‘Right.’ Izzy took a deep breath. ‘Have I got this right? The boy you go to meet every day is the memory of a missing boy from twenty years ago?’ She smiled a bit. ‘Can we just clarify – not an older man who’s getting you to send him nudes.’ She paused. ‘Not someone who’s saying he’s the real Joe Simpson, all these years later, for example?’

‘Oh God, Izzy! Definitely not that. Nothing like that at all. I have to find out what happened to Joe Simpson. I just have to. It’s because of Mum. There’s no mystery about what happened to her. She got sick and she died, and I was there through it all. It was no one’s fault. Not that part. With Mum, it’s straightforward. She died and we scattered her ashes. And that makes me feel so terrible for Joe’s family because twenty years later they don’t know what happened. Whether he ran away or committed suicide, but I don’t think he did either of those things.’

We were getting close to Manor Park Primary. I slowed my pace.

‘You don’t know,’ she said. ‘You really don’t, Ariel. Mental-health issues in boys are complicated, and back then there’d have been less awareness.’

‘I know,’ I said as we approached the gates. ‘But I don’t think that’s what it was. Look, I’ll tell you more later. I need to get the girls. I guess you have to leave now?’

She checked the time again. ‘Four ten? I’ve got a bit longer. Where do they live?’

‘By the cricket pitch.’

‘Perfect. That’s on my way. I’ll walk with you and them, if that’s OK. And I’ll tell you my stuff on Saturday, if we’re still going for our day trip?’

She looked at me, expectant.

‘Of course we are!’ I said. ‘But if you’re going to meet them you probably need to know one more thing. This is kind of what got me into this babysitting business in the first place.’

She looked at me, a question on her face.

‘Ms Duke is married to Joe Simpson’s dad. And these two girls are Joe’s brother’s children. They’d be his nieces.’

I walked fast up to the school so she couldn’t say anything.

The girls were happy to see me, and Zara wasn’t shy any more. She warmed slowly to Izzy, while Coco danced around her and talked her through her school day in meticulous detail.

‘And then we went outside,’ she said. ‘And there was a game of It, but I didn’t want to play, so we got a football and we played football instead, but …’ It went on and on.

‘I’m happy that you’re here,’ said Zara as we dropped behind Coco and Izzy. ‘We told Mummy we wanted you.’