time. There’s something familiar about what she’s saying. ‘Petra—did you write the email about what to do in the case of an abduction?’

She flushes all over again. ‘Please don’t tell anyone. Not even Audrey knows.’